Nausea and vomiting

• Nausea is the unpleasant, painless sensation that one may potentially vomit. Vomiting is an organized, subconscious response that ultimately results in the forceful expulsion of gastric contents through the mouth and sometimes the nose. Vomiting is intended to protect a person from harmful ingested substances.
• Nausea and vomiting are not diseases. They can be symptoms of many different conditions. Conditions causing nausea and vomiting include cough, food poisoning, infections, medications such as cancer chemotherapy drugs or opiates, migraine headaches, hyperemesis gravidarum (morning sickness during pregnancy), motion sickness or seasickness, over-eating, and post-operative nausea and vomiting. Nausea and vomiting may also be symptoms of serious conditions including heart attack, blocked intestines, concussion or brain injury, and appendicitis (inflammation of the appendix). Chronic (long-term) nausea and vomiting may be a sign of serious illness, such as cancer.
• Nausea and vomiting are common and are not normally serious. Individuals should see a doctor immediately if they have: vomited for longer than 24 hours; blood in the vomit; severe abdominal pain; headache and stiff neck; and signs of dehydration, such as dry mouth, infrequent urination, or dark urine.
• Nausea and vomiting can occur in both adults and children. However, adults with vomiting are at a much lower risk of dehydration, or the loss of fluids from the body. Adults can also tell by thirst and other symptoms when they become dehydrated.

• It is thought that vomiting is controlled by the vomiting center located in the brain called the chemotrigger zone. Nausea is less well understood. The timing of the nausea or vomiting can indicate the cause. When it appears shortly after a meal, nausea or vomiting may indicate a mental disorder, such as bulimia, or a peptic ulcer. Nausea or vomiting one to eight hours after a meal may indicate food poisoning. Food borne diseases, such as Salmonella, may take eight to 72 hours after eating contaminated food to produce symptoms because of the incubation time.
• Chemotherapy induced nausea and vomiting: Chemotherapy medications are commonly used to treat various types of cancers. Some chemotherapy medications cause more nausea and vomiting than others, including cisplatin (Platinol®) and cyclophosphamide (Cytoxan®). These two drugs cause nausea and vomiting in greater than 90% of those receiving the drug when no nausea treatment is given.
• Chemotherapy induced nausea and vomiting can be divided into several categories. Acute nausea and vomiting usually occurs a few minutes to several hours after the chemotherapy is initiated and goes away within the first 24 hours. The vomiting will be at its worst usually after five to six hours. Delayed vomiting develops more than 24 hours after chemotherapy is given. It might occur with cisplatin (Platinol®) or cyclophosphamide (Cytoxan®). Cisplatin-related vomiting will be at its worst usually from 48-72 hours following chemotherapy and can last six to seven days. Anticipatory nausea/vomiting is learned from previous experiences with vomiting. Anticipatory nausea and vomiting occurs as a result of an unpleasant experience with chemotherapy. It occurs as the individual is preparing for the next dose of chemotherapy, usually within 30-60 minutes before the chemotherapy is started. The individual anticipates that nausea and vomiting will occur as it did before. Breakthrough vomiting occurs despite treatment to prevent it. It requires more anti-nausea and vomiting treatment. Refractory vomiting occurs after one, a few, or several chemotherapy treatments even though the individual is being treated to prevent or control nausea and vomiting. The anti-nausea and vomiting treatment is no longer effective. The individual no longer responds to treatment to prevent nausea and vomiting.
• Diabetes: Diabetes can cause nausea, especially when blood sugar levels are poorly controlled. Blood sugar levels of 100-125 milligrams/deciliter indicates an individual has a form of pre-diabetes called impaired fasting glucose (IFG), meaning that the individual is more likely to develop type 2 diabetes but does not have the condition yet. A level of 126 milligrams/deciliter is diabetes. Diabetes can lead to a condition of the stomach called gastroparesis, which also can cause nausea and difficulty eating. Gastroparesis causes stomach contents to not be emptied quickly enough, resulting in nausea.
• Emotional stress: Sensitive individuals under extreme emotional stress may become nauseous and vomit.
• Gallstones: Gallstones are solid deposits of cholesterol or calcium salts that form in the gallbladder or nearby bile ducts. Gallstones may cause nausea, vomiting, indigestion, and abdominal pain.
• Gastroenteritis: Gastroenteritis is inflammation of the lining of the stomach and intestines. Gastroenteritis is typically caused by a viral infection or bacteria from contaminated food or water. In addition to nausea and vomiting, the individual may have watery diarrhea and abdominal cramps.
• Gastroesophageal reflux disease (GERD): Gastroesophageal reflux disease (GERD) is irritation to the esophagus that causes inflammation. GERD is often due to stomach acid that backs up into the esophagus Stomach acid in the lower esophagus can trigger nausea and regurgitation of food. It may also be associated with vomiting. Foods and beverages that may cause GERD include alcoholic beverages, soft drinks, tea, and coffee.
• Headache: An intense headache, such as a migraine, can cause nausea and vomiting. A rare cause of headache and nausea with vomiting is a brain tumor.
• Kidney failure: Nausea and vomiting may develop if the kidneys are not able to rid the body or toxins effectively, such as in nephritis.
• Liver disease: If the liver becomes inflamed, called hepatitis, the individual may experience nausea and vomiting. If the liver is damaged to the point of liver failure, waste products are not removed effectively and nausea and vomiting may result. Hepatitis can result from a viral infection, chronic alcohol abuse, and certain medications, including acetaminophen (Tylenol®).
• Motion sickness: Motion sickness is a normal response to real, perceived, or anticipated movement. Individuals tend to experience motion sickness on a moving boat (seasickness), train, airplane, automobile, or amusement park rides. Although this condition is fairly common and only a minor nuisance for the occasional traveler, it may be incapacitating for people with an occupation that requires constant movement, such as a flight attendant, pilot, astronaut, or ship crew member. Symptoms generally consist of dizziness, fatigue, and nausea, which may progress to vomiting. Fortunately, most symptoms disappear once the journey is over. Treatment can include over-the-counter (OTC) antihistamines including dimenhydrinate (Dramamine®) and integrative therapies including acupressure and ginger (Zingiber officinale).
• Pancreatitis: Pancreatitis is a condition where digestive enzymes attack the pancreas rather than break down food in the small intestine. Pancreatitis causes mild to severe abdominal pain, often accompanied by nausea, vomiting, and fever.
• Peptic ulcers: Peptic ulcers are lesions that develop on the lining of the stomach, upper small intestine, or esophagus. The classic symptom of peptic ulcer is burning pain anywhere from the navel to the breastbone, but peptic ulcers may cause nausea and vomiting as well.
• Pregnancy: It is estimated that 50-90% of pregnant women experience nausea during the first trimester, while 25-55% experience vomiting. The hormonal changes of early pregnancy have been thought to cause nausea and vomiting. For most women, nausea begins between the 2 and 5 week and ends between the 8 and 14 week post-conception. For 35% of pregnant women, nausea and vomiting are severe enough that they lose time from work.
• Radiation therapy nausea and vomiting: Whether radiation therapy causes nausea and vomiting depends on the part of the body being treated, the amount of radiation given, and how often the treatment is given. When the area of the body being treated includes a large part of the abdomen, specifically, the small intestine (or small bowel), there is a greater chance of nausea and vomiting occurring. About 50% of the people with cancer who receive standard doses of radiation to their abdomen will have nausea and vomiting. These symptoms can occur one to two hours after treatment and can last for several hours. Of those being treated with total body radiation therapy used in bone marrow transplants, about 60-90% will develop nausea and vomiting if not given preventative medicines. These people may also receive high doses of chemotherapy to prepare for the transplant. The combination of radiation therapy and chemotherapy increases the chance of nausea and vomiting. Individuals who receive one large dose of radiation therapy (500 rem or more) have a greater chance of nausea and vomiting than those who receive radiation therapy in smaller doses (less than 100 rem).
• Toxins: Toxins in the blood, including alcohol, nicotine, and medications (such as antibiotics), can cause nausea and vomiting. Withdrawal from addictive substances, such as narcotic pain relievers and heroin, can lead to nausea and vomiting.

• Nausea is a subjective sensation that is difficult to define. It is an unpleasant feeling in the abdomen often associated with the sense of being ill and the urge to vomit. Vomiting (emesis) is the forcible expulsion of stomach contents through the mouth. Retching is a strong, belching-like, rhythmic movement that may or may not be followed by vomiting.
• Other related symptoms include increased salivation, loss of color, sweating, tachycardia (increased heart rate), and the urge to defecate.
• Usually, nausea and vomiting lasts only a short period of time (several minutes). Medical care should be sought if any of the following symptoms occurs with nausea and vomiting: very forceful vomiting; high fever, over 101 degrees Fahrenheit; severe headache or pain; diarrhea; blood in the vomited material, which may look red or brown, like coffee grounds; heavy sweating; or unusual weakness; if the nausea lasts for more than a few days; if there is a possibility of being pregnant; if home treatment is not working; if symptoms of dehydration are present, including thirst, cramping in the arms and legs, dizziness, restless or irritable behavior, decreased skin tone, dry mucous membranes (such as lips and mouth), sunken eyes, weakness, and fatigue; or a known injury has occurred (such as head injury or infection) that may be causing the vomiting.
• Infants may have sunken eyes, a sunken fontanelle (soft spots), and absence of tears when crying vigorously. Infants and children (under six years of age) should be taken to a doctor if vomiting lasts more than a few hours, diarrhea is present, signs of dehydration occur, there is a fever higher than 100 degrees Fahrenheit, or if the child has not urinated for six hours.

• Medical history and physical examination: A comprehensive history and physical examination can often reveal the cause of nausea and vomiting, making further evaluation unnecessary. Doctors will ask about the individual's medical history, surgeries, and medications. A thorough history of recreational drug and alcohol use or abuse is equally important.
• A complete physical examination will include a neurological examination and brain function tests. Acute symptoms generally are the result of infectious, inflammatory, or unknown causes. Evaluation first focuses on detecting any emergencies or complications that require hospitalization, such as bowel obstruction, cancer, opiate addiction, or increased pressure in the head.
• Blood tests: Blood tests will be performed to determine if the individual is dehydrated. Blood tests may include electrolyte levels, such as sodium, potassium, and chloride. Tests for kidney function may also be performed, including blood urea nitrogen (BUN) and serum creatinine levels.
• Diagnostic tests: Further testing, such as upper endoscopy or computed tomography of the abdomen, may be used by a doctor when an underlying condition, such as bowel obstruction or peptic ulcer, may be the cause of the nausea and vomiting. Upper endoscopy uses a long, narrow tube with a small attached camera that is threaded down the throat and esophagus into the stomach and duodenum. With this instrument, the doctor can view the upper digestive tract and identify an ulcer. If the doctor detects an ulcer, they may remove small tissue samples near the ulcer. Possible complications of upper endoscopy include bleeding and puncture of the stomach lining. However, such complications are rare. Most people will have nothing more than a mild sore throat after the procedure. The procedure takes 20-30 minutes. Because the individual will be sedated, they will need to rest at the endoscopy facility for 1-2 hours until the medication wears off. It is recommended to have a friend or loved one drive. Computerized tomography (CT) scan is an x-ray that uses computer technology and can be enhanced with the injection of a contrast dye. Computerized tomography (CT) scans allow for multiple X-rays to be taken from different angles to create a three-dimensional image of internal body structures. CT is used to show abnormalities in bones and soft tissue. CT scan can be used to look at the abdomen in individuals with severe nausea and vomiting to determine if bowel obstruction may be the cause.

• Underlying conditions: Nausea and vomiting are usually harmless, but in some cases may be a sign of a more serious illness. Some examples of serious conditions that may result in nausea or vomiting include concussions or brain injuries, meningitis (infection of the membrane linings of the brain), intestinal blockage, appendicitis, and brain tumors.
• Dehydration: Another concern is dehydration. Adults have a lower risk of becoming dehydrated because they can usually detect the symptoms of dehydration, including increased thirst and dry lips or mouth. Children have a greater risk of becoming dehydrated, especially if they also have diarrhea. Young children are often unable to communicate symptoms of dehydration. Adults caring for sick children should be aware of these visible signs of dehydration: dry lips and mouth, sunken eyes, and rapid breathing or pulse. In infants, decreased urination and a sunken fontanelle (soft spot on the head) may occur.
• Hyperemesis gravidarum: Recurrent vomiting in pregnancy can lead to a serious condition called hyperemesis gravidarum, where the mother may develop fluid and mineral imbalances that can endanger her life or that of her unborn child. Hyperemesis gravidarum is characterized by persistent vomiting, protein in the urine, severe weight loss, and dehydration. This condition affects approximately 0.5-2% pregnant women and, if left untreated, can lead to coma, convulsions, and fetal loss. Up to 60% of women who suffer from hyperemesis gravidarum develop depression. Treatment may involve anti-nausea medications (such as 5-HT3 inhibitors), intravenous (IV) fluids (such as normal saline), enteral nutrition (such as Osmolite® or Ensure®). Enteral nutrition is a way to provide food to the body through a tube placed in the nose, the stomach, or the small intestine.

• Home treatment :
• Healthcare professionals recommend that individuals experiencing nausea and vomiting: drink clear liquids only, but in specified amounts depending upon size and weight of the individual; eat no solid food until the vomiting episode has passed; get plenty of rest as more movement and exertion may worsen the symptoms of nausea and vomiting; and stop all medicine temporarily until the vomiting subsides. Alerting a doctor is recommended by healthcare professionals in the following situations: if the individual is on medications for serious illnesses such as diabetes and heart conditions; if vomiting persists more than one day; or if vomiting and diarrhea are both present.
• Oral rehydration therapy (ORT) :
• Oral rehydration therapy (ORT) is a simple, cheap, and effective treatment for diarrhea-related dehydration. ORT consists of a solution of salts and other substances such as glucose, sucrose, citrates, or molasses that is administered orally. It is used around the world, but is most important in developing countries, where it saves millions of people from diarrhea. Diarrhea is the leading cause of death in developing countries. Commercial examples of ORT include sports drinks (such as Gatorade®), CeraLyte®, and Pedialyte®. Dehydration is the most important complication of persistent vomiting. If the following symptoms are present, oral rehydration therapy should be given immediately: vomiting and fever over 101 degrees are present; vomiting and diarrhea are present; vomiting alone persists for more than 12 hours in children under six years or 24 hours in older children and adults; any physical signs of dehydration are present such as dry lips and mouth membranes, sunken eyes and fontanelle (soft spot on baby's head), and rapid breathing or pulse.
• Over-the-counter (OTC) medicines :
• Bismuth subsalicylate: Bismuth subsalicylate (Kaopectate®, Pepto-Bismol®) may help treat some types of nausea and vomiting, such as from the flu (influenza). Bismuth subsalicylate preparations are also used for upset stomach and as an anti-diarrheal (medicine to treat diarrhea). It is not recommended to take bismuth subsalicylate if the individual ever had an allergy to aspirin or any other product that contains salicylates. Also, bismuth subsalicylate should not be given to children who may have any viral infection such as the flu or chickenpox because they will have a higher risk of Reye's Syndrome (a condition affecting all organs, especially the liver and brain).
• Antihistamines: Certain antihistamines may help prevent nausea and vomiting caused by motion sickness. These include dimenhydrinate (Dramamine®) and meclizine hydrochloride (Bonine®). Meclizine is also available as a prescription drug (Antivert®). OTC antihistamines for nausea and vomiting may cause drowsiness, sedation, dry mouth, and constipation.
• Phosporylated carbohydrate syrup (Emetrol®): Emetrol® is a pleasant tasting syrup that has a soothing effect on irritated stomach lining, over eating, food intolerance, or other types of indigestion.
• Carbohydrate and electrolyte powder packets (Kaolectrolyte®): Carbohydrate and electrolyte powder packets (Kao Lectrolyt®) closely approximate World Health Organization (WHO) guidelines on oral rehydrating solutions. Because they come in small, easily transportable packets and dissolve in 8 oz. of water in seconds, they are more convenient than pre-mixed solutions or liquids. They also come in several flavors (artificial), including grape and bubble gum.
• Prescription medicines :
• Prescription medications for nausea and vomiting include: the antidepressant drugs amitriptyline (Elavil®) and nortriptyline (Pamelor®), the anti-anxiety drug lorazepam (Ativan®), and the antihistamine patch scopolamine (Transderm-Scop®). These medications may cause drowsiness, dry mouth, and fatigue.
• 5-HT3 inhibitors: 5-HT3 inhibitors help prevent and relieve nausea and vomiting from surgery or chemotherapy. Researchers believe that nausea and vomiting during chemotherapy is associated with the release of 5-HT3 (serotonin) from special cells in the small intestine. 5-HT3 inhibitors block these nerve endings in the intestine and prevent signals to the central nervous system. 5-HT3 inhibitors may cause drowsiness, sedation, constipation, and dry mouth. Examples of 5-HT3 inhibitors include ondansetron (Zofran®), dolasetron (Anzemet®), and granisetron (Kytril®).
• Prochlorperazine (Compazine®): Prochlorperazine (Compazine®) helps control nausea and vomiting after surgery or chemotherapy. Prochlorperazine is available in capsule, tablet, liquid, suppository, or injection. Prochlorperazine can cause drowsiness and may interact with other medications or alcohol. Prochlorperazine may cause drowsiness, sedation, constipation, and dry mouth.
• Promethazine (Phenergan®): Promethazine (Phenergan®) has sedative, antihistamine, and mild anti-nausea properties. It may be used to help prevent or treat nausea due to chemotherapy. Promethazine may be available in tablet form or as an oral syrup, suppository, or injection. Promethazine may cause drowsiness, sedation, constipation, and dry mouth.
• Corticosteroids . Corticosteroids, including methylprednisolone (Medrol®), have been reported effective in relieving nausea and vomiting associated in women with refractory hyperemesis gravidarum. Corticosteroid therapy generally is considered safe during pregnancy, but side effects such as water retention are monitored closely.
• Intravenous fluids: Individuals who, despite the previously discussed treatments, are unable to keep down liquids will probably require intravenous (IV) fluids, such as normal saline. IV fluids may provide relief from nausea and vomiting, but many individuals also require an anti-emetic administered orally, rectally, or by infusion. Depending on the severity of the symptoms, intravenous fluid therapy may be given in the hospital or at home by a visiting nurse.
• Enteral or parenteral nutrition: Enteral (feeding through a tube into the stomach or small intestine) and total parenteral nutrition (TPN, or feeding through the veins) are last-resort treatments for individuals who continue to vomit and lose weight despite aggressive treatment.

A Strong scientific evidence

• Acupressure, shiatsu : Shiatsu technique involves finger pressure at acupoints and along body meridians. It can incorporate palm pressure, stretching, massaging, and other manual techniques. Numerous scientific studies support the use of wrist acupressure at the P6 acupoint (also known as Neiguan) in the prevention and treatment of nausea after surgery, intra-operative nausea (during spinal anesthesia), nausea from chemotherapy, as well as pregnancy related nausea/vomiting and morning sickness. However, results from studies are conflicting. Effects have been noted in children as well as adults. Better quality research is needed.
• Acupressure appears to be safe if self-administered or administered by an experienced therapist. Serious, long-term complications have not been reported, according to available scientific data. Hand nerve injury and herpes zoster ("shingles") cases have been reported after shiatsu massage. Forceful acupressure may cause bruising.

B Good scientific evidence

• Acupuncture : The practice of acupuncture originated in China 5,000 years ago. Today, acupuncture is widely used throughout the world and is one of the main pillars of traditional Chinese medicine (TCM). Evidence from several small studies supports the use of acupuncture at a specific point on the wrist (P6) to help with chemotherapy-induced nausea. Evidence also supports acupuncture at the wrist P6 point for the relief of post-operative nausea and vomiting in adults.
• Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, infections, bleeding disorders, medical conditions of unknown origin, neurological disorders, or if taking anticoagulants. Avoid on areas that have received radiation therapy and during pregnancy. Avoid electroacupuncture with irregular heartbeat or in patients with pacemakers. Use cautiously with pulmonary disease (like asthma or emphysema). Use cautiously in elderly or medically compromised patients, diabetics, or with a history of seizures.
• Acustimulation : Acustimulation is the mild electrical stimulation of acupuncture points to control symptoms such as nausea and vomiting. A low-intensity electrical current is used to penetrate just slightly below the surface of the skin. There is evidence from small but well-designed studies of seasickness and artificially-induced motion sickness (using laboratory equipment) indicating that acustimulation can reduce symptoms of nausea and vomiting. It may slow down, but not necessarily prevent, the development of motion sickness.
• There is good evidence that wearing the ReliefBand® helps reduce post-operative nausea and vomiting. The effect may be comparable to anti-nausea medications (dimenhyrinate) and may be enhanced when combined with medication. The ReliefBand® is worn like a wristwatch on the inside of the wrist. It stimulates the nerves in the wrist with gentle electrical signals, which are believed to interfere with nausea-inducing messages between the brain and the stomach.
• Avoid if the cause of medical symptoms is unknown. Acustimulation devices may cause slight skin irritation under the electrodes when the wristband is used. Switch wrists to avoid. Acustimulation devices should only be used on the designated area. Use cautiously with pacemakers. Keep acustimulation devices out of the reach of children.
• Ginger : Preliminary studies suggest that ginger (Zingiber officinale) may be safe and effective for nausea and vomiting in pregnancy when used at recommended doses for short periods of time (less than five days). Some publications discourage large doses of ginger during pregnancy due to concerns about mutations or abortion. Additional research is needed to determine the safety and effectiveness of ginger during pregnancy.
• Avoid if allergic to ginger or other members of the Zingiberaceae family (like red ginger, Alpinia purpurata, shell ginger, Alpinia zeru, green cardamom, and balsam of Peru). Avoid with anticoagulation therapy. Avoid large quantities of fresh cut ginger with inflammatory bowel disease or with a history of intestinal obstruction. Use cautiously before surgery or with gastric or duodenal ulcers, gallstones, heart disease, or diabetes. Use cautiously long-term. Use cautiously in underweight patients. Use cautiously if taking heart medications or sedatives and if driving or operating heavy machinery. Use cautiously if pregnant or breastfeeding.
• Music therapy : Music is used to influence physical, emotional, cognitive, and social well-being and improve the quality of life for healthy people, as well as those who are disabled or ill. It may involve either listening to or performing music, with or without the presence of a music therapist. Music therapy helps in a wide range of pain conditions, primarily by its ability to improve mood, encourage relaxation, and elevate pain threshold. Music therapy may reduce nausea and vomiting in bone marrow transplant patients during the preparatory period when they are receiving high-dose chemotherapy with cyclophosphamide (Cytoxan®).
• Music therapy is generally known to be safe.

C Unclear or conflicting scientific evidence

• Acupuncture : Several attempts have been made to document benefits of stimulation of the P6 wrist point to reduce post-operative nausea and vomiting in children. Both acupuncture and acupressure wrist bands have been tried. Study results conflict. More trials are needed to make any firm conclusion regarding the use of acupuncture in adults and children.
• While several studies have suggested the related techniques of acupressure and other forms of nerve stimulation at the P6 wrist point may improve nausea during pregnancy, little study has been applied to use of acupuncture itself for this purpose. Thus the evidence in insufficient for reaching conclusions about acupuncture for nausea and vomiting of pregnancy.
• Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, infections, bleeding disorders, medical conditions of unknown origin, neurological disorders, or if taking anticoagulants. Avoid on areas that have received radiation therapy and during pregnancy. Avoid electroacupuncture with irregular heartbeat or in patients with pacemakers. Use cautiously with pulmonary disease (like asthma or emphysema). Use cautiously in elderly or medically compromised patients, diabetics, or with a history of seizures.
• Acustimulation : Transcutaneous acupoint electrical stimulation has been tested in limited available study of patients receiving electroshock therapy for mental illness, to determine whether it might reduce nausea and vomiting. The design of the study makes interpretation of results difficult. Therefore, more studies are needed to determine the potential benefits of acustimulation for electroconvulsive therapy-related nausea and vomiting.
• The evidence on the use of acustimulation wristbands for chemotherapy-induced nausea and vomiting is mixed. Some studies suggest no benefit and that simple acupressure massage may be more effective. Other studies have found benefit that when acustimulation is combined with anti-nausea medications; acustimulation bands may reduce the amount of medication needed and they may help with more severely nauseous patients. More studies are needed to clarify the relationships between patient responses, types of cancer, and types of chemotherapy.
• There is a lack of solid evidence on the effects of acustimulation for nausea and vomiting of pregnancy. Although experts express a general opinion that it is likely beneficial, well-designed studies are needed to document the benefits.
• Avoid if the cause of medical symptoms is unknown. Acustimulation devices may cause slight skin irritation under the electrodes when the wristband is used. Switch wrists to avoid. Acustimulation devices should only be used on the designated area. Use cautiously with pacemakers. Keep acustimulation devices out of the reach of children.
• Aromatherapy : Aromatherapy is a technique in which essential oils from plants are used with the intention of preventing or treating illness, reducing stress, or enhancing well-being. Preliminary evidence suggests that there may be no effect of aromatherapy on postoperative nausea and vomiting other than might be attributable to simple breathing or placebo effects. More studies are needed to determine whether or not aromatherapy may contribute to well-being in post-operative patients.
• Essential oils should be administered in a carrier oil to avoid toxicity. Avoid with a history of allergic dermatitis. Avoid consuming essential oils. Avoid direct contact of undiluted oils with mucous membranes. Use cautiously if driving/operating heavy machinery. Use cautiously if pregnant.
• Ginger : Some studies report that ginger has no effect on motion sickness, while other research notes that ginger may reduce vomiting (but not nausea). More studies are needed comparing ginger to other drugs used for this purpose.
• Initial human research reports that ginger may reduce the severity and duration of chemotherapy-induced nausea and vomiting. Other studies show no significant effects. Additional studies are needed to confirm these results and to determine safety and dosing. Numerous prescription drugs, such as 5HT3 inhibitors, are highly effective at controlling nausea in cancer patients undergoing chemotherapy, and the available options should be discussed with the patient's medical oncologist.
• Some human studies report improvement in postoperative nausea or vomiting if patients take ginger before surgery. However, other research shows no difference. Additional studies are needed.
• Avoid if allergic to ginger or other members of the Zingiberaceae family (like red ginger, Alpinia purpurata, shell ginger, Alpinia zeru, green cardamom, and balsam of Peru). Avoid with anticoagulation therapy. Avoid large quantities of fresh cut ginger with inflammatory bowel disease or with a history of intestinal obstruction. Use cautiously before surgery or with gastric or duodenal ulcers, gallstones, heart disease, or diabetes. Use cautiously long-term. Use cautiously in underweight patients. Use cautiously if taking heart medications or sedatives and if driving or operating heavy machinery. Use cautiously if pregnant or breastfeeding.
• Hypnosis : Several studies report on the use of hypnotherapy in people with nausea and vomiting related to cancer chemotherapy, pregnancy (hyperemesis gravidarum), and surgical recovery. Results are mixed and there is no reliable comparison to anti-nausea medications or other relaxation techniques. Better research is needed before a firm conclusion can be drawn.
• Use cautiously with mental illnesses, such as psychosis/schizophrenia, manic depression, multiple personality disorder, or dissociative disorders. Use cautiously with seizure disorders.
• Peppermint : Peppermint (Mentha x piperita), a perennial herb growing to the size of one meter and found throughout much of Europe and North America, has a long history of use for digestive disorders. More research is needed to determine if peppermint inhalation is an effective treatment for post-operative nausea.
• Avoid if allergic to peppermint oil or members of the Lamiaceae family. Avoid topical use of peppermint oil around the facial or chest areas of infants and young children, especially around the nose. Avoid injection of peppermint oil. Use cautiously in patients with gastroesophageal reflux disease, achlorhydria, G6PD deficiency, gallbladder disease, hiatal hernias, or kidney stones.
• TENS : Transcutaneous electrical nerve stimulation (TENS) is a non-invasive technique in which a low-voltage electrical current is delivered through wires from a small power unit to electrodes located on the skin. TENS is usually performed in conjunction with acupuncture treatments. Electrodes are temporarily attached with paste in various patterns, depending on the specific condition and treatment goals. Although limited available study found positive results when using TENS with post-operative nausea and vomiting, more research is needed. There is also not enough reliable evidence to draw a firm conclusion on the use of TENS for nausea and vomiting of pregnancy.
• Avoid with implantable devices, such as defibrillators, pacemakers, intravenous infusion pumps, or hepatic artery infusion pumps. Use cautiously with decreased sensation (such as neuropathy) or with seizure disorders. Avoid if pregnant or breastfeeding.

D Fair negative scientific evidence

• Acustimulation : Limited study suggests that using ReliefBand® to stimulate the P6 wrist point may not reduce gastroscopy-related nausea. Theoretically, future studies may contradict this finding, yet the nausea and retching is caused by the invasiveness of the procedure itself, rather than by internal factors in the patient, making it unlikely.
• Avoid if the cause of medical symptoms is unknown. Acustimulation devices may cause slight skin irritation under the electrodes when the wristband is used. Switch wrists to avoid. Acustimulation devices should only be used on the designated area. Use cautiously with pacemakers. Keep acustimulation devices out of the reach of children.

• Rest: Physical activity, even walking, may make nausea worse.
• Hydration: Staying hydrated is important when vomiting. Healthcare professionals recommend sucking on ice chips, taking small sips of water, weak tea, clear soft drinks (such as ginger ale, non-caffeinated sports drinks, or broth. Drinks containing sugar may calm the stomach better than other liquids. However, drinking too much liquid too quickly might worsen nausea and vomiting.
• Avoiding food odors: Healthcare professionals recommend avoiding strong food odors, such as cooking meats. It is best to avoid restaurants and other places likely to smell like food until the nausea and vomiting subside.
• Eating bland foods: Healthcare professionals recommend eating easily digested foods, such as gelatin, crackers, and toast. When the individual can keep these down, it is recommended to try cereal, rice, and fruit. It is best to avoid fatty or spicy foods, and wait to eat solid foods until about six hours after the last vomiting episode.
• Over-the-counter (OTC) motion sickness medicines: If an individual with motion sickness is planning a trip, OTC motion sickness drugs, such as dimenhydrinate (Dramamine®) or meclizine (Bonine®), may help calm a queasy stomach. For longer journeys, such as a cruise, a doctor can prescribe patches for motion sickness patches, such as scopolamine (Transderm Scop®). OTC medications for motion sickness may cause drowsiness, sedation, and dry mouth.