Nausea | |
---|---|
A 1681 painting depicting a person vomiting | |
Specialty | Gastroenterology |
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. [1] It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. [2]
Over 30 definitions of nausea were proposed in a 2011 book on the topic. [3]
Nausea is a non-specific symptom, which means that it has many possible causes. Some common causes of nausea are gastroenteritis and other gastrointestinal disorders, food poisoning, motion sickness, dizziness, migraine, fainting, low blood sugar, anxiety, hyperthermia, dehydration and lack of sleep. Nausea is a side effect of many medications including chemotherapy, or morning sickness in early pregnancy. Nausea may also be caused by disgust and depression. [1]
Medications taken to prevent and treat nausea and vomiting are called antiemetics. The most commonly prescribed antiemetics in the US are promethazine, metoclopramide, and the newer ondansetron. The word nausea is from Latin nausea, from Greek ναυσία – nausia, [4] "ναυτία" – nautia, motion sickness, "feeling sick or queasy". [5]
Gastrointestinal infections (37%) and food poisoning are the two most common causes of acute nausea and vomiting. [1] Side effects from medications (3%) and pregnancy are also relatively frequent. [1] There are many causes of chronic nausea. [1] Nausea and vomiting remain undiagnosed in 10% of the cases. Aside from morning sickness, there are no sex differences in complaints of nausea. After childhood, doctor consultations decrease steadily with age. Only a fraction of one percent of doctor visits by those over 65 are due to nausea. [6]
Gastrointestinal infection is one of the most common causes of acute nausea and vomiting. [1] Chronic nausea may be the presentation of many gastrointestinal disorders, occasionally as the major symptom, such as gastroesophageal reflux disease, functional dyspepsia, gastritis, biliary reflux, gastroparesis, peptic ulcer, celiac disease, non-celiac gluten sensitivity, Crohn's disease, hepatitis, upper gastrointestinal malignancy, and pancreatic cancer. [1] [7] Uncomplicated Helicobacter pylori infection does not cause chronic nausea. [1]
Food poisoning usually causes an abrupt onset of nausea and vomiting one to six hours after ingestion of contaminated food and lasts for one to two days. [8] It is due to toxins produced by bacteria in food. [8]
Many medications can potentially cause nausea. [8] Some of the most frequently associated include cytotoxic chemotherapy regimens for cancer and other diseases, and general anaesthetic agents. An old cure for migraine, ergotamine, is well known to cause devastating nausea in some patients; a person using it for the first time will be prescribed an antiemetic for relief if needed.[ citation needed ]
Nausea or "morning sickness" is common during early pregnancy but may occasionally continue into the second and third trimesters. In the first trimester nearly 80 % of women have some degree of nausea. [9] Pregnancy should therefore be considered as a possible cause of nausea in any sexually active woman of child-bearing age. [8] While usually it is mild and self-limiting, severe cases known as hyperemesis gravidarum may require treatment. [10]
A number of conditions involving balance such as motion sickness and vertigo can lead to nausea and vomiting. [11]
Dysmenorrhea can cause nausea. [12]
Nausea may be caused by depression, anxiety disorders and eating disorders. [13]
While most causes of nausea are not serious, some serious conditions are associated with nausea. These include pancreatitis, small bowel obstruction, appendicitis, cholecystitis, hepatitis, Addisonian crisis, diabetic ketoacidosis, increased intracranial pressure, spontaneous intracranial hypotension, brain tumors, meningitis, heart attack, rabies, [14] carbon monoxide poisoning and many others. [1]
Obstructing disorders
Enteric infections
Inflammatory diseases
Sensorimotor dysfunction
Other
Cardiopulmonary
Inner-ear diseases
Intracerebral disorders
Psychiatric illnesses
Other
Drugs
Endocrine/metabolic disease
Toxins
Research on nausea and vomiting has relied on using animal models to mimic the anatomy and neuropharmacologic features of the human body. [16] The physiologic mechanism of nausea is a complex process that has yet to be fully elucidated. There are four general pathways that are activated by specific triggers in the human body that go on to create the sensation of nausea and vomiting. [17]
Signals from any of these pathways then travel to the brainstem, activating several structures including the nucleus of the solitary tract, the dorsal motor nucleus of the vagus, and central pattern generator. [18] These structures go on to signal various downstream effects of nausea and vomiting. The body's motor muscle responses involve halting the muscles of the gastrointestinal tract, and in fact causing reversed propulsion of gastric contents towards the mouth while increasing abdominal muscle contraction. Autonomic effects involve increased salivation and the sensation of feeling faint that often occurs with nausea and vomiting.
It has been described that alterations in heart rate can occur as well as the release of vasopressin from the posterior pituitary. [3]
Taking a thorough patient history may reveal important clues to the cause of nausea and vomiting. If the patient's symptoms have an acute onset, then drugs, toxins, and infections are likely. In contrast, a long-standing history of nausea will point towards a chronic illness as the culprit. The timing of nausea and vomiting after eating food is an important factor to pay attention to. Symptoms that occur within an hour of eating may indicate an obstruction proximal to the small intestine, such as gastroparesis or pyloric stenosis. An obstruction further down in the intestine or colon will cause delayed vomiting. An infectious cause of nausea and vomiting such as gastroenteritis may present several hours to days after the food was ingested. [15] The contents of the emesis is a valuable clue towards determining the cause. Bits of fecal matter in the emesis indicate obstruction in the distal intestine or the colon. Emesis that is of a bilious nature (greenish in color) localizes the obstruction to a point past the stomach. Emesis of undigested food points to an obstruction prior to the gastric outlet, such as achalasia or Zenker's diverticulum. If patient experiences reduced abdominal pain after vomiting, then obstruction is a likely etiology. However, vomiting does not relieve the pain brought on by pancreatitis or cholecystitis. [15]
It is important to watch out for signs of dehydration, such as orthostatic hypotension and loss of skin turgor. Auscultation of the abdomen can produce several clues to the cause of nausea and vomiting. A high-pitched tinkling sound indicates possible bowel obstruction, while a splashing "succussion" sound is more indicative of gastric outlet obstruction. Eliciting pain on the abdominal exam when pressing on the patient may indicate an inflammatory process. Signs such as papilledema, visual field losses, or focal neurological deficits are red flag signs for elevated intracranial pressure. [15]
When a history and physical exam are not enough to determine the cause of nausea and vomiting, certain diagnostic tests may prove useful. A chemistry panel would be useful for electrolyte and metabolic abnormalities. [19] Liver function tests and lipase would identify pancreaticobiliary diseases. [19] Abdominal X-rays showing air-fluid levels indicate bowel obstruction, while an X-ray showing air-filled bowel loops are more indicative of ileus. More advanced imaging and procedures may be necessary, such as a CT scan, upper endoscopy, colonoscopy, barium enema, or MRI. Abnormal GI motility can be assessed using specific tests like gastric scintigraphy, wireless motility capsules, and small-intestinal manometry. [15]
If dehydration is present due to loss of fluids from severe vomiting, rehydration with oral electrolyte solutions is preferred. [1] If this is not effective or possible, intravenous rehydration may be required. [1] Medical care is recommended if: a person cannot keep any liquids down, has symptoms more than 2 days, is weak, has a fever, has stomach pain, vomits more than two times in a day or does not urinate for more than 8 hours. [20]
Numerous pharmacologic medications are available for the treatment of nausea. There is no medication that is clearly superior to other medications for all cases of nausea. [21] The choice of antiemetic medication may be based on the situation during which the person experiences nausea. For people with motion sickness and vertigo, antihistamines and anticholinergics such as meclizine and scopolamine are particularly effective. [22] Nausea and vomiting associated with migraine headaches respond best to dopamine antagonists such as metoclopramide, prochlorperazine, and chlorpromazine. [22] In cases of gastroenteritis, serotonin antagonists such as ondansetron were found to suppress nausea and vomiting, as well as reduce the need for IV fluid resuscitation. [22] The combination of pyridoxine and doxylamine is the first line treatment for pregnancy-related nausea and vomiting. [22] Dimenhydrinate is an inexpensive and effective over the counter medication for preventing postoperative nausea and vomiting. [23] Other factors to consider when choosing an antiemetic medication include the person's preference, side-effect profile, and cost.
Nabilone is also indicated for this purpose.
In certain people, cannabinoids may be effective in reducing chemotherapy associated nausea and vomiting. [24] [25] Several studies have demonstrated the therapeutic effects of cannabinoids for nausea and vomiting in the advanced stages of illnesses such as cancer and AIDS. [26] [27]
In hospital settings topical anti-nausea gels are not indicated because of lack of research backing their efficacy. [28] Topical gels containing lorazepam, diphenhydramine, and haloperidol are sometimes used for nausea but are not equivalent to more established therapies. [28]
Ginger has also been shown to be potentially effective in treating several types of nausea. [29] [30]
The outlook depends on the cause. Most people recover within few hours or a day. While short-term nausea and vomiting are generally harmless, they may sometimes indicate a more serious condition. When associated with prolonged vomiting, it may lead to dehydration or dangerous electrolyte imbalances or both. Repeated intentional vomiting, characteristic of bulimia, can cause stomach acid to wear away at the enamel present on the teeth. [31]
Nausea and or vomiting is the main complaint in 1.6% of visits to family physicians in Australia. [6] However, only 25% of people with nausea visit their family physician. [1] In Australia, nausea, as opposed to vomiting, occurs most frequently in persons aged 15–24 years, and is less common in other age groups. [6]
Gastroenterology is the branch of medicine focused on the digestive system and its disorders. The digestive system consists of the gastrointestinal tract, sometimes referred to as the GI tract, which includes the esophagus, stomach, small intestine and large intestine as well as the accessory organs of digestion which include the pancreas, gallbladder, and liver.
An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer. They may be used for severe cases of gastroenteritis, especially if the patient is dehydrated.
Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement. Complications from constipation may include hemorrhoids, anal fissure or fecal impaction. The normal frequency of bowel movements in adults is between three per day and three per week. Babies often have three to four bowel movements per day while young children typically have two to three per day.
Metoclopramide is a medication used for stomach and esophageal problems. It is commonly used to treat and prevent nausea and vomiting, to help with emptying of the stomach in people with delayed stomach emptying, and to help with gastroesophageal reflux disease. It is also used to treat migraine headaches.
Coffee ground vomitus refers to a particular appearance of vomit. Within organic heme molecules of red blood cells is the element iron, which oxidizes following exposure to gastric acid. This reaction causes the vomitus to look like ground coffee.
Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Since the abdomen contains most of the body's vital organs, it can be an indicator of a wide variety of diseases. Given that, approaching the examination of a person and planning of a differential diagnosis is extremely important.
Gastrointestinal diseases refer to diseases involving the gastrointestinal tract, namely the esophagus, stomach, small intestine, large intestine and rectum; and the accessory organs of digestion, the liver, gallbladder, and pancreas.
The chemoreceptor trigger zone (CTZ) is an area of the medulla oblongata that receives inputs from blood-borne drugs or hormones, and communicates with other structures in the vomiting center to initiate vomiting. The CTZ is located within the area postrema, which is on the floor of the fourth ventricle and is outside of the blood–brain barrier. It is also part of the vomiting center itself. The neurotransmitters implicated in the control of nausea and vomiting include acetylcholine, dopamine, histamine, substance P, and serotonin. There are also opioid receptors present, which may be involved in the mechanism by which opiates cause nausea and vomiting. The blood–brain barrier is not as developed here; therefore, drugs such as dopamine which cannot normally enter the CNS may still stimulate the CTZ.
Hyperemesis gravidarum (HG) is a pregnancy complication that is characterized by severe nausea, vomiting, weight loss, and possibly dehydration. Feeling faint may also occur. It is considered more severe than morning sickness. Symptoms often get better after the 20th week of pregnancy but may last the entire pregnancy duration.
Abdominal distension occurs when substances, such as air (gas) or fluid, accumulate in the abdomen causing its expansion. It is typically a symptom of an underlying disease or dysfunction in the body, rather than an illness in its own right. People with this condition often describe it as "feeling bloated". Affected people often experience a sensation of fullness, abdominal pressure, and sometimes nausea, pain, or cramping. In the most extreme cases, upward pressure on the diaphragm and lungs can also cause shortness of breath. Through a variety of causes, bloating is most commonly due to buildup of gas in the stomach, small intestine, or colon. The pressure sensation is often relieved, or at least lessened, by belching or flatulence. Medications that settle gas in the stomach and intestines are also commonly used to treat the discomfort and lessen the abdominal distension.
Intestinal pseudo-obstruction (IPO) is a clinical syndrome caused by severe impairment in the ability of the intestines to push food through. It is characterized by the signs and symptoms of intestinal obstruction without any lesion in the intestinal lumen. Clinical features mimic those seen with mechanical intestinal obstructions and can include abdominal pain, nausea, abdominal distension, vomiting, dysphagia and constipation depending upon the part of the gastrointestinal tract involved.
Chronic intestinal pseudo-obstruction (CIPO) is an uncommon syndrome with chronic and recurrent symptoms that suggest intestinal obstruction in the absence of any mechanical blockage of the lumen. The most common symptoms of CIPO include abdominal pain, constipation, nausea, vomiting, dysphagia, and abdominal distention. CIPO can lead to malnutrition.
Abdominal angina is abdominal pain after eating caused by a reduction of blood flow to the celiac trunk, superior mesenteric arteries (SMA), inferior mesenteric artery (IMA), or the surrounding organs. Symptoms include abdominal pain, weight loss, diarrhea, nausea, vomiting, and an aversion or fear of eating caused by the pain associated with eating.
Vomiting is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.
Mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE) is a rare autosomal recessive mitochondrial disease. It has been previously referred to as polyneuropathy, ophthalmoplegia, leukoencephalopathy, and intestinal pseudoobstruction. The disease presents in childhood, but often goes unnoticed for decades. Unlike typical mitochondrial diseases caused by mitochondrial DNA (mtDNA) mutations, MNGIE is caused by mutations in the TYMP gene, which encodes the enzyme thymidine phosphorylase. Mutations in this gene result in impaired mitochondrial function, leading to intestinal symptoms as well as neuro-ophthalmologic abnormalities. A secondary form of MNGIE, called MNGIE without leukoencephalopathy, can be caused by mutations in the POLG gene.
The 5-HT3 antagonists, informally known as "setrons", are a class of drugs that act as receptor antagonists at the 5-HT3 receptor, a subtype of serotonin receptor found in terminals of the vagus nerve and in certain areas of the brain. With the notable exceptions of alosetron and cilansetron, which are used in the treatment of irritable bowel syndrome, all 5-HT3 antagonists are antiemetics, used in the prevention and treatment of nausea and vomiting. They are particularly effective in controlling the nausea and vomiting produced by cancer chemotherapy and are considered the gold standard for this purpose.
Gastroparesis is a medical disorder of ineffective neuromuscular contractions (peristalsis) of the stomach, resulting in food and liquid remaining in the stomach for a prolonged period of time. Stomach contents thus exit more slowly into the duodenum of the digestive tract, a medical sign called delayed gastric emptying. The opposite of this, where stomach contents exit quickly into the duodenum, is called dumping syndrome.
Metopimazine, sold under the brand names Vogalen and Vogalene, is an antiemetic of the phenothiazine group which is used to treat nausea and vomiting. It is marketed in Europe, Canada, and South America. As of August 2020, metopimazine has been repurposed and is additionally under development for use in the United States for the treatment of gastroparesis.
Chemotherapy-induced nausea and vomiting (CINV) is a common side-effect of many cancer treatments. Nausea and vomiting are two of the most feared cancer treatment-related side effects for cancer patients and their families. In 1983, Coates et al. found that patients receiving chemotherapy ranked nausea and vomiting as the first and second most severe side effects, respectively. Up to 20% of patients receiving highly emetogenic agents in this era postponed, or even refused, potentially curative treatments. Since the 1990s, several novel classes of antiemetics have been developed and commercialized, becoming a nearly universal standard in chemotherapy regimens, and helping to better manage these symptoms in a large portion of patients. Efficient mediation of these unpleasant and sometimes debilitating symptoms results in increased quality of life for the patient, and better overall health of the patient, and, due to better patient tolerance, more effective treatment cycles.
Cancer and nausea are associated in about fifty percent of people affected by cancer. This may be as a result of the cancer itself, or as an effect of the treatment such as chemotherapy, radiation therapy, or other medication such as opiates used for pain relief. About 70–80% of people undergoing chemotherapy experience nausea or vomiting. Nausea and vomiting may also occur in people not receiving treatment, often as a result of the disease involving the gastrointestinal tract, electrolyte imbalance, or as a result of anxiety. Nausea and vomiting may be experienced as the most unpleasant side effects of cytotoxic drugs and may result in patients delaying or refusing further radiotherapy or chemotherapy.
A lower proportion of NCG/WS patients (from 30% to 50%) complain of upper gastrointestinal tract manifestations, e.g. vomiting, nausea, gastroesophageal reflux disease, aerophagia and aphthous stomatitis. (NCG/WS: Non-coeliac gluten/wheat sensitivity)