What are the Causes of Nausea and Vomiting?

What are the Causes of Nausea and Vomiting?

Nausea and vomiting are consequences of various infections, medication intake, conditions affecting the digestive system and central nervous system, and metabolic and hormonal conditions.

Causes of Nausea and Vomiting are:

Infections: Infections of the digestive tract as well as infections in other parts of the body can result in nausea and vomiting.

• Food poisoning: Viral and bacterial infections of the digestive tract result in vomiting. Viruses like Adenovirus, Norwalk and Rotavirus and bacteria like staphylococcus cause gastroenteritis, where vomiting is often accompanied with loose motions. The patient also gives a history of eating out or eating stale food.
• Other infections: Besides gastroenteritis, infections outside the digestive tract like pneumonia, urinary tract infection, ear infection and peritonitis can also cause vomiting. The patient is usually febrile and shows other signs of infection. For example, a urinary tract infection may result in increased urination with burning; pneumonia may present with cough and sputum production.

Medications and Toxins: Nearly any medication can result in vomiting. Particularly notorious are chemotherapy medications and radiation treatment administered for the treatment of cancer. Other medications that commonly result in vomiting include antibiotics, digoxin and hormones. Besides medications, illicit drugs and toxins can also result in vomiting.

Digestive tract disorders: Besides food poisoning, other conditions that affect the digestive tract can also result in nausea and vomiting. These include:

• Motility disorders: The digestive tract shows movements, which direct the food downwards through the entire tract. Any abnormality in the motility of the esophagus or food pipe, stomach or intestines could result in motility disorders.
• Achalasia cardia: Achalasia cardia is a condition where the esophageal peristaltic movements in the lower part of the esophagus are absent and the tone of the lower esophageal sphincter is increased. The lower esophagus is thus dilated and the outlet is narrowed, which results in vomiting soon after eating food.
• Gastroparesis: Gastroparesis is a condition where the movements of the stomach are absent. The abdomen appears bloated, and the condition is accompanied by nausea and vomiting. Gastroparesis may affect diabetic patients or may occur after surgery as a complication.
• Paralytic Ileus: Paralytic ileus may follow conditions like infections, surgery, electrolyte abnormalities or decreased blood supply to the intestines. It may also occur due a mechanical cause like an obstruction. Abdominal fullness is usually present. The abdominal sounds may be decreased.

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• Obstruction: Any obstruction in the digestive tract results in vomiting. The type of vomitus, the timing of vomiting and the associated symptoms may give a clue to the diagnosis of the cause of obstruction.
• Esophageal obstruction: Esophageal obstruction could occur due to strictures, tumors or due to abnormalities at birth. Vomiting occurs soon after eating and consists of chewed and undigested food particles.
• Obstruction in the stomach: Some babies are born with a condition where the stomach outlet is blocked. This condition is called pyloric stenosis. The stomach appears enlarged after intake of milk or food. Pyloric stenosis could also affect adults and may be due to a tumor at the stomach outlet. The sound of fluid moving may be heard on shaking the abdomen; this finding is referred to as succession splash. The vomiting is usually projectile, that is, it is very forceful.
• Obstruction in the intestines: Obstruction in the intestines usually results in acute symptoms and severe pain. The abdomen is painful to touch and appears distended. Bowel sounds may be increased. A volvulus, which is the twisting of the intestines on itself, causes obstruction with nausea and vomiting especially in an infant. In addition, the child presents with bloody stools, pain, distention and constipation. In some cases, the vomitus may be greenish in color. In intussusception, a part of the intestine telescopes into another, resulting in obstruction, severe pain and vomiting. Cancers can also result in obstruction in the intestines. Strangulated hernias result in severe pain with vomiting.
• Inflammation: Inflammation of parts of the digestive tract can result in nausea and vomiting. The underlying condition can be diagnosed based on the associated clinical features. For example:
• Appendicitis results in nausea and vomiting and is associated with pain in the right lower side of the abdomen.
• Inflammation of the liver and/or gall bladder results in nausea and vomiting along with pain in the right upper part of the abdomen.
• Pancreatitis causes pain in the upper central part of the abdomen.

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Central Nervous System Causes: Conditions the affect the central nervous system that could result in vomiting include:

• Closed head injury: A closed head injury is a head injury that is not accompanied by a fracture of the skull. It may result in concussion of the brain and is accompanied by symptoms like nausea and vomiting, headache and confusion.
• Increased intracranial pressure: Conditions that increase the pressure within the skull like tumor, infarct, bleeding or an infection like meningitis, encephalitis or an abscess result in vomiting. The vomiting is associated with or without nausea.. The patients usually show the presence of neurological signs that point out to the cause of vomiting. An increase in intracranial pressure usually causes projectile vomiting.
• Migraine: Migraine typically causes nausea and vomiting. Other symptoms associated with migraine include an aura or premonition before the attack, which includes flashes of lights, and one-sided severe throbbing headache.
• Vestibular causes: Conditions affecting the inner ear may result in vomiting. These include labyrinthitis, Ménière’s disease and motion sickness. The nausea and vomiting in these conditions is usually associated with vertigo. Nystagmus or abnormal involuntary eye movements may be present.
• Psychiatric disorders: Psychiatric disorders like anxiety, depression and conversion disorder are often associated with nausea and vomiting. Anorexia nervosa is a condition where the patient induces vomiting in order to appear thin. Bulimia is another eating disorder where the patient experiences binges of eating and then vomits out the food. The fingers should be checked for calluses, which may indicate self-induced vomiting.

Hormonal and Metabolic Causes: Hormonal and metabolic causes that could result in nausea and vomiting are:

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• Pregnancy: Pregnancy is a common cause of vomiting in women of childbearing age. Nausea and vomiting are more common in the first three months of pregnancy and in the morning; it is therefore referred to as morning sickness. Some abnormal pregnancy conditions like hydatidiform mole are associated with excessive vomiting during pregnancy.
• Other hormonal conditions: Conditions resulting in hormonal problems like thyroid and parathyroid disorders as well as conditions affecting the adrenal gland can cause nausea and vomiting. The patient usually shows symptoms of the underlying condition.
• Diabetic ketoacidosis: Uncontrolled diabetes leads to accumulation of ketones in the blood, which results in vomiting. Blood sugar levels should be measured in a diabetic patient with vomiting.
• Uremia: Accumulation of urea in the body as a result of kidney failure results in nausea and vomiting. The patient also shows other signs of kidney failure like decreased urination and accumulation of fluid in the body.

Other Causes: Other causes of nausea and vomiting include:

• Acute glaucoma: Acute glaucoma is a condition where the eyeball pressure increases. The patient complains of a painful red eye along with nausea and vomiting.
• Acute myocardial infarction: A heart attack often presents with sudden chest pain along with nausea and vomiting.
• Intense pain: Any severely painful condition like kidney stones or severe headache can stimulate vomiting.