Vomiting - Causes and Symptoms

Definition

Vomiting is a phenomenon that consists in expelling the contents of the stomach and, sometimes, that present in the lower portion of the gastrointestinal tract through the mouth.

From a physiological point of view, vomiting is characterized by a complex sequence of events (vomiting reflex) coordinated by a center in the medulla oblongata. Most emetic stimuli originate from the gastrointestinal tract and the central nervous system.

Before vomiting, a person usually experiences a feeling of nausea, the skin becomes pale and increases the heart rate and sweating. Eventually, a series of deep breaths are followed by the closure of the glottis and the abdominal muscles energetically begin to contract.

The combination of these movements increases abdominal pressure and effectively compresses the stomach. The lower esophageal sphincter relaxes, allowing the gastric contents to enter the esophagus and, when the contractions become strong enough, this material is expelled from the mouth.

The substances that stimulate vomiting are called emetic . Compared to these, vomiting acts as a protective mechanism, which removes these substances from the gastrointestinal tract, before significant amounts of these can circulate.

Vomiting can be caused by a variety of stimuli, including a systemic illness (such as the flu), emotional states, intense pain, severe distention of the stomach or small intestine, rotational movement of the head (as in motion sickness) or ingestion of certain substances (such as copper sulfate, iron or ethanol).

Many episodes have an obvious cause, a benign physical examination and require exclusively symptomatic treatment.

In general, they are distinguished:

"Central" Vomiting : it is an emission of the "easy" and sudden gastrointestinal content, not preceded by nausea; it can have different causes: head trauma, migraine, ear diseases (Ménière's syndrome and labyrinthitis), metabolic dysfunction, intracranial hypertension (secondary to tumor or hemorrhage), meningitis and encephalitis.
Pregnancy vomiting : associated with nausea and occurs in the first trimester of pregnancy, especially in the morning or after food intake.
Obstructive vomiting : it is alimentary or bilious or fecaloid; it is the consequence of a partial or complete obstacle that prevents the progression of the gastroenteric contents (eg neoplasms, peptic ulcer, pyloric stenosis and intestinal obstruction).
Psychogenic vomiting : it is usually morning and watery; it can result from fatigue, stress conditions, strong emotions, excitement, fear, depression and other psychological disorders.
Reflected vomiting : it is the expression of various conditions, such as olfactory, unpleasant and intense stimuli, severe pain (eg intestinal or renal colic) and vasomotor headache. Furthermore, it is associated with motion sickness (malaise caused by cars, planes, boats, roller coasters and the like), respiratory diseases dominated by cough, myocardial infarction, gastroenteritis, hepatitis, appendicitis, cholecystitis and pancreatitis.
Toxic vomiting : it may derive from an exogenous cause (side effect or toxic effect of drugs, alcohol or toxin ingestion) or endogenous (toxic toxin, ketosis and uremia).

Other possible causes of vomiting include liver or kidney failure, diabetic ketoacidosis, exposure to radiation and advanced stages of cancer (regardless of chemotherapy or radiotherapy).

Characteristics and possible associated symptoms

Vomiting can be:

According to the content : food (different characters according to the digestive phase), biliary (emission of bile from yellow to dark green, based on the stagnation time), watery (acid, with gastric juices and little mucin), mucous (not acid and rich in mucin), haematic (bright red in case of hematemesis or caffean, if digested blood is present) and fecaloid (dark brown color and a typical faecal odor, due to prolonged stasis in the intestine).
According to taste : acid (from gastric hypersecretion), bitter (biliary) and repulsive (fecaloid, hematic).
Depending on the quantity : modest (central or psychogenic vomit) or abundant (from hypersecretion, from occlusion).

Usually, vomiting is preceded by nausea, conate (unsuccessful attempt to vomit, with closed glottis, which precedes the actual act) and hypersalivation. Important associated symptoms include abdominal pain, diarrhea or constipation, gas emission and headache and / or dizziness. The findings of particular concern include signs of hypovolemia (eg tachycardia and / or hypotension) and peritoneal signs; headache, neck stiffness or altered mental status (possible expression of endocranial pathologies); distended abdomen and tympanic. Sometimes, forced vomiting (of any cause) causes petechiae on the upper part of the trunk and face, similar to those found in meningitis.

Vomiting should be distinguished from regurgitation, ie the emission of undigested gastric contents, in the absence of nausea or contractions of the abdominal musculature. This occurs in patients with achalasia or Zenker diverticula.

Cyclic vomiting syndrome

Cyclic vomiting syndrome is a condition related to migraine, characterized by recurrent, severe and distinct attacks of vomiting or nausea. These episodes are interspersed with periods of well-being, in which patients do not show any obvious symptoms. Cyclic vomiting syndrome most commonly affects children between 3 months and 7 years and tends to regress into adulthood.

Cyclical vomiting is one of the "periodic syndromes of infancy possible common precursors of migraine" and is not attributed to gastrointestinal diseases.

The vomiting attacks are repeated at least 4 times per hour, for a period ranging from 1 hour to 5 days. The patient manifests an abundant salivation, a lot of thirst and resistance to speaking or swallowing. Other associated symptoms include pallor, intense prostration and lethargy. Cyclic vomiting syndrome generally limits itself after a few months or a few years.

Possible complications associated with vomiting

Vomiting can enter the airways and give phenomena "ab ingestis". If severe, it can lead to symptomatic dehydration and electrolyte alterations (typically a metabolic alkalosis with hypokalemia) or, rarely, of a laceration of the esophagus, both partial (Mallory-Weiss) and complete (Boerhaave syndrome). Chronic vomiting can cause hyponutrition, weight loss and metabolic changes.