See also: Vomiting and antiemetic drugs
Generality
Vomiting, or emesis, consists in the forced expulsion of the gastric contents through the mouth. It is not a voluntary act, but a reflex event with a very specific physiological meaning; vomiting, in fact, is a defense aimed at removing substances - recognized as toxic - from the stomach, before they can be absorbed and harm the body.
As anticipated, vomiting is generally preceded by nausea (an urgent need to vomit) and so-called retching (spasmodic breathing movements).
Causes of Vomiting
See also: Vomiting - Causes and Symptoms
The morbid conditions in which the onset of this defensive reflex is observed are various and numerous, but all of them can be traced back to a stimulation of the bulbar center of vomiting. Multiple afferents arrive at this level, coming from various parts of the organism; this explains why the causes of vomiting are so diverse and numerous. The main ones have an indirect origin, such as acute or chronic diseases of the digestive system (gastritis, peptic ulcer, enteritis), gastric or intestinal stenosis and obstructions (in this case the onset of vomiting after a meal is the earlier the more high is the site of the occlusion), irritation of the peritoneum (appendicitis, peritonitis, acute pancreatic necrosis), occlusions of the excretory or biliary tract, stimulation of the vestibular nerve and motion sickness (as occurs in car, air or nautical travel), violent pain, ingestion of spoiled food or large quantities of liquids or food, prolonged fasting, infectious / febrile states in children, some drugs, strong sensory stimuli (a particularly pungent odor, a somewhat disgusting taste, etc.), radio and chemotherapy, pregnancy (especially in the first months), metabolic and / or disendocrine alterations (diabetes, uremia, hyperparathyroidism, ketoacidosis, Addison's disease) and emotional factors. The bulbar center of vomiting can also be stimulated directly, as happens - for example - in all those situations that increase intracranial pressure (brain tumors and hemorrhages, head trauma, etc.), in psychosis, in "exposure to a" excessive heat or following the intake of drugs that act directly on it, such as apomorphine and digitalis.
Mechanism of vomiting
The vomiting center, in addition to receiving numerous afferents, is also capable of sending multiple signals to allow the expulsion of the gastric contents. Taken together, these impulses close the glottis and raise the soft palate (to prevent the entry of vomit in the respiratory tract which, when it occurs, can cause aspiration pneumonia) and the pylorus (which joins the stomach to the intestine); decrease the tone of the cardia (the valve that unites the esophagus and stomach); fix the diaphragm in the inspiratory position (with increase in intra-abdominal pressure); finally, with the collaboration of the intercostal, diaphragmatic and abdominal muscles, they trigger movements of reverse peristalsis that make the contents of the stomach flow back to the mouth (vomiting).
When to worry and see a doctor immediately?
Often the appearance of vomiting makes us regret a "binge with friends, having gulped food that is difficult to digest, or having gone out with too light clothes. Sporadic episodes, symptoms of a mild and transient discomfort, should not worry the patient excessively. ; different speech in all those cases in which vomiting arises systematically, appears in conjunction with a well-known pathology or severe symptoms of another nature (high fever, severe abdominal pain, yellow color of the skin), takes on a particularly expressive color (vomiting blood or biliary, therefore red-black yellow-greenish) or a nauseating odor (fecaloid vomiting), or when several episodes are repeated over a short period of time. In the latter case, especially if associated with diarrhea, vomiting becomes dangerous - especially for children - because it causes severe dehydration. The impossibility of undertaking oral rehydration therapy requires, in some cases, an intravenous infusion of physiological saline. The cause of the simultaneous presence of vomiting and diarrhea is often represented by acute gastroenteritis (intestinal flu).
Treatment and therapy of vomiting
See also: Vomiting - Medicines to Treat Vomiting
In addition to treating any dehydration, vomiting must be treated, in the first instance, by identifying and appropriately treating the disease or condition that caused it. If it has iatrogenic origins (it is caused by drugs), for example, it is generally sufficient to stop the treatment or adopt an alternative one; in other cases, when vomiting is the consequence of neurosis, psychotherapy is recommended to eliminate excess anxiety, irascibility and emotionality (also anxiolytic-sedative drugs can be useful). Particular attention in pregnancy, during which many drugs (including most antiemetics) are contraindicated for the possible damage they could cause to the fetus; remedies to counter the nausea that often accompanies this magical period are listed in this article.
In the presence of vomiting, herbal medicine relies on the anti-emetic virtues of ginger (especially effective in pregnancy), to be taken in doses of 1-3 grams per day.
Read also: Remedies for Vomiting »
