Nausea is a peculiar sensation of discomfort in the epigastrium, behind the sternum, in the throat and oral cavity, which is often a harbinger of vomiting. May be accompanied by salivation, hyperhidrosis, weakness, dizziness. It is extremely rarely observed in healthy people with diet errors. Usually appears in diseases of the digestive organs and the central nervous system, intoxication conditions. To clarify the causes of nausea, endoscopic, radiological, ultrasound, electrophysiological and laboratory research methods are used. Before the diagnosis is made, sedative herbal remedies, prokinetics, and enterosorbents are usually used to reduce the severity of the symptom.
general characteristics
Patients characterize nausea as a painful sensation in the mouth, throat, along the esophagus, in the epigastrium, accompanied by a desire to induce vomiting or an urge to vomit. In addition to discomfort in the digestive tract, abundant salivation, an unusual taste in the mouth, cold extremities, sweating, hyperhidrosis of the palms and feet are often noted. Characterized by weakness, dizziness, darkening of the eyes, unsteady gait. Epigastric constriction may be felt. From the side, patients look confused, insecure, pale, sweaty. In some cases, the connection of nausea with food is revealed.
With food errors, mild poisoning, a number of gastroenterological diseases, the patient's condition may improve spontaneously or after vomiting. Constant nausea lasting longer than two days is an indication for consulting a gastroenterologist or therapist. The combination of nausea with thoracic, abdominal and headache, vomiting of blood or masses of the color of coffee grounds, black tarry stools, hyperthermia over 38 ° C, convulsions, lack of urine, confusion is sufficient reason to seek emergency medical help.
Development mechanism
At the heart of the occurrence of nausea is the activation of the nervous arc of the gag reflex at a level insufficient for the onset of vomiting. The most common starting point for a reflex reaction is irritation of peripheral receptors located in the digestive and a number of other organs. Less commonly, the reflex is activated due to excitation of the vomiting center, exposure to toxic substances or metabolites on the receptive zone of the bottom of the fourth ventricle of the brain. In a number of conditions (for example, pregnancy), a combination of several triggering factors is possible.
Regardless of the reasons that provoked the development of nausea, the mechanism of its formation is based on a single pathophysiological process. When the vomiting center is activated, the tone of the muscular membrane of the stomach decreases, its peristalsis slows down or completely stops. A simultaneous increase in the tone of the duodenum and the proximal part of the jejunum causes duodenogastric reflux. An increase in the volume of gastric chyme leads to reflex relaxation of the cardia, contraction of the antrum, diaphragm and intercostal muscles, which is perceived as an urge to vomit.
Classification
When systematizing the forms of nausea, its duration, features of the onset and mechanism of development are taken into account. According to the duration of discomfort, episodic and permanent forms of the disorder are distinguished. Episodic nausea usually comes on suddenly and may or may not be food related. More often it appears with errors in nutrition, poisoning, and other acute conditions. Constant nausea of varying intensity is more characteristic of CNS damage and chronic diseases. Depending on the pathogenesis, the following symptoms are distinguished:
- Central (cerebral) nausea . Based on the excitation of the vomiting center in the pathology of the nervous system. It is observed with inflammatory or tumor damage to the substance and membranes of the brain, craniocerebral injuries, hypertensive crises. May occur suddenly or disturb the patient for a long time. After vomiting, the condition, as a rule, does not improve, but often intensifies.
- Toxic nausea . Associated with the activation of the vomiting center due to exo- and endotoxin irritation of the chemoreceptor zone in the bottom of the IV ventricle. It is noted in case of poisoning with drugs, poisonous products and substances, toxic metabolites in liver and kidney failure, radiation sickness, ketoacidosis in patients with diabetes mellitus. The intensity of the symptom depends on the severity of intoxication.
- Reflex nausea . Caused by irritation of the receptor apparatus of the nervous chain of the gag reflex. Nerve endings that stimulate the appearance of nausea are located in the root of the tongue, the back of the pharynx, stomach, ileocecal zone, intestines, pancreas, hepatobiliary system, peritoneum, inner ear and other organs. It is most often associated with food intake and manifests itself in the structure of gastrointestinal diseases.
- Vestibular (motor) nausea . It is provoked by a change in body position, direction or speed of movement with irritation of the vestibular apparatus and excitation of the vomiting center. In a healthy person, it occurs in the form of motion sickness when driving a car or rotating movements of the body. It is characteristic of brain pathology with damage to the inner ear, cerebellopontine angle and vestibular stem nuclei.
- Psychogenic nausea . It is observed during the implementation of a firmly fixed conditioned reflex. Nausea is triggered by olfactory and visual sensations that cause disgust or unpleasant emotions. It often manifests itself in neurotic and neurosis-like states, psychogenies, overwork, conflicts. It can serve as a somatoform manifestation of depression, psychotic disorders.
- Exchange nausea . It develops due to violations of the physiological transformation of nutrients against the background of vitamin, mineral, endocrine deficiency. Probably, it is realized through the influence of metabolites on the receptor zone of the medulla oblongata and activation of nerve endings against the background of a secondary gastrointestinal tract lesion. It is detected in patients with hypothyroidism, hyperfunction of the parathyroid glands, premenstrual syndrome, etc.
Causes of nausea
Causes of nausea after eating
In some patients, food-related nausea is physiological in origin and is caused by overeating, dietary errors, changes during pregnancy. Pathological causes of nausea after eating are:
- Diseases of the stomach : acute gastritis, atony, neoplasms.
- Food allergy .
- Intoxication of the body : food poisoning, poisoning with plant poisons, an overdose of medicines.
- Diseases of the pancreato-duodenal zone : duodeno-gastric reflux, duodenostasis, chronic pancreatitis (including alcohol).
- Pathology of the hepatobiliary system : chronic cholecystitis and cholangitis, biliary dyskinesia, liver echinococcosis.
- Infectious processes : rotavirus and norovirus infections, escherichiosis, salmonellosis.
- Complications after surgical interventions : dumping syndrome, postcholecystectomy syndrome.
Causes of nausea on an empty stomach
A healthy person may experience nausea on an empty stomach when taking certain medications (vitamins, iron preparations) before meals. In most cases, the appearance of a symptom indicates damage to the gastrointestinal tract, less often - about other pathological conditions. Causes of nausea on an empty stomach are:
- Gastrointestinal diseases : erosion of the esophagus, gastritis and peptic ulcer, irritable stomach syndrome.
- Parasitic invasions : giardiasis, toxoplasmosis, ascariasis.
- Endogenous poisoning : uremia, chronic renal failure, cancer intoxication.
- Migraine .
- Early toxicosis during pregnancy .
- Emergency conditions : hypertensive crisis, acute abdomen syndrome (appendicitis, peritonitis).
Causes of nausea during pregnancy
Nausea is one of the most common symptoms that pregnant women experience. Usually it is explained by a complex restructuring of the body for bearing a child, but it can also have pathological causes. Nausea during pregnancy is caused by:
- Physiological prerequisites : overeating, growth of the uterus, delayed defecation.
- early toxicosis.
- Pathologies of pregnancy : preeclampsia and eclampsia, hyperthyroidism of pregnant women, polyhydramnios, cholestasis.
- Concomitant diseases of the gastrointestinal tract : GERD, chronic gastritis and pancreatitis, dysbacteriosis.
- Ovarian hyperstimulation syndrome .
Diagnostics
Patients with complaints of nausea are initially referred to a specialist gastroenterologist. The doctor conducts a comprehensive examination of the digestive system to identify structural and functional disorders, which are most often accompanied by nausea. To establish the cause of nausea, laboratory and instrumental studies are used, the most informative of which are:
- Ultrasonic method . Ultrasound of the abdominal organs is a non-invasive and safe study that can be prescribed to all patients, including pregnant women. With the help of sonography, the doctor detects organic causes from the gastrointestinal tract and the biliary system: thickening or deformation of the walls of organs, volumetric formations.
- X-ray examination . Nausea is a common symptom of diseases of the esophagus and duodeno-gastric zone, for the detection of which X-ray with contrasting barium suspension is used. To assess the patency of the digestive tract and the rate of passage of chyme, a series of delayed x-rays is performed.
- Endoscopic examination . With the help of endoscopy, the state of the upper gastrointestinal tract is visually assessed: the mucous membrane is examined, signs of inflammation and destruction are revealed, and a biopsy of altered tissue areas is performed. If reflux is suspected, the method is supplemented by daily pH-metry inside the stomach and lower part of the esophagus.
- The study of feces . The coprogram is carried out to detect characteristic signs of gastrointestinal pathologies, which are manifested by nausea. In the presence of symptoms of an intestinal infection, as a cause of nausea, bacteriological culture of feces is recommended to detect microorganisms. Additionally, the level of fecal elastase is determined.
- Laboratory tests . To clarify the diagnosis, a biochemical study of blood with liver tests, an assessment of the levels of acute phase indicators are shown. With the help of serological reactions, causative agents of intestinal infections are identified, helicobacteriosis is detected. The method is supplemented with specific breath tests.
In case of difficulties in diagnosis, CT or MRI of the abdominal cavity, duodenal sounding with bacteriological culture of bile are performed. Sometimes allergy tests are carried out with the most common allergens. Women who complain of nausea must be referred for a consultation with a gynecologist. After exclusion of gastroenterological pathology, a comprehensive neurological examination and consultations of other specialists are indicated.
Various medications are used to relieve nausea.
Treatment
Help before diagnosis
To reduce the intensity of nausea, it is recommended to drink ginger or mint tea, slowly eat a slice of lemon. It is better to eat food in small portions, avoid smoked meats and spicy foods, carbonated drinks and fast food. After eating, it is undesirable to occupy a horizontal position. People prone to allergies should limit their consumption of strawberries, peanuts, and citrus fruits as much as possible. Severe prolonged nausea, which makes it difficult to eat and is accompanied by vomiting, is the basis for contacting a gastroenterologist.
Conservative therapy
The treatment regimen is selected individually, after identifying the cause of nausea. In addition to medicines, diet therapy, psychotherapy methods are used, which are especially effective for functional digestive disorders in pregnant women. Etiotropic and pathogenetic therapy is aimed at eliminating the cause of the underlying disease and individual links in the mechanism of its development, and drugs are also prescribed to relieve unpleasant symptoms. The most commonly used groups of pharmaceuticals are:
- Sedative herbal remedies . With moderate nausea, herbal medicines (valerian, motherwort) help, which normalize the autonomic nervous regulation of the digestive tract. Sometimes combined medicines, bromides are used.
- Antihistamines . These drugs are good at relieving nausea, the causes of which are associated with an allergic reaction to food. In case of systemic allergies, short courses of glucocorticosteroid hormones are additionally prescribed.
- Prokinetics . Medicines stimulate the peristalsis of the digestive tract, normalize the tone of the esophageal and gastric sphincters. To eliminate nausea, prokinetics are often combined with enterosorbents.
- Antisecretory agents . Proton pump inhibitors and H2 receptor blockers are indicated for nausea caused by increased stomach acid. High efficiency has a new class of drugs - prostaglandins.
- Serotonin receptor antagonists . Medicines have a strong effect, because they directly affect receptors in the brain. Recommended for nausea, which is not stopped by other means.
- Antibacterial drugs . Medicines of this group are used in cases where nausea is caused by intestinal infections. With parasitic infestations, anthelmintic and antiprotozoal drugs are indicated.