Nausea is a subjective symptom  disorders that also cause vomiting.

• Vomiting can result from the stimulation of  four neurologic
• processes of Nausea and Vomiting — vagal and splanchnic fibers in the viscera, stimulated by distention,infection,or  inflammatory irritation,   vestibular system fibers mediated through muscarinic cholinergic and histamine H1 receptors, sounds, or emotions ,higher central nervous system (CNS) centers where sights,  can trigger vomiting, .
• In brain their are chemoreceptor trigger zone within the brain that is rich in opioid, serotonergic, and dopamine receptors triggered by toxins, hypoxia, acidosis, radiation therapy, uremia, and chemotherapy

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Nausea and Vomiting General Description —

• Vomiting is the active and forceful expulsion of gastric contents,
• Nausea is a “vague, intensely disagreeable sensation of sickness or â˜queasinessâ that may or may not be followed by vomiting and is distinguished from anorexiaâ€� €€== .
• A subjective unpleasant, wavelike sensation in the back of the throat, epigastrium, or abdomen that may or may not lead to the urge or need to vomit

Nausea and Vomiting Types –

cyclic vomiting:

• Periodic and recurring attacks of vomiting occurring in patients with a nervous temperament.
• Continued vomiting causes metabolic alkalosis as a result of chloride loss.

epidemic vomiting:

• Sudden unexplained attacks of gastroenteritis characterized by nausea, vomiting, and sometimes diarrhea.
• Although not proven, the symptoms are believed to be due to a virus. Treatment is symptomatic.

induced vomiting:

• The production of vomiting by administering certain types of emetics (e.g., syrup of ipecac or amorphine) or by physical stimulation of the posterior pharynx.

psychogenic vomiting:

• Each person has the potential for this reaction to emotional stress, but the threshold varies from one person to another
• Occasional or persistent vomiting associated with severe emotional stress or brought on by the anticipation of stress.

vomiting of pregnancy

• The vomiting, esp. morning sickness, that some women experience during pregnancy.

Pathophysiology and Etiology with Epidemiology —

• A thorough history should discuss sleep habits€€, the onset and frequency of vomiting, the symptoms of other family members, and the relationship to nausea and vomiting to meals or€€ types of food.

• A review of systems should specifically address associated anorexia, weight loss, abdominal pain, gastrointestinal €€symptoms, and neurologic symptoms€€. Vomiting prior to breakfast is more common in pregnancy, uremia,alcohol overuse,  and increased intracranial pressure .
• Vomiting of undigested food one or more hours after meals should raise concern for gastric outlet obstruction or gastroparesis, whereas vomiting immediately after a meal is more common with psychogenic vomiting and bulimia.
• Many medications can induce nausea   vomiting, including nonsteroidal anti-inflammatory drugs, opiates, anticonvulsants, antiparkinsonian agents,antibiotics, calcium channel blockers,  nicotine,  antiarrhythmics, alcohol, Beta-blockers, digoxin, chemotherapeutic agents

• The abdominal exam should attempt to localize pain
• The physical examination should evaluate for acute dehydration and signs of infection.
• and evaluate for peptic ulcer disease, gallbladder disease, liver disease, or an acute abdomen.

Testing —

• Barium radiography, an upper GI series, or abdominal computed tomography may be helpful in the diagnosis of gastric outlet obstruction  gastroparesis .
• In severe acute or persistent vomiting, a flat and upright abdominal radiograph can help rule out GI obstruction or a perforated viscous.

• Concerns for intracranial lesions should prompt computed tomography or magnetic resonance imaging of the brain.
• Based on the clinical assessment, blood tests, liver function,hepatitis testing, amylase , pregnancy testing,  or a metabolic profile may be appropriate. €€ For acute gastroenteritis that is not complicated by dehydration, laboratory tests are not necessary.

• The diagnosis of acute nausea and vomiting can often be made on clinical history alone €€ Chronic symptoms may be more difficult to diagnose and may require laboratory and diagnostic testing. lists the differential diagnosis of nausea and vomiting.

Clinical manifestations Nausea and Vomiting

• Most patients with nausea and vomiting do not seek medical consultation and their disease is self-limiting ,
• Persistent or severe nausea and vomiting can lead to severe weight loss,
• hypokalemia and dehydration, or other electrolyte disturbances,  and metabolic alkalosis .

Nausea and Vomiting Treatment:

• Antinausea medicines should be taken by mouth, rectally, intramuscularly or intravenously.
• Fluids may be given by mouth if the patient will accept them.
• If vomiting continues, intravenous fluids and electrolytes will be required to replace those lost in the vomit.