What Causes Nausea: Main Causes of Nausea

Nausea is a distressing sensation in the epigastric region, chest, oral cavity, and pharynx that often precedes vomiting. It is a common symptom and usually resolves on its own, but it may be caused by conditions that require evaluation. Below are the causes of nausea and the situations when a doctor is needed.

Nausea: what it is and how it occurs

Nausea is not a disease but a symptom. The mechanism is described as follows: gastric tone is reduced, peristalsis (wave-like contractions of the wall) is absent or slowed, while the tone of the duodenum and proximal jejunum is increased, and duodenogastric reflux occurs — the backflow of intestinal contents into the stomach. During retching, the tone of the antral part of the stomach increases, while that of the body and cardia decreases. The branch of medicine that studies nausea and vomiting is called emetology.

What causes nausea: common digestive causes

The most common causes are gastrointestinal diseases, dietary indiscretions, poisonings, and infections. The list of causes of nausea and vomiting includes gastroenteritis (intestinal infection) and other infections, food poisoning, GERD (gastroesophageal reflux, backflow of stomach contents into the esophagus) and ulcers, and intestinal obstruction. Associated symptoms help orient, but do not replace evaluation.

• diarrhea or vomiting — norovirus or food poisoning;
• heartburn or bloating after eating — acid reflux;
• headache and high fever — infection, such as influenza;
• headache and sensitivity to light or sound — migraine;
• dizziness — labyrinthitis or vertigo.

Nausea also occurs outside of digestive causes: pregnancy (morning sickness), motion sickness, anxiety, alcohol, medications, including those used in chemotherapy, recent surgery, migraine, infection with high fever, dizziness.

Why nausea occurs in the morning

Morning nausea is one of the first signs of pregnancy; nausea during pregnancy belongs to the symptoms of early gestosis (morning sickness of pregnancy) and usually resolves by the end of the first trimester. A pregnancy test is possible in women; the cause is determined by a doctor based on history, symptoms, and examination.

What can cause nausea every day

Nausea that frequently returns is a reason to see a doctor; possible causes include GERD, ulcers, medications, and pregnancy. The doctor looks for the cause and, if necessary, offers treatment. In diseases accompanied by weight loss (cancer, AIDS), nausea may be constant and thus life-threatening. Persistent nausea without a clear explanation requires evaluation.

When nausea requires seeing a doctor

See a doctor if nausea does not resolve within several days or frequently returns. Immediate contact with a doctor is required for: suspected poisoning, vomiting lasting longer than 24 hours, blood in vomit, severe abdominal pain, severe headache with neck muscle stiffness, signs of dehydration (dry mouth, infrequent urination, dark urine). Diagnosis includes history-taking and examination with assessment of dehydration signs, blood and urine tests, and in women a pregnancy test; if necessary, upper gastrointestinal endoscopy is performed.

Nausea alone is not a reason to call an ambulance; 103/112 — if sudden nausea is accompanied by squeezing or severe chest pain, pain radiating to the arms, back, neck, or jaw, or shortness of breath (myocardial infarction is possible).

This material is for reference: it describes causes and signs but does not replace consultation with a doctor, who assesses the specific situation and determines the scope of evaluation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer