nausea

Nausea is a subjective sensation of the urge to vomit, often accompanied by queasiness, pallor, sweating, or dizziness. It can occur with or without vomiting and has a wide range of causes, from self-limited illnesses to more serious medical conditions.

Common causes include gastroenteritis, food poisoning, motion sickness, pregnancy, migraines, and medication effects (for example chemotherapy, certain antibiotics, opioids). Less common causes include metabolic disorders (diabetes, kidney or liver disease), infections of the ear or brain, and psychological factors such as anxiety.

In pregnancy, nausea is common in the first trimester and may contribute to hyperemesis gravidarum in rare cases.

Nausea results from a multifactorial network involving the stomach, vestibular system, and brain, with neurotransmitters such as serotonin, dopamine, and substance P playing roles.

Evaluation is clinical. Red flags requiring urgent care include persistent vomiting with dehydration, vomiting blood, severe abdominal pain, high fever, confusion, or signs of head injury. Basic tests may include pregnancy testing and metabolic panels to guide management.

Management emphasizes treating the cause and relieving symptoms. Measures include rest, oral hydration in small amounts, and bland meals. Anti-emetics such as ondansetron, metoclopramide, or prochlorperazine are commonly used, chosen based on the cause and patient factors. In pregnancy, safe options should be considered and discussed with a clinician.

Most episodes resolve with time or removal of triggers. Chronic or recurrent nausea warrants medical assessment to identify underlying disease or therapy-related factors.