Nausea is a common, non-specific symptom with many causes. Frequent ones include indigestion, acid reflux, gastritis, viral gastroenteritis, motion sickness, anxiety or stress, migraines, and side effects of medicines. In people who can become pregnant, early pregnancy is a very common cause of persistent nausea. Eating habits, alcohol, and dehydration can also play a role.
Most short-lived nausea settles with rest, small bland meals, sips of fluid, and avoiding strong smells. See a doctor if nausea lasts more than a few days, keeps you from eating or drinking, causes weight loss, or comes with persistent vomiting.
Seek urgent care if nausea comes with severe abdominal pain, vomiting blood or material that looks like coffee grounds, a severe headache, chest pain, signs of dehydration, confusion, or a stiff neck. A clinician or pharmacist can advise on safe relief, including in pregnancy. This is general information only.