Nausea is the unpleasant sensation of feeling sick or queasy, often with the urge to vomit. It is not an illness itself but a symptom of many different conditions, ranging from mild digestive issues to more serious underlying problems. Nausea can last for a short time or persist for longer periods depending on its cause, and it may be triggered by physical, emotional, or environmental factors.

Common causes include motion sickness, infections such as gastroenteritis, food poisoning, overeating, and migraines. Nausea can also occur due to stress, anxiety, or strong smells. In some cases, it may be linked to hormonal changes such as pregnancy or menstruation. Certain medications and treatments can also irritate the stomach and lead to nausea.

When nausea occurs, the body’s digestive system slows down, and signals are sent between the stomach and the brain’s vomiting centre. This can create a feeling of unease, sweating, or dizziness. Vomiting may follow, though sometimes nausea passes without it. Persistent or severe nausea can lead to dehydration and fatigue if fluids and food are not replaced.