Dizzy Fainting Spells: Causes and When to Get Help

A faint, or syncope, occurs when the brain briefly receives less blood flow. Warning symptoms may include nausea, sweating, warmth, tunnel vision, ringing in the ears, or weakness. [Dehydration](/conditions/dehydration/) and low glucose can contribute, while [Anaemia](/conditions/anaemia/) may present with dizziness and tiredness. A heart rhythm problem such as [Atrial Fibrillation](/conditions/atrial-fibrillation/) is another possibility, especially when an episode occurs without warning or during exertion. Fainting is not a diagnosis by itself.

At the first warning, lie flat and raise your legs if possible. If someone has fainted, keep them flat, check breathing, protect them from injury, and do not give food or drink until fully awake. Turn them on their side if they are vomiting. Once alert, rise slowly and drink water if safe. Do not drive, swim alone, use heights, or operate machinery until the cause has been discussed with a clinician.

Call emergency services if the person is not breathing normally, does not wake promptly, has chest pain, severe breathlessness, a seizure, a serious injury, new weakness, or confusion. Arrange urgent assessment for fainting during exercise, while lying down, with a racing heartbeat, or without warning. Even a recovered episode should be reviewed when it is a first event, repeats, or follows a new medicine.

Tell your doctor what you were doing, your position, warning symptoms, recovery, injuries, medicines, fluid intake, and family history of sudden heart problems. Ask whether you need blood pressure checks, an electrocardiogram, glucose testing, or further monitoring.