January 01, 2019

Should I see a doctor after a fainting spell?

Q: I had a fainting spell the other day, which was new for me. I don't feel unwell, but a friend I was with at the time insists I should see my doctor. Is that necessary?

A: Yes, see your doctor.

Fainting, or passing out — a temporary loss of consciousness also known as syncope — is caused by insufficient blood flow to the brain. Some causes of syncope are fairly benign, such as from dehydration or during a frightening event such as a blood draw. But there are potentially serious and even life-threatening causes, including heart and neurological conditions, especially in adults over 60.

Your doctor will likely perform a detailed history to look for any medical, environmental or behavioral factors that may have caused you to faint. For example, missed doses of a medication, prolonged standing, or anxiety in a crowd may contribute to syncope.

A physical examination may offer important clues, as well. This includes measurement of your blood pressure and heart rate, listening to your heart, and completing a neurological exam. Syncope occurs when your blood pressure falls too low, which may occur when your heart rate is excessively fast or slow, such as with an arrhythmia. A detailed history and exam may identify the cause of syncope. Often, an electrocardiogram (ECG) or additional heart testing will also be recommended to look for any abnormal heart rhythms.

Other tests may include a complete blood count, electrolyte panel, and tests of your blood sugar and thyroid function. You may be referred for a heart ultrasound (echocardiogram), stress test or tilt table test. If you took a hard fall, imaging tests may be done to look for any fractures or other trauma.

Management of syncope depends on...