What Causes Fainting?

Q. Recently my husband had laser eye surgery and while I was with him during the procedure, I passed out. I didn't think too much of it, except for the fact that one of the assistants in the lab said that I was seizing while I was out. I have also noticed that lately I've had some twitching in my right eye and sometimes I am a little shaky. Could these two things be related? Should I be concerned?

A. Some people pass out quite easily when they see "gory" or frightening scenes, or have painful (or what they think might be painful) procedures, such as having blood drawn. To see eye surgery, or to even imagine it on your husband, may have triggered the faint that you had. At that time, your blood pressure and heart rate both become quite low. It is not unusual to see "twitching" which to an untrained eye may look like a seizure. This is unlikely to be a true seizure such as is seen in epilepsy. However, I would not give you that diagnosis until I thoroughly evaluated you, since that can impact driving or insurance issues. It is also unlikely, although not impossible, that the twitching in your eye is related to this faint, although both conditions worsen with stress, lack of sleep, etc.

The first test I would do is a tilt-table test that will see if you have the propensity to faint easily. If this is positive (if you pass out), your doctor may prescribe a low dose of a medication called a beta-blocker which will help decrease the likelihood of fainting. Other important preventive strategies include drinking LOTS of water, especially during warm weather; beginning an exercise program; avoiding caffeine; and gently increasing your salt intake.

If the tilt-table test is negative, I would then look into other causes and an electrical encephalogram (EEG). This is a brain-wave test which will detect areas in your brain prone to seizures. Neither of these tests are painful and both can quickly reassure you as to the problem. See a neurologist to arrange for both of these tests.