Low blood pressure, called hypotension, can cause frequent fainting. It occurs when the heart rate slows because of stimulation of the vagus nervea nerve that runs from the brain to several organ systems, a reaction sometimes referred to as a vasovagal response.
Hypotension can also occur as a side effect of a drug, or an underlying neurological or cardiovascular condition. Standing up too quickly, coughing or using the bathroom may trigger hypotension.
Before you faint, you might experience nausea or sweating or have trouble breathing. Sitting down and putting your head between your knees works in most cases. Another way to stop a fainting episode is through physical counterpressive maneuvers (PCMs). These exercises can be particularly useful if you feel faint when you stand up or if you feel faint and have no easy or safe place to sit or lie down. PCMs are simple movements that raise blood pressure and keep blood flowing to the brain.
Perform any or all of these movements when you start to feel faint:
- Clasp your hands, interlocking your fingers. Then pull your arms in opposite directions.
- Cross your legs at the ankles. Squeeze your thighs together and tense the abdominal muscles.
- Rhythmically squeeze a soft ball.
- Tense the muscles in your thighs and abdomen.
If you often feel faint or have experienced passing out, see your doctor. He or she may be able to treat the underlying condition and eliminate fainting episodes altogether.
Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50