Runners, in particular women who run in Florida's summer heat, can probably relate to what happened to French President Nicolas Sarkozy on Sunday. Simply put, he fainted, most likely from being hot and dehydrated while jogging in the French countryside.
Doctors call it vasovagal syncope, a sudden drop in blood pressure that occurs shortly after stopping overexertion.
"We see it in athletes all the time, particularly in women runners with naturally low blood pressure," says Dr. Eric Coris, director of primary care sports medicine at USF Health. "In some long, very competitive events in the heat, as many as a third of female runners will pass out or become light-headed shortly after crossing the finish line."
Most adult Americans would welcome low blood pressure, but in some people it can cause vasovagal episodes throughout life, which are essentially a response to an imbalance in the body's autonomic nervous system. That's what controls our involuntary responses such as heart rate, salivation and perspiration.
The imbalance can be triggered by a number of things, including stress, anger or extreme emotions, witnessing pain, seeing blood or needles, standing for long periods of time or quickly changing position from sitting or lying down to standing up. The result is light-headedness and a brief loss of consciousness or fainting.
Being dehydrated also can trigger a vasovagal episode. So, if a runner who already has low blood pressure becomes dehydrated while jogging or competing, blood pressure can drop even lower. The simple act of stopping a long-distance run can trigger a sudden drop in blood pressure, reduced blood flow to the brain and fainting.
The good news: "It's totally benign and recovery is usually quick," Coris said. Treatment is simple: Lie down in a cool area out of the sun, and put your feet up.
Vasovagal syncope doesn't just happen to dehydrated athletes. It can happen to anyone, but typically first occurs in the teen years. It's not an uncommon reaction to having blood drawn. People with diabetes and Parkinson's disease are at higher risk for fainting; so are migraine headache sufferers. Less often, fainting may also be a symptom of certain heart abnormalities or high blood pressure.
Frequent fainting should be evaluated by a physician. Just ask Sarkozy, who underwent a battery of tests to rule out something more serious.