A few days ago, I was dropping my daughter off for her first day of preschool. While waiting in line, I broke out into a sweat and experienced an intense feeling of nausea. I turned to the teacher, who seemed suddenly very far away, and asked, “Is it hot in here to you?” The only thing I heard before collapsing to the floor was a fuzzy, “Are you okay?”
When I woke up a few seconds later, drenched in my own sweat and somehow lying on one of the preschoolers’ nap-time cots, I realized that I’d fainted. I went to the doctor later that day to determine what may have caused the incident, and, although we didn’t find out the exact cause, my doctor and I discussed the many possibilities.
Here are some of the most common causes of vasovagal syncope– the most common type of fainting.
Anxiety
Anxiety, and many of the effects associated with it, can cause fainting. Sudden stress or emotional shock can cause a sudden rush of adrenaline and a resulting increase in blood pressure and heart rate. This can cause vasovagal syncope. Since I have an anxiety disorder, my doctor pointed out that it was one possible cause of fainting spell.
Heat Exposure
Prolonged exposure to extreme heat can cause fainting. It is, in fact, one of the warning signs of en impending heat stroke or heat exhaustion. You can prevent this problem by staying in an air-conditioned building when in extreme temperatures, and by drinking plenty of water to prevent the fainting and other unpleasant effects.
Standing for Long Periods of Time
When you stand for an extended period of time, it allows blood to pool in your legs, which lowers your blood pressure, sharply reducing bloodflow to your brain. Your body collapses, or faints, to restore bloodflow in this situation.
Low blood sugar, caused by diabetes, skipped meals, or an unhealthy diet, can occasionally cause episodes of fainting. Your health care provider may check your blood sugar or test you for diabetes if you have fainted recently.
Straining
Occasionally, straining while coughing, exercising, defecating, swallowing, or even urinating may cause an vasovagal syncope. If this happens frequently, your doctor may need to evaluate your heart health.
The Sight of Blood
The sight of blood, or the sensation of having blood drawn, can cause a psychological and physiological response that leads to fainting. This is partly caused by the drop in blood pressure from losing blood, and partly by the natural anxiety response associated with witnessing blood loss. In this case, fainting needs no treatment.
Medications
When I experienced a fainting spell, I happened to be taking several new medications at once for an infection I’d recently acquired. Because there were several medicines involved, it would be impossible to tell which, if any, of them were the cause of the problem. However, your doctor might look at your medications as a possible cause of fainting, especially if you recently started taking a new drug.
Heart Conditions
People with many types of cardiovascular conditions are more prone to fainting spells. Cardiac arrhythmia, mitral valve prolapse, high blood pressure, and low blood pressure can all make people more susceptible to fainting. Your doctor may perform tests to determine if you have any of these conditions, and to appropriately treat them if you do.
Many other, less common causes of fainting can also exist. While fainting itself is not always an emergency, it is a cause to get a prompt evaluation by an expert to determine the nature and extent of your condition and related problems. Effective evaluation and treatment by a trained professional can prevent future fainting spells. For more information, visit Mayo Clinic, which offers more information about vasovagal syncope and its causes.
