Vasovagal Syncope
Vasovagal syncope is a condition that leads to fainting when your body overreacts to a stimulus, such as the sight of blood, excess heat, intense emotion, or more. It occurs when your blood pressure drops so low that not enough blood reaches your brain, and your heart may slow down as well.
Vasovagal syncope usually requires no treatment as long as you avoid situations that trigger it, but if the fainting occurs so often that it interferes with your quality of life your doctor may intervene. He may prescribe medications that stabilize your blood pressure or control your nervous system response. In extreme cases, he may insert a pacemaker if abnormal heart rhythms are detected.