FAINTING (Vasovagal Syncope)

Fainting or syncope, as it is medically known, is a medical condition characterized by a temporary loss of consciousness due to a sudden drop in heart rate and blood pressure, leading to reduced blood flow to the brain. It can also present as near-syncope, where a person feels faint but does not fully lose consciousness. 

The condition is typically triggered by a response from the autonomic nervous system known as vasovagal syncope, involving the interplay between the sympathetic and parasympathetic nervous systems. While the sympathetic nervous system is responsible for the “fight or flight” response, raising heart rate and blood pressure to help the body respond to threats and stress, the parasympathetic nervous system promotes “rest and digest” functions. It can reduce the heart rate and lower the blood pressure if the brain senses that the body has been injured. This protective mechanism keeps a person from bleeding to death in the case of bleeding due to wounds. Thus, the parasympathetic nervous system is a mechanism of the body to protect the body from death due to blood loss. The sympathetic nervous system when stimulated causes a person to run faster, hit harder and jump higher. The parasympathetic nervous system when stimulated puts a person on the ground, fainting from low blood pressure and a low heart rate in an attempt by the body to limit the loss of blood.

The Vagus nerve, a key component of the parasympathetic system, can become overly active in some people, causing vasovagal syncope, prompting a swift and excessive drop in heart rate and blood pressure, resulting in fainting even with trivial triggers such as seeing human blood. Some people have an over active parasympathetic nervous system.

Understanding the triggers of vasovagal syncope can help in managing the condition. Common triggers include prolonged standing, heat exposure, dehydration, emotional stress, pain, and seeing blood.

Treatment includes:

1. Increasing fluid intake to stay well-hydrated and adding more salt to the diet can help maintain blood volume, thereby improving circulatory stability and blood pressure.
2. Caffeine should be avoided as it may contribute to dehydration and affect cardiovascular responses.
3. If you start to feel faint, it is crucial to take immediate action to prevent potential injuries from a fall. Sit or lie down as soon as possible to help restore blood flow to the brain. Elevating your legs while lying down can also facilitate this.
4. If fainting episodes occur frequently or disrupt daily life, it is advisable to consult us in an office visit for further evaluation and management.
5. An oral medication that causes fluid retention can be prescribed.
6. A cardiologist can be consulted in refractory cases or cases which are not clear cut.