Vasovagal syncope (fainting)
About Vasovagal syncope (fainting)
Fainting caused by a vasovagal reaction. A vasovagal reaction is the most common cause of fainting. It is an over stimulus of the parasympathetic nervous system by such triggers as the sight of blood or extreme emotional distress. The response causes a slowing of the heart rate and a drop in the blood pressure resulting in decreased blood flow to the brain and a loss of consciousness. It is the reason people faint when they hear bad news or have their blood drawn.Symptoms
Sudden nausea, lightheadedness and fainting after seeing blood or an emotional event. Other symptoms include: sweating, vomiting.Tests & Diagnostics
A history and physical exam will be performed. Tests may be done to rule out other causes of the fainting.Common tests: Complete blood count (CBC), Comprehensive metabolic panel (CMP), CT Scan, D-Dimer, EKG, Troponin, Urinalysis (UA), X-ray.
Conventional treatment summary
The main therapy is avoidance of the trigger. Immediately sitting down or laying down at the first warning of the event may prevent the fainting.Medical specialties
Internal Medicine · Pediatrics · Family Practice
This page is educational content, not medical advice. Always consult a qualified clinician for diagnosis and treatment of Vasovagal syncope (fainting).