Fainting

What is it?

Syncope (fainting) results from a transient drop in cerebral perfusion, causing temporary loss of consciousness and postural tone. The most common type — vasovagal syncope — is triggered by standing too long, heat, pain, or emotional stress and is generally benign. Orthostatic hypotension (blood pressure drop on standing) is another frequent cause, especially in older adults. Cardiac syncope — caused by arrhythmias or structural heart disease — carries serious risk and requires urgent evaluation. Any syncope with chest pain, exertion, or without prodrome warrants cardiac workup.

Common causes

When to see a doctor

• 1Syncope during exercise or exertion — potentially cardiac and must be evaluated urgently
• 2Syncope with chest pain, shortness of breath, or palpitations before or after
• 3Multiple episodes of syncope or presyncope in a short period
• 4Syncope in someone with known heart disease or family history of sudden cardiac death
• 5Injury from a fall during syncopal episode
• 6No clear identifiable trigger (no warning, no emotional/positional cause)

What you can do

• ✓Stay well hydrated — dehydration is a leading trigger
• ✓Increase salt intake (if medically appropriate) to expand blood volume
• ✓Rise slowly from lying or sitting positions — pause at the edge of the bed
• ✓Avoid prolonged standing in hot environments
• ✓Cross your legs or tense leg muscles if you feel lightheaded — raises blood pressure
• ✓Wear compression stockings if orthostatic hypotension is a recurring problem

Conditions that cause this symptom

Medications that may help

Treatment depends on the underlying cause. Always consult your provider before starting any medication.

Frequently asked questions