What should I do now?
Call 911
Call 911 for new or unexplained chest pressure that persists or returns, severe trouble breathing, collapse without normal recovery, or sudden face/arm weakness or trouble speaking. Do not drive yourself.
Contact your care team
Unexplained fainting needs assessment. Fainting during exercise, with chest symptoms, or with known heart disease can require urgent care.
Keep your care plan
Follow the safety and driving plan from your care team; record a witness account when available.
SECTION 1
What is fainting or nearly fainting?
Syncope is a brief loss of consciousness caused by a temporary drop in blood flow to the brain. Near-syncope means feeling as though you may pass out without fully losing consciousness.
You may have nausea, sweating, dimming vision, or lightheadedness beforehand. Some episodes happen with little warning.
Fainting has several possible causes. Some are relatively common reflex reactions; others involve the heart. Unexplained fainting deserves medical assessment, even when you recover quickly.
Updated October 2026. Educational information; your own care plan may differ. Medical illustrations are simplified examples for teaching.