Fainting First Aid: What to Do When Someone Passes Out and When It Is an Emergency

Quick answer: if someone faints, lay them on their back, check that they are breathing, and if there is no sign of injury raise their legs about 12 inches to help blood return to the brain. Loosen tight clothing and keep them lying down until they feel better, then let them sit up slowly. Call 911 if they do not wake up within about a minute, are not breathing normally, are injured from the fall, have chest pain, a racing or irregular heartbeat, trouble breathing, confusion, or fainted during exercise or with no warning. If they are not breathing normally, start CPR.

Fainting is surprisingly common. A person standing in a hot subway car, a teenager getting a blood test, or a guest who skipped lunch and stood up too fast at a party can all suddenly slump to the floor. In most cases they come around within seconds and recover fully. A smaller number of fainting spells are a warning of a heart rhythm problem or another serious condition.

This guide explains what fainting is, how to help someone who passes out and how to tell a simple faint from an emergency. It is one of the first aid skills in our apartment emergency preparedness guide.

Sources: American Red Cross, first aid guidance on fainting and sudden illness; American Heart Association, “Syncope (Fainting)”; National Heart, Lung, and Blood Institute (NIH), information on fainting and low blood pressure; MedlinePlus (U.S. National Library of Medicine), “Fainting”; Cleveland Clinic patient information on vasovagal syncope. Checked November 2026. This article is general safety information, not medical advice. Call 911 in an emergency.

What Fainting Is

Fainting, called syncope by doctors, is a short loss of consciousness caused by a temporary drop in blood flow to the brain. The American Heart Association describes it as a sudden, brief loss of consciousness and posture, followed by spontaneous recovery.

When a person faints and falls or lies flat, gravity helps blood return to the head. That is why most people wake up within seconds to a minute. Recovery is usually complete, though they may feel tired, washed out or a little nauseated for a while.

Common types

• Vasovagal (reflex) fainting is the most common type, according to MedlinePlus and the Cleveland Clinic. A trigger causes the heart rate and blood pressure to drop suddenly. Typical triggers include the sight of blood or a needle, strong emotion, pain, standing for a long time, heat and straining.
• Orthostatic fainting happens when blood pressure drops on standing up. Dehydration, some medicines, blood loss and long bed rest can cause it.
• Cardiac fainting is caused by a heart rhythm problem or structural heart disease. This type is less common but more dangerous, and it is one reason fainting should not be brushed off without thought.

Warning Signs Before a Faint

Many people get a few seconds of warning before they pass out. MedlinePlus lists these common signs:

• Feeling lightheaded, dizzy or woozy
• Nausea or a queasy stomach
• Sweating, or skin that feels cold and clammy
• Turning pale
• Blurred or tunnel vision, or the vision “graying out”
• Ringing in the ears or muffled hearing
• Yawning or a sudden sense of weakness

If you feel faint yourself

Lie down right away, wherever you are, and raise your legs if you can. If lying down is not possible, sit and put your head between your knees. Do not try to walk it off or rush to a bathroom, since falling from standing is how most fainting injuries happen. Stay down until the feeling passes completely, then get up slowly.

If someone near you looks faint

Help them sit or lie down before they fall. Guide them to the floor rather than trying to hold them upright. Clear the area of anything they could hit.

First Aid When Someone Faints

American Red Cross first aid guidance for someone who has fainted follows these steps:

1. Check the scene and the person. Make sure the area is safe, then tap the person and shout to see if they respond.
2. Check breathing. Look for normal breathing for no more than 10 seconds. Occasional gasps are not normal breathing.
3. If they are not breathing normally, call 911 and start CPR. Use an AED if one is nearby. Our hands-only CPR and AED guide explains how.
4. If they are breathing, lay them on their back. Raise their legs about 12 inches, unless you suspect a head, neck, back or leg injury, or raising the legs causes pain.
5. Loosen tight clothing around the neck and waist.
6. Watch for recovery. Most people come to within a minute. If they do not, call 911.
7. If they vomit, roll them onto their side so the airway stays clear.
8. Keep them lying down for several minutes after they wake up, and let them sit up slowly before standing.

What not to do

• Do not slap the person or throw water on their face
• Do not give anything to eat or drink until they are fully alert and able to swallow
• Do not prop them upright in a chair while they are unconscious
• Do not let them stand up quickly or walk away alone right after waking
• Do not use smelling salts or similar products

When Fainting Is an Emergency

Most single faints in otherwise healthy people are not dangerous. Still, the American Heart Association and MedlinePlus list situations that call for emergency care. Call 911 if the person:

• Does not regain consciousness within about a minute
• Is not breathing normally
• Has chest pain, pressure or discomfort
• Has a fast, pounding, skipping or irregular heartbeat
• Is short of breath
• Fainted during physical activity or exercise
• Fainted with no warning signs at all, or while lying down
• Is confused, has trouble speaking or moving one side of the body, or has a drooping face
• Hit their head or was injured in the fall
• Had a seizure, or lost bladder or bowel control
• Is pregnant
• Has diabetes, especially if they may have low blood sugar
• Is older, or has a known heart condition

Some of these overlap with other emergencies. Sudden face drooping or arm weakness points to a stroke. Shaking and jerking may be a seizure. Our guides to low blood sugar emergencies and head injury and concussion warning signs cover two of the most common related problems.

Even when a faint seems simple, a person who faints for the first time, faints repeatedly, or has a family history of sudden unexplained death should see a doctor soon afterward.

Fainting, Seizure or Low Blood Sugar?

Bystanders often cannot tell what caused a collapse. A few clues help, though none replaces a medical evaluation.

Feature	Simple faint	Seizure	Low blood sugar
Warning signs	Lightheaded, pale, sweaty, vision graying	Sometimes an aura, often none	Shaky, sweaty, hungry, irritable, confused
Length of unconsciousness	Usually seconds to a minute	Often longer, with stiffening and jerking	May be gradual, with confusion before collapse
Movement	A few brief twitches can happen	Rhythmic jerking of arms and legs	Usually limp, may be confused or combative
Recovery	Alert quickly, though tired	Confused or sleepy for some time afterward	Does not improve until sugar is raised
First step	Lay flat, raise legs if no injury	Protect the head, time it, turn on side after	Give fast sugar if awake and able to swallow

A few jerks during a faint are common and do not by themselves mean a seizure. If you are unsure, treat the person as if it is the more serious condition and call 911. Our seizure first aid guide covers timing and positioning.

Fainting in Public Places and on Transit

In a crowded train, bus or elevator, the first job is giving the person space. Ask others to step back, and if you can, help the person sit or lie on the floor rather than leaving them propped against a pole. On a train, tell the operator or use the emergency intercom so staff can call for help at the next station. In an office or store, ask someone to find the building’s AED and first aid kit while you check breathing.

Staff at transit stations and large buildings often have first aid training and direct lines to emergency services. Use them, but do not wait for them before calling 911 if any red flag is present.

After Someone Comes Around

The first few minutes after waking are when a second faint is most likely. Keep the person lying down or sitting with support. Ask simple questions about what they remember and how they feel. Check for injuries from the fall, especially to the head, face and wrists.

Once they feel steady and fully alert, a drink of water or a small snack can help if they have not eaten in a while or are overheated. Help them stand slowly in stages: lying, then sitting, then standing with support.

Information to pass on to a doctor or paramedics

• What the person was doing just before fainting
• Any warning signs they described
• How long they were unconscious
• Whether there was jerking, color change or confusion afterward
• Any medicines they take and any known health conditions

Writing these notes on your phone while waiting for help saves time later.

Common Triggers and How to Prevent a Faint

People who know they are prone to vasovagal fainting can often prevent a spell. Cleveland Clinic and NHLBI information suggests:

• Drinking enough fluids, especially in hot weather
• Avoiding standing still for long periods, or shifting weight and flexing leg muscles when you must stand
• Getting up slowly from lying or sitting
• Sitting or lying down for blood draws and shots, and telling staff you tend to faint
• Lying down at the first warning sign rather than trying to push through
• Talking to a doctor about medicines that may lower blood pressure

Heat is a big trigger in cities, from crowded subway platforms to apartments without air conditioning. Our guide to heat exhaustion versus heat stroke explains when overheating has crossed into a medical emergency.

Fainting in Children and Teens

Fainting is common in teenagers, and vasovagal syncope is the most frequent cause. Triggers include standing in hot classrooms or churches, getting shots, sudden fright and skipped meals. First aid is the same as for adults.

Children who faint during exercise, while swimming, from a loud noise or startle, or who have a family history of heart rhythm problems or sudden death at a young age need prompt medical evaluation. The American Heart Association highlights exercise-related fainting as a warning sign of possible heart problems in young people.

Frequently Asked Questions

Should you raise someone's legs after they faint?

Yes, if there is no sign of injury. The American Red Cross advises raising the legs about 12 inches to help blood return to the heart and brain.

How long does fainting usually last?

Most people wake up within seconds to about a minute. If they stay unconscious longer, call 911.

Is it safe to let someone drive after fainting?

Not right away. They should not drive until a doctor has evaluated the cause, especially after a first faint or one with no warning.

Can dehydration cause fainting?

Yes. Dehydration lowers blood volume and can cause blood pressure to drop when standing, which is a common cause of orthostatic fainting.

Should I go to the hospital after fainting once?

Seek emergency care if any of the red flags above apply. Otherwise, contact a doctor to talk about the cause, especially for a first faint, repeated faints or fainting during exercise.

The Bottom Line

Fainting is a brief loss of consciousness from reduced blood flow to the brain, and most episodes are harmless. Help the person lie flat, check breathing, raise their legs if they are not injured, and keep them lying down until they recover. Start CPR if they are not breathing normally. Call 911 if they do not wake within about a minute, are hurt, or have chest pain, a racing heart, breathing trouble, confusion or fainted during exercise or with no warning.