Fainting: Why It Happens and What to Do
Medically Reviewed by Dr. Pedro Yelamo Vera, MD
Licensed Physician No. 484814280 · Official Medical College of Bizkaia (Spain)Last reviewed: 31 October 2026
Fainting is usually harmless, but sometimes it is not. What to do if you feel faint, how to help someone who faints, and when to call 112 in Spain.
You don't have to figure this out alone
Dr. Pedro Yelamo Vera is an independent, bilingual GP licensed in Spain. Book a 15-minute video consultation in English or Spanish for €50, with a private electronic prescription issued under Spanish law when clinically appropriate.
Fainting is a short loss of consciousness. It happens when less blood reaches the brain for a moment. Most faints are harmless and you wake within a minute. If you feel faint, lie down and raise your legs. If someone faints, lay them on their back, raise their legs and check they breathe. Then find out why it happened.
- Fainting means passing out for a short time because less blood reaches the brain. Doctors call it syncope.
- Warning signs: dizziness, sweating, feeling hot or sick, and blurred or dark vision.
- Lie down with your legs up, or sit with your head between your knees. Cross your legs or clench your fists.
- Call 112 if the person does not wake within 1 minute, has chest pain or a racing heart, or fainted during exercise or lying down.
- Everyone who faints should see a doctor to find the cause. In Spain you will hear lipotimia, desmayo and síncope.
Dr. Pedro Yelamo Vera is a GP licensed in Spain (Colegiado No. 484814280).
For a medical emergency, call 112 or go to the nearest local emergency department. Do not wait for a video consultation or an online reply.
What is fainting, and what does lipotimia mean?
Fainting is a brief blackout. Blood pressure drops for a moment, so less blood reaches the brain. You lose muscle tone and fall. Then you wake up on your own, usually quickly. Doctors call a full faint syncope.
In Spain, people often say lipotimia or desmayo. Doctors use síncope when you pass out. They say presíncope when you nearly pass out but stay awake. A Spanish school health guide warns that lipotimia and mareo are vague words. So describe what happened to your doctor: did you black out, or only nearly?
Why do people faint?
The most common type is the reflex faint, also called vasovagal syncope. A trigger makes the heart slow and the blood vessels widen for a moment. The NHS and MedlinePlus list these common triggers:
- Standing up too fast, or standing still for a long time.
- Being too hot, as in a Spanish summer or a crowded place.
- Not eating or drinking enough.
- Pain, fear, shock or the sight of blood.
- Hard coughing, straining on the toilet, or passing urine at night.
- Alcohol or drugs.
Some medicines lower blood pressure and can cause faints. MedlinePlus names medicines for high blood pressure, anxiety and depression. Do not stop a medicine on your own. Ask your doctor to review it.
Less often, a faint has a serious cause. This includes heart rhythm problems, heart disease, low blood sugar, bleeding or severe dehydration.
What does it feel like just before you faint?
The NHS lists these warning signs:
- Feeling dizzy or light-headed.
- Sweating, or feeling warm or hot.
- Feeling sick.
- Changes in vision, such as blurring or a dark tunnel.
MedlinePlus adds weakness, fading sounds and a pale face. These signs give you a few seconds to act.
What should you do if you feel faint?
- Lie down and raise your legs. If you cannot, sit and lower your head between your knees.
- Tense your muscles. The NHS suggests crossing your legs while standing, rocking on your toes or clenching your fists.
- Drink some water.
- Get up slowly. Sit for a while before you stand again.
Doctors call these counter-pressure moves. The European Society of Cardiology (ESC) recommends them for younger people who get warning signs.
What should you do if someone faints?
- Stay calm. Gently shake their shoulders and ask loudly if they are OK.
- If they do not respond, shout for help. Tilt their head back and lift their chin.
- Check their breathing for at least 10 seconds.
- If they breathe normally, lay them on their back and raise their legs.
- If they are pregnant, especially after 28 weeks, lay them on their side instead.
- If they vomit, turn them on their side so they do not choke.
- Loosen tight clothes at the neck. Keep them lying down for 10 to 15 minutes in a cool place.
The NHS says most people wake within 30 seconds. If they are not breathing, call 112 and start CPR.
Fainted in the heat, or keep feeling light-headed?
You can book a video visit with a GP licensed in Spain, in English or Spanish. He goes through what happened, checks for heat illness and warning signs, and helps you plan the next steps.
When is fainting an emergency?
Call 112 if the person:
- Is not breathing, or cannot be woken within 1 minute.
- Does not fully recover, or has trouble speaking, seeing or moving.
- Has chest pain, or a pounding, fluttering or irregular heartbeat.
- Fainted during exercise, or while lying down.
- Is shaking or jerking (a seizure), or was badly hurt in the fall.
Do not drive yourself to urgencias (A&E). The 112 call handler will tell you what to do.
US and UK advice differ a little. The NHS list is the one above. MedlinePlus, from the US, also advises an emergency call if the person is pregnant, over 50 or has diabetes. In those cases, get them checked at urgencias. Call 112 if they do not fully recover. If in doubt, call.
Do you need to see a doctor after fainting?
Yes, even if you feel fine. The NHS advises a GP visit after any faint to find the cause. See a doctor today, without waiting, if this is your first faint, if faints keep happening, or if you notice new symptoms.
The ESC guideline says every person who faints needs three things:
- A careful history. What were you doing? What did a witness see?
- An exam with blood pressure lying down and standing.
- An ECG, a quick heart tracing.
Blood tests may look for anaemia or low blood sugar. If a heart rhythm problem is possible, you may need a heart monitor or an echocardiogram.
Is fainting in children and teenagers different?
Faints are common in teenagers and are usually harmless, says the Spanish Paediatrics Association (AEP). Heat, tiredness, crowds and the sight of blood are typical triggers. In children under 4, breath-holding spells after crying are the usual cause.
Call 112 if the child does not wake within 1 to 2 minutes, or has chest pain or a racing, irregular heartbeat. Go to urgencias if the faint happened during exercise or effort, or while sitting. Go too if the child is under 6, has a known heart condition, or has a family history of sudden death. A Spanish school guide by primary care paediatricians (AEPap) gives these urgencias rules.
How can you stop fainting again?
- Avoid your known triggers where you can.
- Drink enough water, especially in hot weather or with exercise.
- Get up slowly from lying or sitting.
- Use counter-pressure moves at the first warning sign.
- If blood tests make you faint, tell the nurse and lie down for them.
Can you drive after fainting in Spain, the UK or the US?
Ask your doctor before you drive again. In the UK, GOV.UK says car drivers must tell the DVLA if fainting affects their driving. Bus and lorry drivers must report any faint. The NHS adds that you must not drive while waiting for a specialist after a referral. Spain and US states have their own medical rules for licences. Your doctor can tell you which apply to you.
Talking it through with a doctor by video
Dr. Yelamo is a GP licensed in Spain. He sees adults, children and pregnant patients by video, every day from 07:30 to 20:30 (Spain time). In the visit he will:
- Go through what happened before, during and after the faint.
- Check your medicines, your fluids and any heat exposure.
- Tell you if you need an ECG, blood tests or an in-person exam, and when not to wait.
He does not promise any test or prescription before the visit. Where clinically appropriate, following a genuine evaluation. Treatment and prescriptions are issued solely at the doctor's discretion based on evidence-based clinical guidelines.
A prescription is never guaranteed: it is issued only where clinically appropriate after a genuine evaluation, as a private electronic prescription under Spanish law. This service is for urgent, non-emergency care. In an emergency, call 112.
See how the Urgent Care video visit works. It lasts 15 minutes and costs €50.
This guide is general information. It does not replace a consultation with your doctor.
Frequently asked questions
What should I do if I feel faint?
Lie down and raise your legs, or sit with your head between your knees. Drink some water. Crossing your legs, tensing them or clenching your fists can help stop the faint.
How long does a faint last?
Usually less than a minute or two. The NHS says most people wake within 30 seconds. If someone cannot be woken within 1 minute, call 112.
Is fainting dangerous?
Most faints are harmless reflex faints. A faint is more worrying if it happens during exercise or while lying down, or comes with chest pain or a racing, irregular heartbeat. Those need urgent care.
Should I see a doctor after fainting once?
Yes. The NHS advises seeing a GP after a faint to find the cause. The check is usually simple: questions, blood pressure lying and standing, and an ECG.
What is lipotimia?
It is the everyday Spanish word for a faint or near-faint. Spanish doctors say síncope for a full faint and presíncope when you nearly pass out.
Can I drive after fainting?
Ask your doctor first. In the UK you must tell the DVLA if fainting affects your driving, and bus or lorry drivers must report any faint. Spain applies its own medical rules for licences.
Sources
- NHS: Fainting
- MedlinePlus: Fainting
- ACC: Ten points from the ESC syncope guidelines
- En Familia (AEP): Desmayos (síncopes), in Spanish
- GOV.UK: Blackouts, fainting and driving
Related guides
Medical Citations & Sources
This content is written and reviewed by a licensed physician with reference to the following official health authorities.
