Why do I get a headache after the sauna?
By the Find My Sauna team·
Updated ·
6 min read
You come out of the sauna feeling loose and calm, and an hour later your head is pounding. It's a common complaint, and usually an easy one to fix. Most sauna headaches come down to fluid, heat or blood pressure, and a few simple habits prevent them.
The short answer
The most common reason for a headache after the sauna is dehydration: you can sweat half a litre or more in a session. Other causes are staying in too long and overheating, a drop in blood pressure, skipping food or your usual coffee, alcohol, and migraine triggers like heat and strong scents. Drink water before and after, keep rounds to 10–15 minutes, cool down slowly and eat something. See a doctor if headaches keep happening, and get help at once for a sudden, severe headache.
Dehydration
This is the usual culprit. In a 1976 study of 60 adults sitting in an 80–90 °C sauna for 20 minutes, the average sweat loss was about 450 g, nearly half a litre, and some people lost far more. Do two or three rounds and you can be well over a litre down.
The NHS lists headache alongside thirst, a dry mouth, tiredness and dark yellow pee as signs of dehydration. Often the headache doesn't arrive until after you've left. Our guide to staying hydrated in the sauna explains how much to drink.
Overheating
In that same study, after 20 minutes the average body temperature had risen to 38.6 °C, and more than one person in five went over 39 °C. Headache is one of the signs of heat exhaustion, along with dizziness, feeling sick and heavy sweating with clammy skin.
The fix is shorter rounds with proper breaks. Most people do 10–15 minutes at a time. For more on timing, read how long to stay in a sauna. The top bench is a lot hotter than the bottom one, so moving down helps too.
Low blood pressure
Heat widens the blood vessels in your skin, and your blood pressure drops. For most people that's mild and passes once they cool down. But if you leap up from the top bench and walk straight out, you can feel light-headed or even faint. In the 1976 study, three of the 60 people fainted.
Sit up for a minute before you stand. If you take blood pressure medicine, the drop can be bigger, so be extra careful and ask your doctor.
Coffee, food and alcohol
- Missing your coffee. If you usually drink coffee and skip it on a spa day, caffeine withdrawal can give you a headache. A Johns Hopkins review found symptoms usually start 12–24 hours after your last dose, and can happen even if you normally have only about one cup a day.
- Skipping meals. The NHS lists skipping meals as a common cause of headaches. A long sauna session on an empty stomach makes it more likely.
- Alcohol. It dehydrates you on top of the sweating and lowers your blood pressure further. Read sauna and alcohol before you combine them.
Migraine triggers
If you get migraines, the sauna can bring several possible triggers together: heat, dehydration and sometimes strong scents. Many people with migraine say hot weather sets theirs off, though research on weather and migraine has had mixed results.
Essential oils poured on the stones, and the scented towel-waving sessions called Aufguss, can be a problem if smells set you off. Choose a plain sauna or sit near the door. Some people with migraine find the sauna fine, others never do. Keeping a diary of when headaches happen is a good way to find out which you are.
Wood-fired saunas and fumes
A wood-burning stove is a fire in a small room. If it's badly installed, the chimney is blocked or the room is poorly ventilated, carbon monoxide can build up. You can't see or smell it. A headache with dizziness, feeling sick or confusion that starts in a wood-fired sauna and eases when you go outside is a warning sign. Get out, get fresh air and get medical advice, and don't use that sauna again until it has been checked.
What to do when it starts
- Get out of the heat and sit or lie somewhere cool.
- Drink water slowly. After a long, sweaty session, a sports drink or something salty helps replace the salt you've lost.
- Eat something if you haven't for a while.
- Rest for half an hour. Paracetamol or ibuprofen can help if it doesn't settle.
How to prevent it
- Drink a glass of water before you go in, between rounds and afterwards.
- Keep rounds to 10–15 minutes and take a proper break between them.
- Use a lower bench, or wear a felt sauna hat to keep the hottest air off your head.
- Cool down gradually and stand up slowly.
- Have your usual coffee and a light meal beforehand.
- Skip the sauna if you've been drinking or are already dehydrated.
Our sauna safety rules cover the rest.
When to see a doctor
See a GP if you keep getting headaches after the sauna even when you drink plenty, or if painkillers aren't helping. Call an ambulance or go to A&E for a headache that comes on suddenly and is extremely painful, or that comes with confusion, a stiff neck, weakness or numbness, trouble speaking or seeing, or a seizure. Treat confusion or hot, dry skin after the sauna as possible heatstroke. Ask your doctor before using a sauna if you have a heart condition or high or low blood pressure.
This guide is general information, not medical advice.
Saunas with somewhere to cool off
A sauna with cold water and a place to rest makes it much easier to take the breaks that prevent headaches. A few to try:
Contrast Club
Nashville · Sauna and cold plunge
Sauna Culture
Charlotte · Private sauna sessions
R3 Contrast
Birmingham · Finnish sauna
Frequently asked questions
Why do I get a headache after the sauna?
Usually because you have lost fluid through sweat. Overheating, a drop in blood pressure, skipping food or coffee, and alcohol are other common causes.
Is it normal to feel dizzy after a sauna?
Mild light-headedness when you stand up is common, because heat lowers your blood pressure. Sit up for a minute first. If you feel faint or unwell, get out, cool down and drink water.
Can a sauna trigger a migraine?
It can for some people. Heat, dehydration and strong scents are all reported migraine triggers. Others find the sauna does not bother them at all.
How much water should I drink after a sauna?
Roughly replace what you sweated. You can lose half a litre or more per session, so a large glass or two afterwards is a good start, plus more if you did several rounds.
Should I use the sauna when I already have a headache?
Better not. If the headache comes from dehydration, heat or a migraine, the sauna is likely to make it worse. Wait until it has gone and you have had plenty to drink.
