Can You Faint in a Sauna (And How to Prevent It)

Medically reviewed by Dr. Justin Ternes
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Visiting the sauna can be a relaxing experience that eases the mind and body. Generally speaking, most healthy adults can visit the sauna without health complications. However, it is possible for some individuals to faint or suffer adverse health effects.

It is possible to faint during or after using a Sauna. The heat can lower blood pressure by causing the blood vessels to dilate. Dehydration and hyperthermia are also risks. Consult your doctor beforehand, drink lots of water, and limit your sessions to 10-20 minutes if you’re worried about this.

Don’t cancel your spa trip just yet. If you aren’t taking specific medications or have certain diseases, it’s unlikely that you’ll faint from a sauna session. However, there are risks to be aware of and precautions you can take. Here’s what you need to know.

Can a Person Faint While Being In a Sauna?

Senior woman sitting in sauna

Unfortunately, it is possible to faint in a sauna or after using one. Fainting is usually the result of a temporary drop in blood pressure. The high temperatures in a sauna cause your blood vessels to dilate or open up. This allows blood through your veins easier, and the heart doesn’t have to pump as hard.

Although a reduction and blood pressure can be beneficial to some, it can be dangerous for others. Low blood pressure can cause you to feel light-headed, nauseous, experience blurred vision, and even faint. Those with blood pressure issues should avoid saunas and consult their doctor beforehand.

3 Factors That Causes a Person To Faint In a Sauna

Generally speaking, saunas are safe for most healthy adults. However, saunas can lower blood pressure and cause dehydration and hyperthermia. Let’s dive a bit deeper.

Low Blood Pressure

As mentioned earlier, low blood pressure, or hypotension, is one of the primary causes of someone fainting in a sauna. The high heat from a sauna can lower blood pressure, as they cause the blood vessels to open up.

Blood pressure varies throughout the day, so individuals without issues may still experience negative symptoms after using the sauna. Symptoms of low blood pressure can include:

  • Dizziness or lightheadedness
  • Fainting
  • Blurred or fading vision
  • Nausea
  • Fatigue
  • Lack of concentration

Adults over 65, people who take certain medications, and certain diseases can increase the risk of low blood pressure. If you suffer from low blood pressure, you should avoid using the sauna or consult your doctor beforehand.

Dehydration

A sauna session typically lasts 15-20 minutes; any longer and you can suffer from dehydration. Dehydration happens when you use or lose more fluids than you take in. Not having enough fluids can cause severe health consequences if left untreated. If you’ve been in the sauna too long, you may experience:

  • Extreme thirst
  • Less frequent urination
  • Dark-colored urine
  • Fatigue
  • Dizziness
  • Confusion

Severe dehydration can also lead to electrolyte imbalance, seizures, heart injuries, hypovolemic shock, and kidney problems.

Hyperthermia

Hyperthermia is the opposite of hypothermia, meaning your body temperature is abnormally high. Hyperthermia is not the same as having a fever. Heat fatigue, heat cramps, heat exhaustion, and heat stroke are all forms of hyperthermia.

Hyperthermia can cause low blood pressure and fainting in some cases. You may experience some of these symptoms as well:

  • Blurred vision
  • Dizziness
  • Fast breathing or heart rate
  • Fatigue
  • Headache
  • Lightheadedness or fainting
  • Low blood pressure
  • Muscle aches or cramps
  • Nausea and vomiting
  • Weakness

How to Use a Sauna Safely

Saunas have been linked to a wide variety of health benefits. Most healthy adults can use a sauna without any complications. However, improper sauna use or using a sauna with preexisting conditions can be dangerous. Here’s how to use a sauna safely.

Consult Your Doctor Beforehand

Be sure to consult your doctor before using the sauna, especially If you suffer from low blood pressure, diabetes, certain diseases, or take specific medications.

Everyone’s body is different, and you may or may not be eligible to use a sauna.

Stay Hydrated!

Hydration is one of the most important factors when using a sauna. Without enough water, you may become fatigued, dizzy, or dehydrated. Be sure to drink at least one glass of water before stepping into the sauna. After you exit, slowly drink one to four glasses to rehydrate.

Avoid Alcohol

In some cultures, It’s customary to drink alcohol before or during a sauna session. However, drinking alcohol before using a sauna can increase your chances of dehydration and discomfort. Avoid alcoholic beverages before and after using a sauna.

Cool Down Slowly

It’s tempting to jump into a cold shower or pool right after leaving the sauna. However, this can place a significant amount of stress on your body and cardiovascular system.

In some cases, cooling down too fast can cause you to faint. Be sure to cool down slowly with a glass of cold water. You can also take a cool shower that isn’t freezing cold.

Dress for the Occasion

You probably won’t see many people wearing a suit in a sauna. It’s important to pick the right attire for a sauna session. Swimsuits can be the obvious choice, but they can lock in heat and sweat.

Use loose, breathable fabrics instead. Cotton can help absorb excess heat and sweat. Be sure to avoid sweats, tight-fitting clothing, and jewelry.

How Long Should You Stay In A Sauna?

Woman in the sauna

So, how often and how long can you use a sauna without suffering negative health complications? The answer may depend on your experience level.

Beginners shouldn’t spend more than 5-10 minutes per sauna session and only visit 3-4 times a week. You should also start on lower heat settings if you’re new to saunas. It’s best to practice caution and work your way up, even if you feel fine.

Intermediate and experienced sauna goers can increase the length of their sessions by five-minute increments at a time. Be sure to avoid sitting in a sauna for more than 15-20 minutes, even if you’re a seasoned pro.

Regardless of your experience level: If you start to feel dizzy, nauseous, or fatigued, step out of the sauna immediately. Find a cool place to sit down until you feel stable. Drink plenty of water, dress properly, and consult your doctor beforehand.