Why Do I Feel Sick After a Sauna?

Using a sauna can be an extremely relaxing and rejuvenating experience for both the mind and body. However, some people leave the sauna feeling faint, nauseous, or generally unwell. If you‘ve ever asked yourself "why do I feel sick after a sauna?" this comprehensive guide will provide detailed answers and expert advice.

As a home renovation expert who is passionate about health and wellness, I‘ve done extensive research into sauna use. In this guide, I‘ll share key insights from scientific studies, health organizations, and sauna experts to help you understand what happens in the sauna, why you may feel ill afterwards, and how to use saunas safely.

A Closer Look: How Saunas Affect the Body

To understand why you may feel sick after sauna use, let‘s first take a more in-depth look at the complex physiological changes that occur:

Increased Core Body Temperature

• The high heat and humidity in a sauna causes your core body temperature to rise rapidly, often up to 104°F or higher. This significant increase above normal levels (around 98.6°F) triggers your heart to beat faster and harder in an effort to cool you down.

Profuse Sweating

• As your body temp rises, your sweat glands kick into high gear, releasing large amounts of fluid onto the skin. This causes substantial dehydration as you lose water and essential electrolytes like sodium, potassium and magnesium.

• According to the Mayo Clinic, an average sauna session will lead to sweating out around 1 pint (16 oz) of fluid. Prolonged sweating can cause losses of over 1 quart which severely depletes the body‘s water content.

Blood Vessel Dilation

• Increased heat also triggers your blood vessels to dilate widely. This allows more blood to flow to the surface of your skin so heat can dissipate through radiation and convection.

• However, this rapid blood vessel dilation lowers your blood pressure substantially. One study showed an average systolic blood pressure drop of 30 mmHg after 15 minutes in a sauna.

While these bodily responses serve to cool you down and provide health benefits, excess fluid loss, heat stress and blood pressure drops can also make you feel quite ill if proper precautions aren‘t taken.

Key Differences Between Sauna Types

Understanding the key differences between the two main types of saunas can help you determine which option may be less likely to cause adverse effects:

Traditional Finnish Saunas

• Use dry radiant heat from hot rocks heated to extremely high temperatures – typically 700-1000°F.

• Air temperatures inside the sauna cabin range from 160-200°F.

• Steam is sometimes added by splashing water on the hot rocks which increases humidity levels.

• Less efficient sweat evaporation due to the dense, humid air. This prevents the body from cooling as effectively.

Infrared Saunas

• Use infrared lamps emitting light in the 700 to 1000 nanometer wavelength range which directly heats your body without warming the air much.

• Operate at much lower ambient temperatures – usually 100-150°F.

• Do not contain any rocks or water, so the environment stays dry.

• Sweat evaporates rapidly allowing better cooling.

• May feel more comfortable and less oppressive due to lower heat.

• One study showed core body temps rose less and heart rates increased less in infrared vs traditional saunas.

So in general, infrared saunas provide similar benefits with less fluid loss and cardiovascular stress, which can help prevent feeling sick afterwards.

Dehydration – A Common Cause of Feeling Unwell After Sauna Use

One of the most common reasons for nausea, dizziness or fainting after sauna use is dehydration. Here are some key signs your body is dangerously depleted of fluids and electrolytes:

• Intense thirst

• Infrequent urination – less than 4 times a day

• Dark yellow or amber urine color with a strong odor

• Fatigue, lethargy

• Headaches, confusion

• Dry mouth, eyes and lips

• Dizziness when standing due to low blood pressure

• Muscle cramping due to electrolyte imbalance

• Skin lacks elasticity and remains “tented” when pinched

Dehydration reduces blood volume which makes the heart work harder to pump blood through the dilated vessels. This added cardiovascular strain combined with low electrolyte levels can certainly leave you feeling ill after sauna use.

According to a meta-analysis, even mild dehydration with losses of just 1-2% of body weight can impair mood, concentration, and sports performance. More severe losses of over 3% of body weight can produce troubling symptoms.

Heat Exhaustion and Heat Stroke – Serious Risks

If dehydration goes unchecked, it can progress to dangerous heat-related illnesses like heat exhaustion and heat stroke:

Heat Exhaustion Signs

• Headache, nausea or vomiting

• Heavy sweating with moist, cool skin

• Fast breathing and heart rate

• Muscle cramps

• Weakness, fainting, agitation

• Dilated pupils

• Volume depletion

Heat Stroke Symptoms

• Body temp over 103°F

• Rapid heartbeat, low blood pressure

• Throbbing headache

• Dizziness, confusion

• Nausea, vomiting

• Hot, red, dry skin with no sweating

• Seizures or unconsciousness

If you experience ANY of these symptoms during or after sauna use, get out immediately and seek medical help. Heat stroke is a life-threatening emergency requiring rapid cooling and IV hydration. Don‘t take chances with heat-related illness.

Individuals Who Should Avoid Sauna Use

For certain groups, saunas may pose higher health risks. Use caution or avoid entirely if:

• You‘re pregnant – increased core temperature is unsafe for the fetus.

• Under age 10 – children can‘t regulate temperature as effectively.

• Over age 70 – heat regulation mechanisms decline with age.

• Have heart disease – the heat taxes the cardiovascular system.

• Have low blood pressure – heat expands vessels further lowering BP.

• Take medications like diuretics or beta blockers – can impair cooling and dehydrate.

• Have a condition affecting nerves or temperature regulation.

• Are under the influence of alcohol or recreational drugs which impair judgment.

If you have any medical concerns, talk to your doctor before using a sauna. They can help assess your individual level of risk. Those with health conditions may need to take extra precautions like limiting time and temperature or avoiding use altogether if the risks are too high.

Safe Sauna Use Tips to Prevent Illness

Here are some vital practical tips to follow so you can use your sauna safely without negative side effects:

Hydrate, Hydrate, Hydrate

Drink plenty of cool water before, during and after sauna sessions. Sports drinks containing electrolytes like Gatorade can help replenish what‘s lost through sweat. Avoid alcohol which further dehydrates you.

Start Low and Slow

Begin with shorter sauna sessions, around 5-10 minutes at first. Gradually increase time while paying close attention to how your body responds. Start at lower temperatures around 120-150°F and slowly work your way up to higher heat levels only if tolerated well.

Listen to Your Body

If at any time you start to feel sick – get out immediately. Don‘t try to “tough it out” if you notice any concerning symptoms arise. Stopping at the first sign of discomfort can prevent progression to dangerous levels of dehydration, heat exhaustion or heat stroke.

Allow Time to Cool Off

Don’t immediately jump into a cold shower after sauna use when your body is already hot and dilated. Allow at least 10-15 minutes to cool down gradually. This gives your cardiovascular system time to normalize.

Check with Your Doctor if Unsure

If you have any uncertainty about whether it’s safe for you to use a sauna, check with your physician first. They can help assess your individual health risks. Some people may need to take extra precautions or avoid saunas completely if the potential harms outweigh benefits.

Enjoy Saunas Safely and Comfortably

Used appropriately, saunas provide many evidence-based health benefits like temporary relief of pain, enhanced blood flow, relaxed muscles, mental relaxation, and improved immune function. By taking a few simple precautions, you can enjoy all the positive effects safely without ending up feeling sick, dizzy or fatigued afterwards.

Be sure to closely monitor your body’s response during and after sessions. Stop immediately at the first sign of discomfort. Stay optimally hydrated and avoid drastic spikes in temperature or humidity. Allow time to cool off gradually afterwards. If you have any medical concerns, consult your doctor before using a sauna.

With proper precautions, saunas can be an extremely therapeutic form of passive heat therapy for both mind and body. I hope this detailed guide gives you a deeper understanding of how to use them safely so you can reap all the benefits without any negative side effects. Let me know if you have any other sauna-related questions!