MSU Extension Food & Health

Sweating is an important function when it comes to your health. Sweating cools down your body through heat vaporization, the process of sweat drying off your skin. It’s a highly effective way to cool down. But sweating causes you to lose water. Your body is made mostly of water, so we need to replace it after periods of heavy sweating.

What to Know About Sweating

Everybody sweats — some a little, some a lot. You probably already know that your body sweats as a way to cool down when you’re hot or exerting yourself. But do you know what’s in sweat? And can you really sweat out toxins? Here’s everything you need to know about sweat and sweating.

What Causes Sweating?

Your body’s ideal temperature is around 98.6 degrees Fahrenheit. This number can vary a bit from person to person, but this is the average core temperature. If your body gets too hot, your brain sends a message that the body needs to cool down. This message comes from the hypothalamus, the part of the brain that controls your body’s temperature. To cool down, your body begins to release sweat.

Sweat comes from glands in your skin that can be found all over your body. You have higher numbers of sweat glands on your forehead, armpits, the palms of your hands, and the soles of your feet. These glands release sweat so that, as it evaporates, your body temperature falls.

Some normal sweating causes include:

• Exerting yourself while exercising
• Heat, like hot temperatures in the summer
• Eating spicy foods
• Stress, anxiety, or nervousness
• When you’re sick and have a fever

Overheating is dangerous, so if we didn’t sweat, we’d die.

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Sweating when you’re stressed or anxious is thought to be an ancestral trait in early humans that was needed for hunting animals or fighting off attackers. When you’re nervous, your palms and feet sweat more, which can help to improve your grip. This is because the sweat that’s released when you’re nervous helps to control humidity and friction on your skin. This could have helped early humans when it came to using tools or weapons.

What Is in Sweat?

Sweat is made up of mostly water. A small portion of your sweat contains other things, including:

• Electrolytes like sodium, potassium, calcium, and magnesium. Electrolytes help to trigger different necessary responses in your body, so it’s important to replace them after periods of heavy sweating.
• Small amounts of pheromones, which are chemicals that act like hormones outside of your body
• Bacteria that grow in the sweat that you release; this bacteria can cause body odor.
• Tiny amounts of toxins

Is Sweating Good for You?

Sweating is an important function when it comes to your health. Sweating cools down your body through heat vaporization, the process of sweat drying off your skin. It’s a highly effective way to cool down. But sweating causes you to lose water. Your body is made mostly of water, so we need to replace it after periods of heavy sweating.

Dehydration can happen after intense exercise or from being out in hot, sunny weather. This kind of dehydration can happen to both children and adults who don’t drink enough water to replace the liquid that they are sweating out.

Sweating dehydration can be tricky because you might not feel thirsty until you’re already too low on fluids. When you’re exercising or out in hot weather, it’s important to keep drinking water, even if you don’t feel especially thirsty, to avoid dehydration.

Not drinking enough water after sweating a lot can also lead to heat injury. This type of injury can range from mild cramps to heatstroke, which can be deadly.

Can I Sweat Out Toxins That Are in My Body?

In a word, no. You may have heard that sitting in a sauna or going to a hot yoga class will help your body sweat out dangerous toxins. But your sweat is 99% water. Trace amounts of metals and other chemicals can be present in your sweat, but your kidneys and liver do most of the work when it comes to getting rid of toxins in the body.

What you eat has a bigger impact when it comes to getting rid of toxins in the body. Good nutrition helps your organs to function well. Organs and systems like the urinary, fecal, and respiratory routes do most of the heavy lifting when it comes to detoxification, so these systems need proper fuel to get the job done.

You might notice that your sweat has a strange smell after you eat certain foods. Some sulfuric vegetables, like cauliflower, cabbage, and garlic, can change the smell of your sweat.

Show Sources

Better Health Channel: “Sweat.”

Houston Methodist: “How Sweat Works: Why We Sweat When We’re Hot, as Well as When We’re Not.”

International Hyperhidrosis Society: “Physiology of Normal Sweating.”

Mayo Clinic: “Dehydration.”

Michigan State University: “Is sweating good for you?”

Nemours KidsHealth: “What’s Sweat?”

Ochsner Health: “Can You Sweat Out Toxins?”

Is sweating good for you?

Learn about the relationship between sweating, hydration and health.

It is important to stay hydrated and avoid excessive heat during the hot summer months because we lose a lot of body fluid through sweat. But does this mean you should avoid sweating at all costs? Not at all.

People sweat for many reasons such as hot weather, nervousness, a fever, exercise, and being in a sauna. Sweating can dehydrate us, stress us out, or remind us our body is fighting an illness. In contrast, it may invigorate us on a hike or when working out in a gym. Besides, isn’t sweating what you are supposed to do in a sauna anyhow?

Why do we sweat?

Perspiration (or sweating) is the major way our body regulates its temperature. Water is released through glands in the skin, evaporates off the skin and the body is cooled. During exercise, muscles heat up more, so more sweat is needed. Cooling is the major function of sweating. Without it, our body could not release excess heat and we would die. This is true regardless of whether we are sick in bed or relaxing in a sauna.

What is in sweat?

• Mostly water
• Small amounts of sodium, potassium, calcium and magnesium – electrolytes that help trigger various electrical responses in the body (e.g., flexing muscles). This is the reason why drinking electrolytes during and after high impact or long periods of exercise is beneficial.

• Small amounts of pheromones, which have little significance in humans compared to other animals, but have shown interesting function in limited research studies.

• Bacteria, which grow in the released sweat and make it stink. Antiperspirants, certain shirt fabrics, and frequent bathing can remedy this.

• Small amounts of released toxins. The belief that sweat removes significant levels of toxins from the body is often exaggerated because most of sweat is made up of water. There is minor removal of heavy metals and BPA plastics but the liver and kidneys do most of the body’s detoxification. In fact, a person’s overall nutrition likely has a greater impact on body detoxification than sweating because good nutrition supports healthy organ function.

Is sweat a good thing?

From a physiological perspective, sweating is absolutely a good thing. Our body would overheat if we did not sweat. But some of the activities that cause sweating (excessive time in the heat, being nervous or sick) is associated with other problems, such as heat exhaustion, anxiety and illness. In contrast, activities such as exercise and controlled time in a sauna are healthy. This would suggest that it is not the sweating itself, but the activity behind it, which defines whether sweating is healthy or not.

Sweating during exercise usually means you are reaching a level of exercise that promotes cardiovascular health. Some evidence suggests sweatier people are getting a more intense workout, and more fit individuals sweat sooner and more profusely, but tremendous variation in the timing and amount of sweat across individuals makes those claims unreliable. Instead, focus on reaching a level of exercise (or sauna time) in which sweat actually shows up, rather than measuring the timing or amount. Just because it is summer and hot outside, do not assume it means you should not work out. On those days, exercise in air-conditioned environments, choose the cooler times of the day, and keep hydrated. Stop exercising if you experience unusual symptoms, such as dizziness and nausea.

As for saunas, research is confirming some of the long-standing beliefs of Finnish people that sweating in saunas is beneficial to health. Heat-induced stress relief and possible positive effects on heart health may be the actual benefits. Similar to exercise, the activity behind the sweating (not the sweating itself) is what is actually making us healthy.

How to counteract fluid loss when sweating:

1. Drink water throughout the day – not just when you think you need it.
2. Avoid caffeinated and alcoholic drinks, which can amplify the effects of dehydration.
3. Choose water over sugary drinks, and be careful not to drink too much fruit juice. Instead, add flavor to water with flowers and fruit infusions that use less sugar.
4. During intense exercise and heavy sweating, replace lost electrolytes with drinks or foods that contain them. For example chicken, fish, milk, yogurt, greens, sweet potatoes, avocados, mangoes, pomegranates and bananas each have over 300 mg of potassium per serving.

Do you want to learn more?

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