What Your Sweat Can Tell You About Your Health

Your sweat is doing more than cooling you down — how much of it there is, how it smells, and how salty it gets can all hint at what’s going on inside.

When’s the last time you truly tuned into your body and thought about all the signals it sends you every day? It’s easy to take them for granted, but they mean something. Goosebumps tell you you’re cold, itchiness can mean your skin is dry, and, of course, sweating usually means your body is trying to cool down.

Sweat is one way your body helps you survive, and there’s a lot that your sweat can reveal about your health. How much you sweat, how it smells, and even how salty it is can offer clues about whether you’re too hot, stressed, underhydrated, or low on sodium. The next time you work up a sweat, don’t just shrug it off as an annoying bodily function. Pay attention to what your body might be trying to tell you.

What You Should Know

Sweat is the result of millions of glands releasing a bodily brew of roughly 99% water and 1% electrolytes, including sodium and chloride. Your body starts producing sweat when it heats up, which helps cool you back toward your normal body temperature. Stressful situations — think anything that triggers your fight-or-flight response — can also cause you to sweat.

The universal truth is that just about everyone sweats when they’re hot or stressed (with some medical exceptions). Beyond that, there can be considerable variation in how much you sweat based on your genetics, environment, age, body size, and fitness level. Those patterns, along with certain characteristics of your sweat, can offer clues about what’s going on in your body. But if you suddenly start sweating much more or less than usual, or if something about your sweat concerns you, consult a doctor rather than trying to diagnose yourself.

Going Deeper: What Different Kinds of Sweat May Mean

The act of sweating is fairly straightforward, but your sweating habits can offer some insight into why your body is reacting the way it is.

If You Sweat a Lot

Usually, sweating a lot simply means you’re in a hot environment, exercising at a moderate-to-high intensity, dealing with stress, or have consumed a lot of caffeine. In these situations, your body is doing what it’s supposed to do: trying to cool you down.

Hormonal changes during pregnancy, perimenopause, and menopause can also increase sweating. And if you regularly sweat heavily without an obvious trigger, you may have a condition called hyperhidrosis. Night sweats are also worth mentioning to your doctor if they regularly soak your clothes or bedding, especially if they occur alongside a fever or unexplained weight loss.

Your Sweat Smells Strongly

Different sweat glands produce different types of sweat. The sweat your body produces to cool itself comes mostly from eccrine glands, which are spread across nearly all of your skin. Apocrine glands, concentrated in areas like your armpits and groin, produce a thicker fluid containing proteins and fats. When bacteria on your skin break down those substances, they can create the odor you associate with sweat.

Strong-smelling sweat usually isn’t cause for concern. But persistent body odor that doesn’t improve with regular hygiene can, in some cases, be associated with medical conditions such as diabetes, or liver or kidney disease. If you notice a lasting change in how you smell without an obvious explanation, talk to your doctor.

Your Sweat Is Salty

If sweat regularly stings your eyes or leaves white streaks on your skin or clothes, you may be losing more sodium through your sweat. This is especially relevant during long or intense workouts, when replacing fluids and electrolytes can help replenish what you’ve lost. In rarer cases, unusually salty sweat traces back to certain medications or a condition like cystic fibrosis.

Pay attention to how you feel, too. Symptoms such as nausea, vomiting, headache, confusion, weakness, or muscle cramps can signal hyponatremia — dangerously low blood sodium — and warrant a call to your doctor.

If You Hardly Sweat

Not sweating much — or at all — can sometimes be a sign of dehydration. It can also be caused by anhidrosis, a condition in which your body doesn’t produce enough sweat.

The bigger concern is when you can’t sweat properly while your body is overheating, since sweating is one of your primary ways of cooling down. Heat stroke doesn’t always come on fast, either — it can build over a few days, and it’s more likely in adults over 65. If you’re hot but not sweating and develop symptoms such as dizziness, confusion, a rapid pulse, or a high body temperature, seek medical attention. If you consistently sweat very little even when you’re well hydrated and should otherwise be sweating, bring it up with your doctor.

The Takeaway

You can’t and shouldn’t avoid sweat, but wearing breathable clothing, managing your stress, and drinking fluids throughout the day keep it manageable and healthy. If you notice that you’re sweating a lot from heat or exercise, consider replenishing your electrolytes with a supplement. And stay aware of how much you’re sweating, its smell, and whether it tastes salty or not. If you’re unsure about anything, just play it safe and reach out to your doctor. 

Bottom Line

Your sweat can tell you more than you might think. Changes in how much you sweat, how it smells, or how salty it is can offer clues about your hydration, hormones, stress levels, and, occasionally, an underlying health condition. Most sweating is perfectly normal, though, so think of these signs as clues about what’s happening in your body, not a diagnosis.

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