A chlorine-like smell on your skin usually comes from ammonia, a nitrogen-containing compound your body produces naturally and releases through sweat. Ammonia has a sharp, chemical odor that many people describe as smelling like chlorine, bleach, or a swimming pool. In most cases, the cause is something ordinary like diet, dehydration, or a hard workout. Less commonly, it can signal that your kidneys or liver aren’t filtering waste properly.
How Sweat Produces a Chlorine Smell
Your sweat itself is mostly odorless when it first reaches the skin’s surface. The smell develops when bacteria on your skin break down sweat components into volatile molecules, including ammonia and short-chain fatty acids. Eccrine sweat, the type produced all over your body for cooling, naturally contains small amounts of ammonia. Apocrine sweat, concentrated in your armpits and groin, becomes odorous only after bacteria like Corynebacteria and Propionibacteria go to work on it.
Ammonia is a byproduct of protein metabolism. When your body breaks down amino acids for energy, it produces ammonia as waste. Normally, your liver converts most of that ammonia into urea, which your kidneys then flush out in urine. But when ammonia production is high or your body is low on other fuel sources, more of it escapes through your sweat, and you notice that sharp, pool-water smell on your skin.
Common, Non-Serious Causes
High-Protein Diet
Eating a lot of protein gives your body more amino acids to break down, which means more ammonia as a byproduct. If you’ve recently increased your protein intake, switched to a low-carb or ketogenic diet, or started using protein supplements, your sweat may carry a stronger chemical odor. When carbohydrates are scarce, your body turns to protein for energy more aggressively, and ammonia output rises.
Dehydration
When you’re not drinking enough water, your sweat becomes more concentrated. The same amount of ammonia in less fluid produces a noticeably stronger smell. This is one of the most common explanations, and it’s also one of the easiest to fix. If your urine is dark yellow, you’re likely dehydrated enough for it to affect how your sweat smells.
Intense Exercise
During prolonged or intense exercise, your body can burn through its glycogen (stored carbohydrate) reserves and begin breaking down protein for fuel. This ramps up ammonia production significantly. Endurance athletes and people doing long, hard workouts often notice a chlorine-like smell on their skin or clothing afterward. The effect is stronger if you exercised in a fasted state or without enough carbohydrates beforehand.
Bacteria and Skin Chemistry
Everyone’s skin hosts a unique mix of bacteria, and that mix affects how your sweat smells after it’s been broken down. Some people’s skin microbiome produces more ammonia-heavy byproducts than others. Tight, non-breathable clothing can trap sweat against the skin and give bacteria more time to work, intensifying the smell. Areas with more sweat glands, like the armpits, groin, and feet, tend to be the strongest sources.
When It Points to Something Medical
A persistent chlorine or bleach-like body odor that doesn’t respond to hydration, dietary changes, or hygiene changes can sometimes reflect an underlying organ problem. The two most relevant conditions involve the kidneys and the liver, both of which are responsible for clearing ammonia and other nitrogenous waste from your blood.
Kidney Disease
Your kidneys filter urea, the end product of ammonia processing, out of your blood and into your urine. When kidney function declines, urea builds up in the bloodstream, a condition called uremia. That excess urea can escape through your skin and breath, producing a bleach-like or ammonia smell known clinically as “uremic fetor.” In advanced cases, urea crystals can even deposit on the skin’s surface as a white or yellowish powdery coating called uremic frost, typically visible on the face, neck, and limbs.
Other signs of kidney trouble include foamy urine, swelling in the ankles or feet, persistent fatigue, changes in how often you urinate, and nausea. If the smell has appeared alongside any of these symptoms, it’s worth getting your kidney function checked with a simple blood test.
Liver Disease
Your liver is the organ that converts ammonia into urea in the first place. When liver function fails, ammonia and other toxins accumulate in the blood because they’re no longer being processed effectively. This can produce a chemical odor on the breath and skin. Ammonia contributes to this, though other compounds like trimethylamine and ketones also play a role. If toxin levels climb high enough, they can begin affecting the brain and nervous system, causing confusion and disorientation.
Liver-related body odor changes typically come with other noticeable symptoms: yellowing of the skin or eyes, dark urine, abdominal swelling, easy bruising, or chronic fatigue.
How to Reduce the Smell
If the cause is dietary or related to hydration, the fix is straightforward. Drink more water throughout the day, especially before and during exercise. If you’re on a high-protein or low-carb diet, adding some carbohydrates before workouts gives your body an alternative fuel source and reduces ammonia output through sweat.
Showering soon after exercise helps remove ammonia before bacteria amplify the smell. Wearing breathable, moisture-wicking fabrics reduces the amount of sweat sitting on your skin. Antibacterial soap in high-sweat areas like the armpits can also reduce the bacterial load responsible for breaking sweat into odorous compounds.
If you’ve addressed hydration, diet, and hygiene and the smell persists for weeks, or if it appeared suddenly without an obvious explanation, a basic metabolic panel (a routine blood draw) can check your kidney and liver function and either rule out or catch a problem early.