You make have noticed that sometimes your sweat smells like vinegar or ammonia. This unpleasant sweat vinegar odor has a few different causes and can be a little offputting for some.
Types of sweat glands
Our body has two different types of sweat glands that have two different functions. Apocrine and eccrine sweat glands are found in different parts of the body and have different functions.
Eccrine sweat glands
Eccrine sweat glands are located throughout the body are the sweat glands that help cool the body during exercise or hot temperatures by excreting mostly water with some sodium and other electrolytes.
Apocrine sweat glands
Apocrine sweat glands are mostly limited to the axilla (armpits), groin and eyelids and secrete a thicker sweat than the eccrine sweat glands. The sweat from these apocrine sweat glands contain more byproducts mixed in with the sweat The bacteria on the skin near the apocrine sweat glands can breakdown these byproducts to propionic acid, which is responsible for the vinegar smell in sweat.
Causes of sweat smelling like vinegar
Dietary causes of vinegar smelling sweat
Low-carb and higher-protein diets like the paleo and the ketogenic diet can cause sweat that smells like vinegar as the body breaks down proteins as an energy source due to the lack of carbohydrates in the diet. However, a well-formulated ketogenic diet should not be excessively high in protein since the focus of a ketogenic diet is on a higher intake of healthy fats, with only a moderate amount of protein.
There are several medical problems that can cause sweat smelling like vinegar. Diabetes, kidney and liver problems can all result in a noticeable change in body odor.
Poorly controlled diabetes can lead to a serious medical condition called diabetic ketoacidosis. While diabetic ketoacidosis is not the same as nutritional ketosis, the hallmark of diabetic ketoacidosis is a fruity or vinegar smell on the breath or sweat.
A strong body odor or smell may also represent an underlying liver problem. Severe liver disease often presents with abdominal pain, jaundice (yellowing of the skin and eyes), or fluid in the abdomen (ascites). But sometimes a strong vinegar or ammonia odor can also be a sign of liver problems (1)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1419608/ as the body excretes excess ammonia or methanethiol.
Chronic kidney problems can impact how your body is able to excrete waste products and as the kidney’s ability to filter these waste products decreases, the body will try to excrete them in either in your sweat or thru breathing.
Problems with your thyroid, like hyperthyroidism can also cause a strong odor that is more noticeable when you sweat.
Triimethylaminuria is a rare genetic disorder where the body can’t break down certain chemicals such as trimethylamine. Instead, the body will excrete the excess chemicals in either sweat, urine or breath. The chemical has a “fishy” odor or smell, which is why the condition is sometimes called Fish Odor Syndrome. The condition is worsened by eating foods high in trimethylamine such as eggs, fish and legumes. (2)https://rarediseases.info.nih.gov/diseases/6447/trimethylaminuria
Hygiene issues can result in a build-up of bacteria on the skin and this increase in bacteria can also cause a strong vinegar odor, especially in hot and humid conditions.
How to fix sweat smells like vinegar
Sometimes changes in diet can help decrease the vinegar smell, while for others, trying to limit the amount they sweat can be another way of fixing the vinegar odor issue.
If you continue to notice a strong vinegar smell in your sweat after making diet changes, see your doctor to rule out underlying medical issues like diabetes, thyroid, liver or kidney problems.