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The sweat glands in your body produce sweating and body odor. Your skin has two types of sweat glands: eccrine and apocrine.
Eccrine glands cover most of your body and open directly onto the surface of your skin. These glands release fluids on the surface of your skin to cool you down as they evaporate. On your palms and soles, the purpose of these glands is to prevent them from flaking or hardening so they can receive sensations.
Apocrine glands develop in areas where you have hair like the scalp, armpits, and groin. These glands release a small amount of milky, viscid fluid milky fluid—pale gray, whitish, yellow, or reddish—when you feel stressed. This fluid is odorless until it mixes with the bacteria on your skin, creating an odor.
As part of the endocrine system, the thyroid gland produces hormones that regulate the body's metabolism. Your body processes slow down and change when your thyroid hormone production drops, affecting virtually every system in the body.
In people with hypothyroidism, symptoms related to skin tissues are expected. A primary complaint is of dry or coarse skin. This dryness is often due to decreased sweating, though the exact connection between the thyroid and sweat glands is unclear.
It's common to experience some level of body odor while sleeping. Most people only apply antiperspirant or deodorant in the morning, and it wears off throughout the day. Then, after we sleep and sweat through the night, our perspiration causes a foul smell upon waking.
While hypothyroidism does not directly cause sour-smelling sweat at night, an underactive thyroid may affect other functions that can. Ahead, some of the contributing factors of sour-smelling sweat at night:
Perspiration and bacteria
Bacteria generally cause sour-smelling sweat. Everyone has bacteria on their skin, and when the bacteria start to break down the sweat, it creates an odor. If you run hot at night, causing sweating, try reducing your room temperature or wearing cooler clothing.
Dietary habits could also cause sour-smelling sweat at night. Body odor can result from eating garlic, onion, spicy foods, curry, or drinking alcohol. However, these are not the only foods that may cause sour-smelling body odor. To determine if your diet is the culprit, keep a food journal to track what you ate against your symptoms.
Mineral deficiencies, particularly zinc, may cause body odor. Zinc plays an essential role in healthy liver function, responsible for removing toxins from the body's blood supply. A zinc deficiency may affect the detoxification process, resulting in body odor. Thyroid hormones are essential for zinc absorption, so an underactive thyroid (hypothyroidism) that produces too few thyroid hormones may result in a zinc deficiency.
The thyroid gland is a part of the body's endocrine (hormone) system. When the thyroid gland is overactive, it produces too much thyroid hormone. The higher levels of thyroid hormones speed up many body functions, leading to symptoms like weight loss, nervousness, and excessive sweating. If you sweat more, you may also be likely to smell more.
Hypoglycemia (low blood sugar)
Hypoglycemia is the case of low blood sugar. When blood sugar levels drop, this can cause several sleep-disturbing symptoms like headaches and excessive sweating. Some research indicates that blood sugar imbalances are common in people with Hashimoto's hypothyroidism. People with Hashimoto's may be prone to a spike in blood sugar after a high-carbohydrate meal, leading to low blood sugar levels (reactive hypoglycemia).
Menopause and perimenopause can lead to hot flashes and night sweats. Night sweats is a term for sweating during the night to the point that it soaks your sheets or pajamas.
Hot flashes are usually caused by changing hormone levels before, during, and after menopause. Research suggests that hot flashes happen when low estrogen levels cause the hypothalamus (your body's thermostat) to become more sensitive to changes in body temperature.
Another hormonal shift that may cause night sweats is pregnancy. Over a third of women during pregnancy and the postpartum period report experiencing hot flashes.
In men, a drop in testosterone may contribute to night sweats. Low testosterone may result from factors like:
- Injury or infection of the testicles
- Tumors or other diseases affecting the pituitary gland
- Some chronic diseases like type 2 diabetes, kidney disease, or cirrhosis
- Some genetic conditions like hemochromatosis, myotonic dystrophy, Klinefelter syndrome, Kallmann syndrome, and Prader-Willi syndrome
- Certain medications, chemotherapy, or radiation treatments
Idiopathic night sweats
Suppose you rule out all other potential root causes or conditions. In that case, your doctor may determine that you have idiopathic night sweats, meaning no known cause.
Now, with an understanding of common reasons for night sweats, we look at how to get rid of sour-smelling sweat at night.
Lower the temperature in your room
To make sleep more comfortable, keep your bedroom at a cooler temperature to provide ventilation and minimize sweating. Turning on a fan or opening a window may also help with circulation.
Wear cool, breathable pajamas
Wear loose-fitting, sweat-wicking pajamas, or skip them altogether. If you find you also struggle with cold intolerance, consider wearing layers to bed that you can easily remove.
Sleep under thin sheets
Consider using sheets or blankets that are not cotton. Try thin fleece blankets and silk or satin bed sheets. These fabrics don't trap as much heat, allowing for more air circulation and less sweating while you sleep.
Take a cold shower
Taking a cold shower before bed is a great way to lower your body temperature and cleanse your body of bacteria that could lead to sour-smelling sweat. Washing with an antibacterial soap bar may help get rid of some bacteria, too.
Avoid odorous foods
Foods like garlic, onion, spicy foods, curry, or drinking alcohol can contribute to sour-smelling sweat. Avoid them altogether, or consider eating them earlier in the day to reduce your nighttime odor.
Eat a nutrient-dense diet
Increasing your intake of certain nutrients helps you reduce odors. Load up on nutrient-dense foods like leafy green vegetables, fiber-rich foods, and citrus fruits.
Balance your blood sugar
Low blood sugar may contribute to excessive sweating. Stabilize your blood sugar overnight. Eat a meal with protein and fat at dinner, avoid sweets, refined carbs, and alcohol, and take a spoonful of coconut oil or MCT oil right before bed.
Manage your stress
Stress and anxiety can lead to a sweaty night's sleep. To mitigate racing thoughts, decrease caffeine, take coconut oil, or unplug for an hour before bed. Keep a pad of paper with a pen next to your bed. Write down your thoughts so you can address them the next day. Place your hands on your belly, breathe deeply, scan your body, and tense and release the muscles.
Share in the community what you do about stinky sweat:
A note from Paloma Health
You can take a thyroid hormone blood test to understand how your thyroid functions and determine if there is a need for further evaluation to find a solution to your sour-smelling sweat.