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We’ve all experienced body odor after strenuous exercise, waking up, or even while completing daily activities. Sometimes, we reach for deodorant or perfume to freshen things up. Masking odors might mean overlooking signals that could be linked to health issues.
What if these smells are trying to tell us something about our health? Ahead, we will examine whether sour-smelling sweat can indicate a thyroid disorder.
Sweat or perspiration is a clear liquid produced by sweat glands. The human body has three types of sweat glands:
- Eccrine glands are the most numerous, covering your palms, soles, and hairless areas. They produce the most sweat, which is composed primarily of water and salt. Sweat from this gland helps regulate your body temperature in a process known as thermoregulation.
- Apocrine glands are found in areas with hair, such as the scalp, armpits, and groin. They secrete a milky, sticky fluid of lipids (fats), proteins, sugars, and ammonia. Secretion from these glands doesn’t begin until puberty. Apocrine glands, also known as scent glands, are mainly responsible for producing body odor.
- Apoeccrine glands have features of both eccrine and apocrine glands. These glands are in regions where you have hair and produce water-based salty sweat.
You may have also heard of sebaceous glands. They are commonly thought to be a type of sweat gland, but they are not. Sebaceous glands are on the scalp, forehead, face, and genital region and are often located next to sweat glands. Interestingly, secretions from sebaceous glands affect the composition of the sweat on the skin. As we will learn shortly, the composition of sweat can influence its smell.
Sweat has an essential role in regulating our body temperature. Our bodies constantly generate heat from internal metabolic processes, physical activity, or exposure to external environmental factors. When we sweat, we are activating our body’s natural cooling system.
When our body temperature rises due to physical activity, hot weather, or a fever, the brain signals the eccrine sweat glands to release sweat to the skin’s surface. Sweat is primarily made up of water and some minerals, such as sodium and potassium. As the sweat evaporates into the air from our skin, it absorbs heat from the body, helping to cool down our body temperature. This evaporative cooling process helps regulate our body’s internal temperature and prevent overheating, allowing us to perform physical activities and maintain proper bodily functions. You can think of sweat as your natural AC cooling system!
Besides thermoregulation, sweating may also play a role in
- Getting rid of waste products by bringing them to your skin’s surface
- Hydrating the skin
- Improving microbial defenses
We have already mentioned one of the big triggers: body temperature changes. But there are other reasons you may find yourself sweating.
The body may sweat in response to factors such as physical exertion, pain, sexual arousal, certain medical conditions, medications, or hormonal changes.
Sweating is also an emotional response and can be triggered by stress, anxiety, and intense emotions. This type of sweating stimulates sweat release from all areas of the body. Researchers link emotional sweating with a decrease in sleep and relaxation.
Have you ever eaten a spicy meal and immediately started sweating? This type of sweating is known as gustatory sweating or gustatory hyperhidrosis. This sweating is caused by a malfunction in the autonomic nervous system, which regulates sweating. When a person with gustatory sweating consumes certain foods -- usually spicy or hot foods -- their nerve signals get crossed, causing their sweat glands to become overactive. This reaction increases internal body temperature, causing sweat on the face, scalp, or neck.
Sweat is odorless when released from sweat glands. However, when sweat mixes with bacteria on the skin, an odor can develop. The makeup of the bacteria on your skin and sweat determines the smell emitted. Sweat odors can range from pleasant ones, like tropical fruit, to unpleasant ones, such as rotten fish, or cheesy, foul odors.
Sweat from the eccrine gland is primarily water and salt. Still, other nutrients such as potassium, calcium, and magnesium are also mixed in. However, there are non-nutrient components that also make up sweat. These components include urea, lactate, and ammonia. Different factors such as hydration status, alcohol intake, exercise intensity, and clothing choices can affect sweat makeup or rate.
As part of the endocrine system, the thyroid gland produces hormones that regulate the body’s metabolism, among many other functions. A disruption in the balance of thyroxine (T4) and triiodothyronine (T3) thyroid hormones can lead to a cascade of changes in the body. One noticeable change is the regulation of body temperature and sweat production.
In hypothyroidism, thyroid hormone levels decrease, slowing body processes. Because of this, cells don’t generate heat effectively, causing the body temperature to drop. This is why people with hypothyroidism are generally intolerant to cold temperatures.
To compensate for a lower body temperature, you may put on extra blankets or another layer of clothing when you go to bed. And all these additional layers may prevent the evaporation and cooling process from occurring as the body tries to thermoregulate. As a result, you may have excessive sweating at night. Depending on the composition of your sweat, you may also have a noticeable odor when you wake up.
In comparison, hyperthyroidism, an overactive thyroid, speeds up your metabolism. As a result, those who are hyperthyroid generate extra heat, causing excessive sweating throughout the day. This is because the body is trying to maintain its core body temperature. Hyperthyroidism may also change the makeup of sweat, resulting in different body odors as it mixes with bacteria on the skin.
It’s common to experience some level of body odor while sleeping. Most people only apply antiperspirant or deodorant in the morning, which wears off throughout the day. Then, after we sleep and sweat through the night, our perspiration causes a foul smell upon waking.
While thyroid disorders don’t directly cause sour-smelling sweat at night, a change in thyroid hormone production can impact the rate of sweating. In turn, more sweat can result in body odor. Besides a thyroid disorder, other contributing factors to sour-smelling sweat include:
- Diet and Hydration: Your diet and hydration levels can affect your body odor. Consuming certain foods like garlic, onions, spicy foods, and processed foods can release volatile compounds through sweat, causing unpleasant smells. Additionally, inadequate hydration can concentrate toxins in the body, leading to more pungent sweat.
- Poor Hygiene: Poor hygiene is one of the most common reasons for sour-smelling sweat at night. Not showering before bed or wearing dirty or unwashed clothes can lead to the accumulation of bacteria on the skin, resulting in foul-smelling sweat.
- Hormonal Changes: Hormonal changes can also contribute to sour-smelling sweat at night. During menopause, for example, fluctuations in hormone levels can cause night sweats, which may result in odorous perspiration. Metabolic changes in blood sugar levels can also trigger sweating.
- Medications and Medical Conditions: Some medicines, such as antidepressants or antibiotics, can alter the body’s natural odor. Certain medical conditions, like diabetes, kidney or liver problems, and metabolic disorders, can also affect the scent of sweat. These conditions may increase the concentration of chemicals in sweat, leading to an unpleasant smell.
- Stress and Anxiety: Stress and anxiety can impact the production of sweat and its odor. When you are stressed or anxious, your body releases stress hormones like adrenaline, which can trigger excessive sweating and contribute to foul-smelling sweat.
- Excessive Alcohol or Drug Consumption: Alcohol and drug use can impact the body’s metabolism and alter the composition of sweat. Both alcohol and drugs can be released through sweat, resulting in a distinct odor.
Now, with a better understanding of why we sweat, here are some tips to help prevent sour-smelling sweat at night.
Lower the temperature in your room
To make sleep more comfortable, keep your bedroom cooler to provide ventilation and lessen sweating. Turning on a fan or opening a window may also help with circulation.
Maintain good hygiene practices
Showering regularly and washing your clothes and bedding frequently can help reduce sweating and body odor.
Wear cool, breathable pajamas
Wear loose-fitting, sweat-wicking pajamas, or skip them altogether. If you also struggle with cold intolerance, consider wearing layers to bed that you can easily remove.
Sleep under thin sheets and blankets
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
A cold shower before bed is a great way to lower your body temperature. Use a low pH or antibacterial soap to help cleanse your body of bacteria that could lead to sour-smelling sweat.
Avoid odorous foods
Foods like garlic, onion, spicy foods, or curry can contribute to sour-smelling sweat. Avoid them altogether, or consider eating them earlier in the day to reduce your nighttime odor.
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, and avoid sweets, refined carbs, and alcohol right before bed.
Manage your stress
Stress and anxiety can lead to a sweaty night’s sleep. To mitigate racing thoughts, decrease caffeine or unplug for an hour before bed. Keep a pad of paper and a pen next to your bed to write down your thoughts. This will get them out of your head so you can address them the next day.
Limit alcohol and drug consumption
Cutting back on alcohol and drugs can help minimize their impact on sweat odor.
Remember, while occasional night sweats and sour-smelling sweat may be normal, persistent or severe night sweats accompanied by other symptoms should be evaluated by a healthcare professional to rule out any underlying medical conditions.
For those grappling with a thyroid disorder and body odor, it’s crucial to adopt a proactive approach to the issue, which can contribute to a more healthy lifestyle and less risk of body odor from sweat. One way to do this is by optimizing thyroid function. Generally, this is done through medications, lifestyle adjustments, or a combination of both.
But, before you can even talk about treatment options, the first step is knowing your thyroid hormone levels. This can be done from the comfort of your home using Paloma’s convenient at-home testing kit. Our testing kit measures the three most common thyroid biomarkers - TSH, T4, and T3 - used to diagnose or manage thyroid disorders. So, take the first step in optimizing your thyroid health: order your thyroid testing kit today.