Understanding Anhidrosis: Why Can't I Sweat Anymore?

Anhidrosis is a condition in which a person is unable to sweat. This may sound like a convenient thing to some people, but anhidrosis can lead to a host of other complications.

What is sweat?

Before we answer why you can’t sweat, we need to explain what sweat is. Sweating is one of the functions of the skin or integumentary system. Essentially, sweat is essentially water and salt. Aside from these, it also contains traces of other chemicals such as lipids, proteins, sugars, and ammonia.

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Is sweating a good or bad thing?

Even though sweat is not the most attractive thing to have, it is still an important bodily function. It is a natural byproduct of the body. Sweat cools the body down when a person’s body temperature goes up due to fever, exercise, or hot weather.

Sweat is generally good although its reputation, well, rather stinks. It can be considered “bad” for many people because of the smell. However, sweat on its own is essentially odorless. What gives sweat its pungent odor is the ammonia and bacteria from the skin.

What happens if I can’t sweat anymore?

Like all things, too much or too little can be a bad thing. There are two conditions that are related to sweat production. Too much sweating is a disorder called hyperhidrosis. Anhidrosis is the opposite of this condition.

While too much sweat can be annoying and embarrassing, not sweating at all can actually be life threatening. Without it, the body cannot remove excess toxins from the body or cool down. 

Maintaining the normal body temperature is essential for survival. Prolonged exposure to low temperatures can cause hypothermia. While the opposite is hyperthermia. If the body temperature exceeds 40°C for too long, overheating can occur. This can cause heat cramps, heat exhaustion, or heatstroke.

What is the cause of anhidrosis?

Anhidrosis is the inability to perspire. The disorder may occur when a child is born without sweat glands, metabolic disorders, or acquired causes. Other diseases can cause anhidrosis by disrupting the normal sweat glands’ functions.

Some diseases and conditions that can affect sweating:

• Connective tissue diseases (e.g. Sjögren syndrome)
• Psoriasis
• Atopic dermatitis
• Miliaria (heat rash)
• Multiple sclerosis
• Shy-Drager syndrome
• Peripheral neuropathies
• Exposure to toxins

In addition, some common medications that can partially or completely cause anhidrosis as a side effect include Amlodipine, Atropine, Benztropine, Clonidine, Diltiazem, Felodipine, Hyoscine, Nifedipine, Scopolamine, and Verapamil.

What are the signs and symptoms of anhidrosis?

Generalized anhidrosis affects large areas of the body. The lack of sweating usually causes heat exhaustion, heat intolerance, inability to tolerate physical activity, or dizziness. In some cases, anhidrosis can make you less sensitive to pain. 

Segmental or focal anhidrosis can cause excessive sweating in other areas of the body. This is to compensate for the lack of sweat and increased heat build-up. Because there is still partial ability to sweat, heat exhaustion is less likely to occur than with generalized anhidrosis.

How do you diagnose anhidrosis?

A doctor can diagnose anhidrosis through a check up and skin tests. After that, a sample of skin may be taken and examined under a microscope to determine if there are sweat gland problems. However, if the cause is due to a medication, you may need to stop taking it or use a substitute.

To detect anhidrosis, your doctor may request for a thermoregulatory sweat test. Firstly, a special powder is spread on the skin. Next, the patient sits in a warm room or chamber until they start to perspire. Afterwards, the areas of the skin that create sweat will turn purple while areas without sweat will be yellow. 

Humid and hot environments can block sweat glands, resulting in a condition called miliaria. It is also known as heat rash or prickly heat. Heat rash appears as small vesicles (similar to pimples or whiteheads).

What is the treatment of anhidrosis?

Unlike hyperhidrosis or excessive sweating, anhidrosis has limited treatment options. Because overheating is the most dangerous complication, patients with anhidrosis should avoid hot and humid environments. Most importantly, staying hydrated and in an air-conditioned room can help control your body temperature. In addition, clothing should also be lightweight and breathable to prevent heat retention. Lastly, using a spray bottle or drinking cool beverages without caffeine can safely lower your body temperature.

Fortunately, small areas of anhidrosis may not need treatment, however, wider areas may be dangerous. At this time, there are no drugs or surgeries available to cure it. Addressing the underlying cause may reverse anhidrosis, in many cases.

Moreover, anhidrosis caused by heat rash does not need treatment. Usually, heat rash or prickly heat clears up on its own within 2 to 3 days. If you think that you may have miliaria or anhidrosis, contact your doctor or dermatologist for a consultation.

Key takeaways

In summary, anhidrosis is the inability to sweat. Currently, there is no cure or medication available to effectively treat it. If you find yourself asking, “Why can’t I sweat anymore?,’ or feel hot after light activity, you should seek medical attention.

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