Hyperhidrosis is a condition where the body produces excessive sweat far beyond what it needs to stay cool. This sweating can happen even when a person is resting, in cold temperatures, or during situations that wouldn’t normally cause anyone to sweat. While sweating is a normal and healthy way for the body to regulate temperature, people with hyperhidrosis may find their clothes soaked through or sweat dripping from their hands, affecting their confidence, work, and daily activities.

How Common Is Hyperhidrosis?

Hyperhidrosis is more widespread than many people realize. In the United States, studies suggest that approximately three percent of adults between ages 20 and 60 experience this condition, which translates to about 16.4 million people.^[2][8] In Australia, around four in every 100 people live with excessive sweating.^[3] Despite being quite common, less than half of those affected actually discuss their symptoms with a healthcare provider, often due to embarrassment or the mistaken belief that nothing can be done.^[13]

The condition does not favor one gender over the other, affecting men and women roughly equally, though women are somewhat more likely to seek medical help for their symptoms.^[2][13] For many people, hyperhidrosis begins during childhood or adolescence, particularly the type that affects specific areas of the body such as the palms, feet, or underarms.^[12][15]

What Causes Hyperhidrosis?

The root cause of hyperhidrosis varies depending on which type a person has. In primary hyperhidrosis, the exact reason for excessive sweating remains largely unknown despite extensive research. Scientists believe it involves overactive sweat glands that are triggered by the nervous system even when cooling isn’t necessary.^[2] The body’s normal feedback system that should tell sweat glands when to stop appears to be impaired, allowing sweating to continue unchecked.^[2]

This type of hyperhidrosis seems to have a genetic component. One-third to one-half of people with primary hyperhidrosis report that someone else in their family also has excessive sweating, suggesting that certain genes may be passed down through families.^[1][13] However, researchers have not yet identified exactly which genes are involved or how they cause the condition.^[5]

Secondary hyperhidrosis has clearer causes. This type occurs when excessive sweating results from another medical condition or as a side effect of certain medications.^[2] Medical conditions that can trigger secondary hyperhidrosis include diabetes, overactive thyroid (called hyperthyroidism), menopause, Parkinson’s disease, low blood sugar, some types of cancer, heart conditions, and various infections.^[1][3][8] Medications such as dopamine agonists, selective serotonin reuptake inhibitors (SSRIs), antipsychotics, insulin, and even common pain relievers like naproxen can also cause excessive sweating.^[2][12]

Risk Factors for Developing Hyperhidrosis

Several factors can increase a person’s likelihood of developing hyperhidrosis. Having a family history of excessive sweating is one of the strongest risk factors, particularly for primary hyperhidrosis.^[1][13] If parents or siblings experience excessive sweating, there’s a higher chance that other family members will as well.

Age also plays a role. Primary hyperhidrosis typically begins before age 25, often during childhood or the teenage years.^[12][15] Secondary hyperhidrosis, on the other hand, can develop at any age depending on when the underlying medical condition or medication use begins.

People with certain medical conditions face higher risks of developing secondary hyperhidrosis. Those with diabetes, thyroid disorders, neurological conditions, or who are going through menopause are more likely to experience excessive sweating.^[3] Lifestyle factors such as stress levels, anxiety, and even dietary choices can influence sweating, though these are more likely to worsen existing hyperhidrosis rather than cause it initially.^[13]

Recognizing the Symptoms of Hyperhidrosis

The hallmark symptom of hyperhidrosis is sweating that goes far beyond what the body needs for temperature regulation. People with this condition may sweat so heavily that moisture soaks through their clothing or drips visibly from their hands, feet, or face.^[1] This sweating happens even when the person is not hot, not exercising, and not in a situation that would typically cause perspiration.

For those with primary hyperhidrosis, the excessive sweating usually affects specific areas of the body. The most commonly affected areas are the palms of the hands, the soles of the feet, the underarms, and the face and forehead.^[2][6] The sweating is typically symmetrical, meaning it occurs on both sides of the body equally. For example, both palms will sweat excessively, or both underarms will be affected at the same time.^[13]

The sweating associated with primary hyperhidrosis usually occurs at least once per week during waking hours and often stops during sleep.^[13] Many people find that their symptoms worsen in warm environments or during stressful situations, though the sweating can happen at any time.^[15]

Over time, chronic excessive sweating can lead to additional symptoms. The skin may become irritated, itchy, or inflamed from constant moisture.^[12] The skin on the feet might crack or peel. While the sweat itself from hyperhidrosis doesn’t typically have a strong odor, when bacteria on the skin mix with sweat particles, body odor can develop.^[8][12] Some people also develop fungal or yeast infections in areas where the skin stays wet too often.^[8]

Beyond the physical symptoms, hyperhidrosis can significantly affect a person’s emotional well-being. More than 40 percent of people with this condition avoid certain daily activities or hobbies because of their sweating.^[18] The condition can cause embarrassment, social anxiety, and withdrawal from interactions with others.^[1] Some people feel so uncomfortable that they change their clothing multiple times throughout the day or avoid shaking hands with others.^[6] For young people, excessive sweating that starts in childhood can interfere with school activities and social development, as moist palms make it difficult to hold pencils, handle papers, or participate in activities with peers.^[15]

How to Prevent or Reduce Excessive Sweating

While primary hyperhidrosis cannot always be prevented because its exact cause is unknown, there are several strategies that can help reduce the frequency and severity of sweating episodes. For secondary hyperhidrosis, addressing the underlying medical condition or adjusting medications (under a doctor’s guidance) may help resolve the excessive sweating.

Making thoughtful lifestyle adjustments can make a significant difference. Wearing loose-fitting clothes made from breathable natural fabrics like cotton allows air to circulate and helps moisture evaporate from the skin.^[4][20] Avoiding tight clothing and synthetic fabrics like nylon, which can trap moisture, helps keep the body cooler. Choosing darker colors or busy patterns can help conceal sweat marks more effectively than light or solid colors.^[20] For the feet, wearing socks that absorb moisture and changing them at least twice daily can help, as can alternating between different pairs of shoes to allow them to dry completely.^[4]

Diet also plays a role in managing hyperhidrosis. Certain foods and beverages can trigger sweating episodes. Spicy foods, caffeine, and alcohol stimulate the nervous system and sweat glands, so reducing or avoiding these may help.^[20][21] Staying well-hydrated by drinking plenty of water helps the body regulate its temperature more effectively and may reduce overall sweat production.^[20][21] Eating cooling foods like cucumbers, watermelon, and leafy greens can support the body’s natural temperature control.^[20]

Managing stress and anxiety is another important preventive measure, as emotional stress can trigger excessive sweating. Techniques such as deep breathing exercises, meditation, or other relaxation methods may help reduce anxiety-related sweating.^[21] Some people find that avoiding situations or activities that trigger their symptoms helps them maintain better control.

Practicing good hygiene can prevent complications from excessive sweating. Using clinical-strength antiperspirants, applying them at night when sweat glands are less active, and keeping absorbent wipes or sweat pads on hand throughout the day can help manage moisture and prevent skin irritation.^[20][21]

Understanding How Hyperhidrosis Affects the Body

To understand hyperhidrosis, it helps to know how sweating normally works in the body. The human body contains between two and four million sweat glands distributed across the skin.^[6] Most of these are eccrine glands, which are the type primarily involved in hyperhidrosis. These glands are found throughout the body but are concentrated in areas like the palms, soles of the feet, forehead, cheeks, and underarms.^[2][6]

Eccrine glands produce a clear, odorless fluid that helps cool the body through evaporation. The glands are controlled by the autonomic nervous system, which is the part of the nervous system that regulates involuntary body functions. Specifically, nerve fibers release a chemical messenger called acetylcholine that tells the sweat glands when to produce sweat.^[2][13]

In a normally functioning system, the hypothalamus in the brain detects when the body temperature rises and sends signals through the nervous system to activate sweat glands. Once the body has cooled sufficiently, a feedback mechanism tells the glands to stop producing sweat. The brain has separate pathways for temperature-related sweating and emotion-related sweating.^[5]

In people with primary hyperhidrosis, this regulatory system goes awry. The sweat glands become overactive and respond to stimuli even when cooling is not needed. Research suggests that the problem lies not with the sweat glands themselves, but with how the nervous system controls them.^[5][13] The acetylcholine feedback loop that should turn off sweating appears to be impaired.^[2] This means the nervous system may have a dysfunction in how it regulates sweating, causing hyperactivity of the sympathetic nervous system or abnormal processing of emotional triggers.^[5]

Scientists have proposed several mechanisms that might be involved in this dysfunction. Some research points to structural changes within the autonomic nervous system, while other studies have found increased expression of certain proteins in sweat glands, such as aquaporin 5, which helps transport water.^[5] The exact biological processes and which genes might be responsible remain areas of active research.

In secondary hyperhidrosis, the mechanism is different. Here, an underlying medical condition or medication disrupts the body’s normal temperature regulation or stimulates sweating through other pathways. For example, hormonal changes during menopause can affect the hypothalamus’s temperature regulation, leading to hot flashes and sweating. Thyroid disorders can increase metabolism and body temperature, triggering more sweat production. Some medications directly stimulate the nervous system or sweat glands as an unintended side effect.