Excessive Sweating Affects up to 5% of People

Petra Meciarova, a dermatologist at the F.D. Roosevelt University Hospital and Polyclinic in Banska Bystrica, Slovakia, says hyperhidrosis is diagnosed when the body produces more sweat than it needs to control its temperature and the problem begins to affect a person’s quality of life.

"Warning signs include, for example, sweating at rest and for no apparent reason, regularly soaked clothing, the need to change one’s shirt several times a day, sweat dripping from the palms or difficulty shaking hands, writing, using a phone or choosing clothes", she says.

Hyperhidrosis affects an estimated 3% to 5% of the population. Meciarova points to a large US study that put the figure at 4.8% – almost one person in 20.

"The actual number may be higher, as many cases remain undiagnosed. People are often embarrassed and don’t know that effective treatment exists. This condition is not a sign of poor hygiene and can significantly impair one’s professional, social and romantic life", she says.

There are two main forms of the condition. Primary hyperhidrosis typically affects both sides of the body symmetrically, occurs at least once a week and often begins before the age of 25. It can run in families and usually stops during sleep.

Sweating that starts suddenly, affects the whole body or continues at night, however, may point to a secondary cause.

The armpits, hands, feet, face and scalp are most commonly affected. These areas have a high concentration of sweat glands, whose activity is strongly influenced by the nervous system.

"In primary hyperhidrosis, excessive nervous stimulation may be limited to specific areas. Some people therefore sweat mainly on their hands and feet, while others are affected primarily in the armpits or face. A combination of sweating on the hands and feet is common. Whole-body sweating, especially if it begins suddenly in adulthood or continues during sleep, is more indicative of a secondary form of hyperhidrosis", Meciarova explains.

Sweating More Does Not Always Mean Something Is Wrong

Not everyone who sweats heavily has an underlying health problem. Some people naturally sweat more than others. Genetics, body type, fitness, hormones and sensitivity to heat or stress can all make a difference.

With primary hyperhidrosis, there is no underlying illness. Instead, the nervous system sends an unnecessarily strong signal to the sweat glands even when the body does not need cooling. The condition often begins in childhood or adolescence and can run in families.

Secondary hyperhidrosis has another cause. It can be linked to illness, hormonal changes or medication, tends to appear later in life and is more likely to affect the whole body, including during sleep.

A sudden unexplained change in sweating is therefore worth paying attention to, particularly if other symptoms appear at the same time. Meciarova says possible causes include thyroid problems, diabetes, hormonal changes during menopause, infections and certain neurological or cardiovascular conditions. Some medications and withdrawal symptoms can also trigger excessive sweating.

When Should You Worry About Night Sweats?

Waking up drenched in sweat can be alarming, particularly when it happens repeatedly. But occasional night sweats do not necessarily mean something is wrong.

"If the bedroom is too warm, we’re using a thick blanket, we’ve had alcohol, eaten spicy food or are going through a stressful period, occasional sweating at night doesn’t necessarily mean there’s a medical condition", Meciarova says.

Night sweats are also common during menopause and periods of anxiety, as well as with low blood sugar or as a side effect of certain medications.

They become more concerning when someone repeatedly wakes with pajamas or bedding so wet that they need to change, despite sleeping at a comfortable room temperature. If this happens regularly or becomes progressively worse, medical advice should be sought.

Food, Alcohol and Stress Can Make It Worse

What we eat and drink can also affect how much we sweat. Spicy or hot food, alcohol, caffeine and very hot drinks are common triggers.

"For some people, sweating can also be made worse by chocolate, acidic foods or large portions. However, the reaction varies from person to person", Meciarova says.

A simple diary noting what you ate or drank and when the sweating became worse can help identify individual triggers.

Medication can play a role too. Some antidepressants, pain relievers, hormone therapies and drugs used to treat high blood pressure or diabetes can cause excessive sweating.

Then there is stress. Strong emotions can make sweating considerably worse, particularly on the hands, feet, underarms and face.

"People start to worry that they’ll sweat, which increases their anxiety and makes the sweating even worse. It creates a vicious cycle", Meciarova explains.

Over time, that cycle can take a toll on confidence, relationships and social life.

From Antiperspirants to Botox

People whose sweating interferes with everyday life have several treatment options. For milder cases, the solution may be as simple as finding the right antiperspirant.

Meciarova stresses the difference between deodorants and antiperspirants. Deodorants primarily tackle odor. Antiperspirants contain aluminum salts that temporarily block the ducts of the sweat glands, reducing perspiration.

"Over-the-counter products from drugstores generally contain lower concentrations of active ingredients. Antiperspirants from pharmacies may contain, for example, 15% to 20% aluminum salts and are more effective, but they can also be more irritating to the skin", she says.

How they are used matters. Antiperspirant should be applied in the evening to completely dry, unbroken skin and washed off in the morning. It should not be used immediately after shaving. Treatment may initially involve applying it for several nights in succession before switching to less frequent maintenance use.

If antiperspirants are not enough, other treatments are available. Botulinum toxin type A – better known as Botox – is not only a cosmetic treatment. It can also be used to treat hyperhidrosis by temporarily blocking the nerve signals that activate the sweat glands.

It is most commonly injected into the underarms, where the effect typically lasts seven to nine months, but it can also be used on the hands, feet and some areas of the face.

For more severe cases, dermatologists may recommend iontophoresis, medication or procedures that target and destroy or remove sweat glands.

Surgery is generally reserved for cases in which other treatments have failed. The most radical option is endoscopic thoracic sympathectomy, which involves cutting or clipping part of the sympathetic nerve chain in the chest.

"It achieves the best results in cases of severe palmar hyperhidrosis that does not respond to standard treatment. However, it is an invasive procedure, and there is a risk of compensatory sweating, in which excessive sweating may shift to other parts of the body. Sympathectomy is therefore considered only as a last resort", Meciarova says.