What is hyperhidrosis (hi-purr-hi-DROE-sis)? 
This is a medical condition that causes excessive sweating. The word “hyperhidrosis” means too much (hyper) sweating (hidrosis). Excessive sweating happens when a person sweats more than is necessary. Yes, it’s necessary to sweat. Sweating cools the body, which prevents us from overheating. People who have hyperhidrosis, however, sweat when the body does not need cooling. Many people who have hyperhidrosis sweat from one or two areas of the body. Most often, they sweat from their palms, feet, underarms, or head. While the rest of the body remains dry, one or two areas may drip with sweat. This excessive sweating can interfere with everyday activities. Hands can be so sweaty that it becomes difficult to turn a doorknob or use a computer. Sweat from the underarms often soaks through clothes, causing obvious sweat marks. Because the skin is often wet, skin infections can develop. The good news is that medications and other treatments can control hyperhidrosis.
If you have this medical condition, you may notice:
- Visible sweating: When you are not exerting yourself, do you often see beads of sweat on your skin or have sweat-soaked clothing? Do you sweat when you’re sitting?
- Sweating interferes with everyday activities: Does sweating cause difficulty holding a pen, walking, or turning a doorknob? Does sweat drip heavily on to your papers or computer?
- Skin turns soft, white, and peels in certain areas: Does your skin stay wet for long periods?
- Skin infections: Do you get frequent skin infections on the parts of your body that sweat heavily? Athlete’s foot and jock itch are common skin infections.
Two types of hyperhidrosis
Both types cause excessive sweating, but there are some differences.
- In one or a few areas of the body: “Focal” means that the excessive sweating (hyperhidrosis) affects one or a few parts of the body. The areas of the body most commonly affected are the underarms, hands and/or feet, and forehead.
- On both sides of the body: If the excessive sweating occurs in the underarms, the person usually notices both underarms sweat excessively. The same holds true for the hands and feet.
- After waking up: Sweating may begin soon after the person wakes up, but the person usually does not notice damp sheets or wet clothing unless the room is hot.
- At least once a week: For many people, it occurs much more often.
- This type of hyperhidrosis usually begins when the person is a child or adolescent. Most people who have this type are otherwise healthy. In medical terminology, the word “primary” means that the cause is not another medical condition.
Secondary hyperhidrosis: In medical terminology, “secondary” means that the excessive sweating (hyperhidrosis) has an underlying cause. The cause could be a medical condition or maybe a side effect of taking a medication or food supplement. Medical conditions that can cause excessive sweating include:
- Diabetes
- Frostbite
- Gout
- Injury, such as head trauma caused by an accident
- Menopause
- Obesity
- Overactive thyroid (hyperthyroidism)
- Tumor
If a person has this type of hyperhidrosis, the person may notice:
- The entire body sweats excessively: Sometimes, only parts of the body sweat.
- Sweating occurs during sleeping: If you sweat excessively while asleep, it is important to see a dermatologist to learn why this happens.
Anxiety and embarrassment
Both types of hyperhidrosis can cause people to feel extremely anxious and embarrassed. Students often avoid raising their hand during class. Many teens never date. Adults may hide the sweat stains by wearing layers of clothing or changing frequently throughout the day.