Excessive sweating is divided into two categories to help clinicians and sufferers understand their cause, and then approach treatment. The two types of hyperhidrosis are: Primary Focal and Secondary Generalized. Understanding the difference is one of the most important steps in understanding hyperhidrosis.
Primary focal hyperhidrosis refers to excessive sweating that is not caused by another medical condition, nor is it a side effect of medications. The excessive sweating is the medical condition itself. This type of sweating occurs on very specific areas of the body (described as focal areas) and is usually relatively "symmetric" meaning that both the left and right sides of the body are affected similarly. The most common focal areas are the sweaty hands, sweaty feet, sweaty underarms, and sweaty face or head. (Notice that we say 'and' when we list the focal areas? That's because most people with hyperhidrosis experience excessive sweating on more than one area--especially those with sweaty palms, they almost always also have sweaty feet.)
Primary focal hyperhidrosis often begins in childhood or adolescence, especially hyperhidrosis of the hands and feet. Interestingly, although people with primary focal hyperhidrosis have episodes of excessive sweating at least once a week, they usually do not experience excessive sweating while sleeping. It’s also been shown that primary focal hyperhidrosis may be inherited and many members of the same family may suffer from this condition (but sadly many never talk about it with each other because of embarrassment). If hyperhidrosis seems to "run" in your family, you may be able to help researchers better understand who gets hyperhidrosis and why. This is critical research to help us one day find a cure for hyperhidrosis. Make it a monthly habit to visit our current research studies page to find out about important research and participate whenever you can.
Whether you have primary or secondary hyperhidrosis can be determined by asking yourself a few questions as outlined by (and published in the Journal of the American Academy of Dermatology, 2004, Vol. 51, P. 274-86) St. Louis dermatologist Dr. Dee Anna Glaser. Dr. Glaser is the International Hyperhidrosis Society President and founding board member and an internationally recognized expert in hyperhidrosis. First, says Glaser, ask yourself if you have experienced focal visible excess sweat for at least six months without apparent cause. If the answer is "yes," then the next step is determining whether you meet at least two of the following criteria:
- Your sweat is bilateral and relatively symmetrical, meaning you sweat the same on both sides of your body.
- Your excess sweat impairs your daily activities.
- You experience at least one episode a week.
- The onset of your excess sweat is earlier than age 25.
- You have a positive family history. (Meaning that other members of your family suffer from similar sweating problems.)
- You stop sweating when you're sleeping.
If you meet at least two of the above criteria, chances are you have primary focal hyperhidrosis, and you should make an appointment with a dermatologist familiar with treatment options for people with hyperhidrosis. (Check our Physician Finder database for a doctor near you.) Some dermatologists believe upwards of 90 percent of people who present with excessive sweating will be diagnosed with primary hyperhidrosis.
The other main type of hyperhidrosis is referred to as secondary generalized hyperhidrosis. This type of excessive sweating is caused by another medical condition or is a side effect of a medication. That’s why it’s called secondary - it’s secondary to something else. Unlike with primary focal hyperhidrosis, people with secondary hyperhidrosis experience sweating on larger or other areas of the body (described as generalized areas). Another key difference between the two types of hyperhidrosis is that people with secondary generalized hyperhidrosis may often experience their sweating symptoms while sleeping. With secondary hyperhidrosis, excessive sweating usually starts in adulthood, whereas primary hyperhidrosis starts in childhood or adolescence. Finding a potential treatment for secondary excessive sweating often involves first determining what (if any) underlying medical condition or medication may be the root of the problem. In the case of secondary hyperhidrosis, you don't want to eliminate an important symptom of an underlying condition.
As with primary focal hyperhidrosis, it is important to talk to a knowledgeable physician about all-over, secondary sweating. A physician, such as an internal medicine doctor, can look at your medical history, provide an examination, run any necessary tests, consider any medications you may be taking (remember to tell your doctor about all medications you're using - including over-the-counter and herbal/natural products) and provide other professional insights.
If you think you suffer from secondary hyperhidrosis, we've compiled a list of medications that can cause excessive sweating as a side effect, and a list of diseases and conditions that can cause excessive sweating as a symptom. Of course, not everyone who takes one of these medications or who suffers from one of these conditions will experience sweating. The lists are provided as a starting point for a discussion with a physician. Only a knowledgeable physician can diagnosis and treat hyperhidrosis.
Drugs/Medications Known to Cause Hyperhidrosis as a Side Effect (Please note that these medications are listed alphabetically by generic name. The generic name of a medication usually appears in parentheses on its packaging or small print next to its brand name.)
We also provide you with a helpful list of Diseases & Conditions that May Cause Hyperhidrosis so you can see how important it is to fully understand the cause of your sweating.
Much of the information on this site pertains specifically to primary focal hyperhidrosis. If you feel that you suffer from secondary generalized hyperhidrosis, we strongly encourage you to print out the lists above (see links) and use them to help you talk to a doctor about your excessive sweating in order to address its underlying causes.
Do you think you may have primary focal hyperhidrosis? Visit Hyperhidrosis Treatments and get familiar with your choices for managing (or eliminating) your sweating.