What Is Axillary Hyperhidrosis? Causes of Extreme Armpit Sweating—and Possible Solutions
You're dressed for the day, but it'll only be a matter of time before your armpit sweat seeps through your shirt, forcing you to do a quick change. That's what it's like when your underarms sweat excessively, a condition known as axillary hyperhidrosis.
While it's necessary to sweat to cool down your body, over-the-top sweating can seriously disrupt a person's daily activities.
Adam Friedman, MD, professor of dermatology at George Washington University School of Medicine and Health Sciences in Washington, DC, explains that excessive sweating is defined as four times the amount of sweat needed to regulate your body temperature.
"We need to sweat. It's our body's natural air conditioning system. However, hyperhidrosis is sweating that is not in response to heat; it's not there to cool you down; rather it's an abnormal amount of sweating for no rhyme or reason," Dr. Friedman tells Health.
For example, he says people with hyperhidrosis may be sitting in an air-conditioned room watching a relaxing movie and experience excessive sweating. "It's too much of a needed good thing. It's well beyond what your body needs to be cool, which is why it is a true medical condition," says Dr. Friedman.
What to know about sweat glands
According to the International Hyperhidrosis Society (IHS), there are between two and four million sweat glands throughout the body, and most are found in the soles of the feet, palms of the hands, forehead and cheeks, and, yes, the armpits (or axillae).
The majority of these glands are "eccrine" sweat glands, which release odorless, clear fluid that help cool the body. The type of sweat produced from the eccrine glands is what most often occurs in hyperhidrosis.
What is axillary hyperhidrosis—and what causes this condition?
Excessive underarm sweating not caused by another medical condition is referred to as primary axillary hyperhidrosis. While doctors do not know exactly what causes it, they understand how it occurs in the body.
"What's happening is the nerves that sends signals to the sweat glands [which tell them] to sweat are overactive," says Dr. Friedman.
Your sweat glands respond to various stimuli, says the IHS. These include:
- signals from your brain that your body is overheating
- physical activity or exercise
In people with hyperhidrosis, the sweat glands overreact to these messages by overproducing sweat, says the IHS.
Dr. Friedman notes that hyperhidrosis runs in families, yet scientists have not identified which genes are associated with the condition.
Who develops axillary hyperhidrosis?
Most people with underarm sweating begin experiencing it after puberty, during adolescence or in their early teens, and typically before age 25, says Dee Anna Glaser, MD, dermatologist at SLUCare Physician Group in St. Louis.
"If I have a 60-year old patient who all the sudden starts to sweat all over their underarm, that's not typical of hyperhidrosis, so then we start to think about whether or not something else going on," she tells Health.
While some people who have axillary hyperhidrosis may only have excessive sweating in their underarms, others may have hyperhidrosis that affects other parts of their body, such as the hands, feet, face, scalp, or groin, says the IHS.
Other signs of primary hyperhidrosis include:
- Excessive sweating at least once a week over at least a six-month period
- Sweating on both sides of the body (meaning not just one underarm, but both)
- Sweating so much that it affects your daily activities
When Dr. Glaser is determining a diagnosis, she'll ask the patient if their armpit sweating stops when they sleep. The reason? "People with primary hyperhidrosis don't sweat at night," she says. If someone is sweating profusely from their armpits day and night, that's a sign they don't have primary hyperhidrosis. Their sweating may be due to an underlying medical condition or a drug they't taking—and that's known as secondary or generalized hyperhidrosis.
Does generalized (aka secondary) hyperhidrosis cause armpit sweating?
Most people who sweat excessively from their armpits have primary hyperhidrosis, but it's also possible for people to develop sweaty armpits due to generalized (aka secondary) hyperhidrosis.
"Both primary and secondary hyperhidrosis can lead to axillary hyperhidrosis," Elizabeth Jones, MD, an assistant professor in the Department of Dermatology and Cutaneous Biology at Thomas Jefferson University Hospital in Philadelphia, tells Health.
With secondary hyperhidrosis, armpit sweating is usually bilateral, says Dr. Jones, "but some people tend to sweat more on one side and so many notice it more in one armpit."
Axillary hyperhidrosis treatment
There are a variety of treatments for axillary hyperhidrosis, per the IHS.
"If you ever hear 'don't worry about it, there's nothing we can do about it, it's not going to kill you,' go get another doctor's opinion," Dr. Glaser advises, because excessive sweating can impact your life socially, emotionally, and physically. She says a dermatologist can work with you to find the best treatment option.
Because antiperspirants are the least invasive and are inexpensive, they are often the first type of treatment doctors will use to treat axillary hyperhidrosis, says the IHS. When antiperspirant is applied, the sweat in that area grabs onto it, pulling antiperspirant particles into the pores under the skin. This causes the sweat ducts to "plug," which tells your brain to stop sending messages to sweat in that area.
Botox (onabotulinumtoxinA) is approved by the US Food and Drug Administration (FDA) to treat primary axillary hyperhidrosis, if antiperspirants are not effective. These injections can temporarily block the release of the chemical that initiates the body's sweat glands. "By blocking, or interrupting, this chemical messenger, botulinum toxin 'turns off' sweating at the area where it has been injected," per the IHS. "Botox injections are very shallow, meaning that the medicine is injected just below the surface of the skin, where it remains."
While the IHS says the effectiveness of laser treatment for underarm sweating has not been proven in large studies, some doctors do offer it. Lasers can target and destroy sweat glands in the underarm through small incisions. The procedure usually takes less than an hour to complete.
MiraDry is FDA-approved device to treat axillary hyperhidrosis. It uses microwave technology to destroy sweat glands in the underarm without damaging the skin. Because sweat glands tend to not grow back, the treatment can improve the condition right away, says the IHS. While one treatment is sometimes enough, some people benefit most from a second procedure, three months after the first.
Prescription medications taken by mouth can help stop the sweat glands from producing sweat. Anticholinergics, such as glycopyrrolate, oxybutynin, benztropine, propantheline, are the most common oral medication used for hyperhidrosis, notes the IHS. However, while FDA approved, these medications have not been studied in controlled clinical trials specifically for hyperhidrosis. Still, "dermatologists use off-label medications often," says Dr. Friedman.Just be aware that these medications can cause side effects such as dry mouth, muscle cramps, and urinary retention.
Beta blockers (propranolol) and benzodiazepines are also options for treating excessive sweating. These drugs block sweating that occurs due to anxiety-provoking situations, says the IHS.
Qbrexza is FDA approved to treat axillary hyperhidrosis. These cloths are used once per day on the underarm and work by blocking receptors that activate sweat glands. The active ingredient is an anticholinergic called glycopyrronium tosylate. Applying this medication topically instead of taking it orally may help reduce side effects, says the IHS.
Underarm surgery can also be an option for treating axillary hyperhidrosis, says the IHS. Common techniques include:
- Excision, which involves cutting out sweat glands.
- Curettage, in which sweat glands are scraped out.
- Liposuction, involves suctioning out sweat glands.
Doctors may use different combinations of each surgery. Because these surgeries permanently remove or damage sweat glands, they can have long-lasting effects. However, sweat glands are very small and often undetectable even with instruments, leaving doctors unaware of how many glands they affected.
There's another option, too. It's called endoscopic thoracic sympathectomy (ETS) surgery, but the IHS cautions that it's invasive and poses serious complications. It involves destroying the nerve paths on the spinal column that are connected to the overactive sweat glands. Most physicians do not recommend it, says the IHS.
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