Underarms: Everyone has 'em, but nobody really likes to talk about 'em. Why not? Talking brings you knowledge, and knowledge is power, so let's discuss some of the common questions you have about your armpits. Here, four doctors have lots to say.1. Why do we sweat?
First off, there actually two different kinds of sweat glands that produce two different kinds of sweat, says Kenneth Howe, M.D. at Wexler Dermatology. "Most of the sweat glands on our skin are eccrine glands, which control our temperature and are present all over our body," Howe explains. "They produce a watery, odourless perspiration that evaporates on the surface of our skin, cooling our body when it's hot."
The other type of sweat glands are the apocrine glands, and its purpose is a little less clear. "Most scientists feel that the purpose of apocrine sweat is to act as a pheromone—that is, the smell they give off can act as a sexual attractant, territorial marker, or warning signal." Who knew your sweat was so smart?2. How do I know if I'm sweating too much?
If your sweating is interfering with your quality of life, you're not alone: Howe notes that almost 3% of the U.S. population suffers from excessive perspiration, with "half of those cases affected in the armpits." Yikes! While many of those cases are idiopathic—there isn't an underlying medical cause—he says it can be hereditary, too.
Howe explains that this condition, known as axillary hyperhidrosis, is diagnosed when excessive, visible sweating has been going on for at least 6 months without an apparent cause, as well as the presence of at least two of the following characteristics:
- Sweating affects both underarms equally.
- Sweating impairs daily activities.
- At least one episode occurs per week.
- The excessive sweating begins before age 25.
- A family history of the problem exists.
- The perspiration stops during sleep.
If two of more of these symptoms are applicable to you, and your sweating is impeding your life, talk to your doctor for potential solutions.
As for odour: Your body is not totally odourless—a little scent is perfectly natural. But if you're starting to feel like your personal, ahem, fragrance is scaring people away, talk to your doctor about potential solutions.3. Okay, but how can I stop sweating?
First, try conservative treatments like deodorants and antiperspirants. "When over-the-counter antiperspirants are not enough, a doctor can prescribe a stronger one" says Howe. "This product contains a higher concentration of aluminum chloride, making it more effective than over-the-counter picks—but it can also be much more irritating."
If those aren't effective enough, there are more drastic alternatives. "Some patients require oral medications such as anticholinergic drugs, but these have side effects like dry mouth and blurry vision," explains New York City dermatologist and RealSelf contributor Michele Green, M.D.. Iontophoresis machines, medical devices which use electric currents to curb sweating, have also been utilised but need to be repeated daily or weekly.
For folks who aren't afraid of needles, there's Botox, which is now approved by the U.S. Food and Drug Administration for the treatment of excessive sweating. "Botox injections are used to disable the sweat glands by blocking the release of acetylcholine, shutting down the sweat process in any site that is injected," explains Green. The effects can last from 6 to 12 months, depending where it's injected.
Another new treatment: miraDry, a procedure done at a doctor's office that takes about an hour. "MiraDry uses microwaves to treat the sweat glands of the armpit," says Howe. Local anesthesia is usually injected into the area prior to treatment, but there can be swelling or tenderness in the area afterward.
Other patients seek more natural solutions to their sweating, such as chamomile, valerian root, sage root, St. John's Wort, acupuncture, or relaxation treatments. Talk to your doctor to determine the best route for you.
4. Why is the skin on my underarms dark?
If you've noticed your underarm skin is a bit darker than the surrounding areas, you could be affected by acanthosis nigricans. "This condition can cause darkening in the body, including the underarms," explains San Diego dermatologic surgeon and RealSelf contributor Sabrina Fabi, M.D.. "It causes a thickening of skin, which makes the skin look darker, but it's not necessarily because the skin cells are darker." This is typically seen in patients who are overweight or pre-diabetic due to an increased presence of a hormone called insulin, which also stimulates the growth of skin cells. If you're experiencing underarm darkening and you're not overweight, Fabi adds that it can also be genetic and seen in patients who are totally within their ideal body weight.
Other possible causes for underarm darkening: Eczema, obesity, fungal infections, hormones, and certain medications can be to blame, says Green. "Excessive exposure to UV light can encourage melanocyte cells to produce the melanin that makes your skin darken, too," she adds.5. Why do we have underarm hair?
It does have a purpose! "Underarm hair reduces friction between the upper and lower arm during vigorous labor or motion, covers exposed parts of the body with vital arteries, and facilitates the release of sex pheromones," explains Marta Camkiran, esthetician at Haven Spa.
6. So...do I need to shave it?
Nope. "There is no medical necessity to shave your underarms," says Green. If you choose to shave 'em, that's totally fine, but don't let anyone tell you that it's unhealthy or unclean to let that hair grow.
"There's this false association that hairlessness equals cleanliness, but that's not actually true as long as you're clean," says dermatologist Mona Gohara, M.D.. "Men wear deodorant, have underarm hair, and don't smell—there's no biological reason women can't do the same." Simple as that.7. Is it okay to share razors?
If you do opt to shave, there are some big no-nos you need to keep in mind. First of all, never share razors with other people. Not even if you forgot yours, not even if you two are best friends, not even if it's just once. "It's bad enough that your personal blade is harbouring your own dead skin cells and bacteria—why introduce someone else's sloppy seconds as a risk factor for infection?" says Shereene Idriss, M.D., of Wexler Dermatology.8. Why do I have a rash on my armpits?
Speaking of shaving, those little bumps under your arms could be caused by some bad razor behavior. First, make sure to change your blades regularly. "Old blades can harbour bacteria, which can lead to skin infections or folliculitis," warns Idriss. Dry shaving is another underarm "don't," as it can cause superficial nicks, cuts, and irritation (a.k.a. razor burn). Be sure to clean the blade between passes, too, to ensure it's nice and clear—not clogged with skin cells, hair, shaving mousse, and so on. The cleaner the blade, the slower it will get dull.
On top of your basic shaving mistakes, there could be more sinister causes for your rash. Green cites dermatitis, psoriasis, intertigo, candidasis, and folliculities as potential culprits—you could even be allergic to your deodorant or soap. Talk to your doctor if you have a rash that just isn't going away.
Yes. "Among the laundry list of things it can be, a lump in your underarm can be as benign as a cyst, to a red flag for infections, or cancer presenting itself as an enlarged lymph node," warns Dr. Indriss. Better safe than sorry—get checked ASAP!
This article originally appeared on GoodHousekeeping.com. Minor edits have been made by the Cosmo.ph editors.