Here's why you're getting pimples and red bumps in your armpits.

We don't know who's idea it was to make underarm pimples a thing, but we're not entirely pleased about it. They're annoying, painful and 11/10 of us don't have a clue how to get rid of them or why we're blessed with them in the first place. Gah!

Watch: Are you low-key obsessed with pimple-popping videos? Of course you are! Check out what KdB loves most about Dr Pimple Popper. Post continues below. 

But the thing is, we're constantly putting our pits through a lot of intense sh*t. So it kind of makes sense why the skin in this area freaks out. Between shaving, waxing, laser, tanning, harsh deodorants and random body washes - it's a LOT.

This will often cause your fed up pits to break out in a glorious array of pimples. Or other skin conditions that kinda disguise themselves as pimples when they're actually something separate. Sneaky.

To find out what's causing your underarm pimples and how to treat them, we chatted to skin expert Dr Giulia D'Anna from Dermal Distinction and asked her for some answers

What's causing breakouts under my arms?

So, what's the go with underarm pimples? Are they just popping up cause we're shaving wrong? Or are we doing other stuff that's triggering these pimps and we're just oblivious to it?

Well, according to Dr D'Anna - it's a little from column A and a little from column B. To break things down, we've pulled together some of the most common causes of underarms pimples.

You're using a blunt razor.

You know that disposable shaver you've had in your shower for, like, three months? Yeah, bin it. You need to be real about when your razor is blunt, because other than it having a 100 per cent chance of being rusty and gross, it could be causing major irritation to your skin - particularly your delicate underarms.

The most common issue? Ingrown hairs. "Blunt shavers tend to cut the hair by 'splintering it', so that the hair cannot grow out of the follicle but gets caught under the skin," said Dr D'Anna.

Not only can it cause ingrown hairs, but a bacteria-ridden, blunt razor cut could lead to more generalised infections such as cellulitis. So, make sure you're swapping out your razor on a regular basis to avoid any issues.

"Always use a sharp shaver and don’t store it in the shower where it might get rusty," adds Dr D'Anna. "A great tip is to wet your armpits and apply a mild cleanser before shaving. Try not to press too hard, or you may force bacteria or skin cells into the hair follicles."

You have blocked hair follicles.

At first, blocked hair follicles usually look like breakouts of pimples - but they're actually a little different. Their proper name sounds very complicated and long: hidradenitis suppurativa. Let's just call it HS for short.

Is butt acne your main concern? Listen to Mamamia's podcast for your face, You Beauty, where we talk about how to get rid of those annoying pimples on your bum. Post continues below. 

Over time, HS can become pretty freaking painful, especially if they get infected. 

But, how do they come about in the first place? "Sweat glands can get blocked from dead skin cells building up in the armpit area," explained Dr D'Anna. 

"The underarm area gets exposure to quite a lot of friction as the arms swing back and forth. Whenever skin rubs over skin, it is possible that injury, irritation, and even infection can result as bacteria get stuck in the pores."

HS can sometimes be a difficult concern to treat, but topical prescription treatments or antibiotics can help. If this skin condition sounds familiar, we reckon you should see your doctor and suss out what your options are when it comes to treatments.

You're using roll-on deodorants.

If you're a fan of roll-on deodorants, we have some bad news - they could be causing you to breakout. 

"Deodorants that rub on can clog the sweat gland or hair follicle. This can lead to a build-up of bacteria and dead skin cells in the follicle or sweat gland," said Dr D'Anna. The result? Pimples. Glorious pimples.

Try switching up your deodorant (there are a whole heap of options on the market, including aluminium-free formulas) or just make sure you're giving your underarm a chance to breathe by washing off deodorant before you go to bed.

You're sweating excessively.

If there's one thing that your pits are really good at (besides flaring up with angry red bumps), it's sweating. But if you're sweating more than usual (whether it be due to working out or because it's a thousand degrees outside) and not jumping in a shower and cleaning the area properly, you're more likely to experience infections. 

"Areas of the skin that often become moist are at risk of developing a yeast or fungal infection. Yeast infections frequently produce red bumps or pustules, which are pus-filled red blisters."

Not ideal.

What's the best way to treat armpit pimples?

Okay, friends. Before Googling your symptoms and panicking: IT’S A FUNGAL INFECTION, you should definitely take five and run your eyes through some things Dr D'Anna recommends. 

1. Make sure you cleanse your pits. Like, actually though.

Serious question: Are you washing your pits properly? (Psst... splashing a bit of water under them doesn't count). Dr D'Anna said, "Keep the area cleansed to reduce bacteria. Lots of people forget to clean this area." 

To keep your underarms fresh, clean and pimple-free, shower daily and wash your underarms with warm water and a gentle cleanser.

2. Apply aloe vera.

To soothe the drysies and calm irritation, Dr D'Anna said, "Use aloe vera to soothe the area and keep the skin hydrated, without clogging the skin." 

Aloe vera has anti-inflammatory and antibacterial properties - so she's a real legend when it comes to settling red, rashy, pimple-prone pits.

3. Get out of your sweaty gym clothes ASAP.

Don't go to brunch and then shopping and then day drinks in your sweaty activewear. "Try not to keep sweaty clothes on for longer than needed so that yeasts do not build up. And for the love of god, wash your gym clothes regularly." 

Want more evidence why wearing sweaty gym clothes is gross? We wrote all about it here.

4. Use anti-bacterial soap.

If you need to bring out the big guns, reach for an anti-bactieral soap. "An antibacterial soap, such as a benzoyl peroxide wash, can also help kill the bacteria on the skin. However, this can be very irritating to the skin in some individuals," said Dr D'Anna. 

If you have sensitive skin, this one might not be for you. So, just skip it and stick with the gentle cleanser we discussed in step one.

5. Shave you underarms at night.

Oh, oh! This one's a goodie. Dr D'Anna said to always shave at night, instead of first thing in the morning. "Try shaving in the evening when you are less likely to sweat. Wait until morning before applying deodorant or antiperspirant to reduce irritation."

6. Speak to your doctor.

If you're experiencing issues with bumps under your arms on the regularly, it's probably best to check in with your doctor and make sure everything is okay.

"Don’t be afraid to seek the advice of a doctor to get them looked at too, especially if they recur," said Dr D'Anna. Things like armpit lumps and enlarged lymph nodes are definitely something that you should not ignore.

Feature: Getty

Do you get armpit pimples? Have you tried any of the above treatments? Share with us in the comment section below.