Next time you hunker down on that bench, consider all the other guys who sweated their way through their workouts there, too.

Along with that pool of perspiration, the other guys could be leaving a host of other nasty things behind. Things like viruses, bacteria, and fungi that can cause some gross, uncomfortable, or even serious skin conditions if they make their way into your body.

Here, 5 nasty skin conditions you can pick up at the gym—and what you need to do to cure them, stat.

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GYM INFECTION: RINGWORM

How you know you have ringworm: Ringworm is shaped like a ring, but it’s not actually a worm, says Joshua Zeichner, M.D., director of cosmetic and clinical research in the department of dermatology at Mount Sinai Hospital.

It’s actually a fungal infection that hits the top layers of your skin, forming a circular, red ring.

It might have an itch, but other than the visible rash, it doesn’t produce any other symptoms.

It can show up anywhere on your body, but typically you’ll find it on your torso, upper arms, or thighs.

How you contract ringworm: The fungus thrives in wet environments, Dr. Zeichner says.

See that sweaty machine? The fungus left from an infected gym-goer may be lurking on the moist surface.

Infection is more likely to occur if you have minor cuts or openings in your skin, but you can still pick it up simply from coming in close contact with a contaminated item—say, by resting your arms or legs on a mat that wasn’t wiped down.

How to treat ringworm: An over-the-counter clotrimazole cream, like Lotrimin will attack the fungus that causes ringworm, says Dr. Zeichner.

If it persists after a week or so, go see a dermatologist. He or she may prescribe a stronger cream.

GYM INFECTION: ATHLETE’S FOOT

How you know you have athlete’s foot: Athlete’s foot is a type of ringworm that develops on your feet, according to the Centers for Disease Control Prevention.

The first sign of athlete’s foot is typically an itch around the soles of your feet, and dry, cracked skin between your toes.

The rash is usually the same color as your skin, and occasionally it can cause itchy blisters, says Jason Reichenberg, M.D., the director of dermatology at the University of Texas Austin.

How you contract athlete’s foot: This type of foot fungus is common in public places like the gym, says he says. Like ringworm, it thrives in moist environments, like locker room showers.

That means your sweaty gym sneakers can actually exacerbate the fungus, too, he says.

If one of other guys at the gym has the infection, takes his sneakers off, and walks around the locker room barefoot, that spreads the fungus. And if you go barefoot in the locker room, the fungus could enter through a break in the skin on your foot and infect you, says Dr. Zeichner.

How to treat athlete’s foot: Over-the-counter sprays can treat this infection—look for Lotrimin, or Tinactin, says Dr. Reichenberg.

These will eliminate it by killing off the fungus cells and leaving the skin cells unscathed.

Just don’t let that annoying itch linger too long before trying the meds: If untreated, the fungus can spread under your toenails and cause a long-term infection, he says.

And play the preventive game: After you walk around the locker room at the end of the day, give each foot a squirt of either one of the over-the-counter antifungal sprays to ward off future infection, he says.

GYM INFECTION: STAPH

How you know you have staph: Staph infections—which are caused by the bacteria staphylococcus—are less commonly picked up at the gym, but can be serious if you do get them, says Dr. Reichenberg.

A staph infection generally looks like a pus-filled or red bump on the skin that grows warm to the touch and becomes swollen, he says.

You may also get a fever, and the area could start to hurt—both signs the infection is spreading deeper in your skin.

How you contract staph: This infection can be transmitted via open cuts and sores on the body, he says, or by sharing your towel or working out on a dirty floor mat.

How to treat staph: Staph infections of your skin—rather than of a hair follicle (see below)—require a visit to your doctor.

He or she will likely send you home with prescription antibiotic creams or pills.

And it’s important you don’t let it go untreated: A type of staph, called MRSA, can be deadly if it enters your bloodstream.

Protect yourself at the gym so you don’t catch it in the first place: Wipe down your mat and your machine before you get started—don’t assume the last guy on it did that when he was done.

Cover any nicks or cuts with bandages and definitely don’t share towels. This limits any opportunity for the infection to enter your body.

GYM INFECTION: FOLLICULITIS

How you know you have folliculitis: Folliculitis—a specific type of staph infection—occurs when bacteria enter your hair follicle’s root and causes inflammation, says Dr. Zeichner.

You’ll likely notice red bumps and pus-filled pimples in hairy areas like your chest or legs, he says.

It can feel uncomfortable and tender, especially if the pimples are large.

How you contract folliculitis: Similar to the fungus with ringworm, the bacteria that causes folliculitis can be left behind on a moist, sweaty piece of equipment.

You’re more susceptible if you have any cuts or nicks in your skin—say, with cracks cased by dry skin— which can give it an easy entryway to your body.

How to treat folliculitis: Dab some OTC Bacitracin ointment directly on to the spot, Dr. Zeichner says. This topical antibiotic will help kill the bacteria.

If it doesn’t show any signs of improvement after a week, head to your doctor. He or she will prescribe a stronger oral or topical antibiotic to wipe out the infection.

Then take stop it from happening again: Avoid shaving before a workout, since bacteria can enter through nicks.

If you do have a wound, bandage it up and cover that area with long sleeves to maximize your skin protection, he says.

You can also lower your risk by washing with antibacterial soap or an acne cleanser with benzoyl peroxide, which should remove the bacteria from your skin.

GYM INFECTION: PLANTAR WARTS

How you know you have plantar warts: Plantar warts—which are caused by humanpapilloma (HPV) virus—look like small, skin-colored bumps speckled with little black dots, says Dr. Reichenberg.

You can get just a single bump, but most of the time they cluster in an area.

They are also typically tender to the touch, and commonly crop up on the soles of your feet or palms of your hands.

How you contract plantar warts: Plantar warts can be contracted by using contaminated gym equipment, he says—another reason to keep those wipes at the ready.

Since the virus thrives in moist places, like athlete’s foot, you can also pick it up by walking barefoot in the locker room.

How to treat plantar warts: Use an over the counter treatment like Compound W that contains salicylic acid, Dr. Reichenberg says.

Apply it on the wart itself, making sure you don’t hit the surrounding skin. That can cause burning and inflammation to your healthy tissue.

If your wart doesn’t disappear after a few months—or if it starts to hurt or spread—loop in your dermatologist.

He or she may use a freeze spray or apply a prescription-grade salicylic acid medicine, both of which will spark your body’s immune system to fight the infection.