What people think it is: In pop culture, warts are literally the opposite of a beauty mark. The easiest way to identify an evil-spirited witch or hag is to look for a smattering of warts. Obviously, you get warts if you are a) a witch b) evil c) hanging out with toads, or d) cursed by the light of a full moon.

What it actually is: All warts are caused by the human papilloma virus (HPV) (yes, that one). There are about 150 different strains of HPV, and while some cause skin cancer, throat cancer, and cervical cancer, many, like the kind that show up on your skin, only manifest as a harmless (albeit unsightly) growth.

How you get it: The HPV virus can only be passed from person-to-person contact or by touching something the germ has contaminated (think: locker room floor, sharing towels or razors) that then gets into the skin.

How you get rid of it: According to Dr. Krant, over-the-counter treatments do a good job of treating common warts (verruca vulgaris) and small plantar warts that occur on the bottom of the feet. Try a salicylic acid product from Curad or DuoFilm. But Krant offers this word of caution: You must be diligent and continue the treatments long after you expect, because most warts take several weeks to a few months to disappear. If your wart doesn't respond to OTC methods, get thee to a dermatologist. "The earlier [warts] are caught, the easier they are to get rid of," says Krant. A derm can freeze, cut off or burn (pass the anesthesia, please) the wart. Prescriptions are also available. One final word: Dr. Krant recommends forgoing at-home treatments if the wart is on your face or genital area. For those, see a dermatologist right away. Random note: The aforementioned wart that plagued the author of this story was frozen and removed. The initial freezing didn't hurt, but it did sting for a few days after. It never came back, so I can do the lotus pose in yoga class without inducing PTSD.

How you prevent it: Wash your hands! All the time. If you work out at a gym, wipe down the equipment before you get your sweat on. If you shower at the gym, wear flip-flops. If you already have a wart, picking at it will make it spread -- not only to other people, but also to other parts of your body.

What people think it is: So you're feeling like a gangsta, and you go to brush your shoulders off. Imagine your surprise when it's not swag that flies off your shoulder, but ... flakes of dry, dead skin. Cue the cringing. Most people assume this is due to a dry scalp or not washing your hair enough.

What it actually is: Dandruff is actually indicative of the opposite of a dry scalp. The organism Pityrosporum ovale, a yeast-like organism present on our heads, feeds on excess oil and dead skin cells, causing the cells to shed more frequently, which results in those pesky flakes. Some people have an inflammatory reaction to the overgrowth of this organism, which causes the redness and itching.

How you get it: While some people have a genetic predisposition to it, Dr. Krant says that anyone can have dandruff.

How you get rid of it: Dr. Krant recommends shampoos that contain pyrithione zinc, selenium sulfide, coal tar, and ketoconazole. "All of these help to kill the organism and reduce the population so there is less to react to," Krant says. She notes that products with hydrocortisone (one-percent solution) or salicylic acid will help with the inflammatory reaction, but will not address the growth of the organism itself. See our list of the 8 Best Dandruff Shampoos to find a reader-recommended product that's right for you.

For a chronic case of dandruff, you may need to see a dermatologist for a prescription and to rule out bigger health problems that dandruff can be a symptom of, such as seborrheic eczema, an autoimmune condition, or Parkinson's Disease.

How you prevent it: Shampooing more frequently can help keep dandruff at bay because the organism that causes it is drawn to oil for its dietary needs. (Ick.)

What people think it is: Personally, the term "foot fungus" brings to mind the sort of sludge that exists at the bottom of my shower drain. I imagine this disgusting concoction seeping its way under my toenails, resulting in a bacteria-fueled, living, breathing fungus that could take over my body and eat my brain in my sleep.

What it actually is: Foot fungus is caused by a fungus that thrives in damp, confined conditions (so my fears aren't too far off the mark). The same fungus causes toenail infection, and Dr. Krant notes that it's easy to keep re-infecting your feet once your nails are infected. The symptoms include itching and scaly skin, especially between the toes. Blisters and cracked heels may also develop.

How you get it: Contrary to popular belief, walking around barefoot may actually prevent foot fungus. The fungus requires a warm, moist environment, such as the inside of a shoe, to thrive. Most people pick it up in communal showers or by using the towel of an infected person, so bring your own flips to the gym.

How you get rid of it: "Over-the-counter treatments have gotten more effective in recent years, and include formerly prescription-strength antifungal creams," says Dr. Krant. Try Funga Soap by Pedifix for foot fungus, which contains antifungal tea tree oil, and Fungi Nail Antifungal Solution for fungus under the nail. Vinegar soaks (made with one part vinegar and two parts water) can also be helpful for 15-20 minutes daily. Dr. Krant warns that many patients underestimate the length of the treatment for OTC products (standard treatment time is around 12 weeks), and stop the medication before the fungus is completely eradicated. If your feet are particularly sore, or if the rash is spreading, Dr. Krant says it may be a bacterial infection or inflammatory condition that can't be treated with OTC creams. If you're in that number, see a dermatologist.

How you prevent it: Dr. Krant recommends keeping feet as dry and sweat-free as possible. Change your shoes and soaks daily, and allow your feet to breathe. If you're prone to foot fungus, or have particularly sweaty feet, use antifungal foot powders in your socks to prevent reinfection.

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What people think it is: A scarlet letter declaring frequent one-night stands with sleazy strangers.

What it actually is: There's a stigma around cold sores, and it's not entirely without reason. Cold sores are most often caused by herpes virus type 1 (usually associated with oral cold sores) but also by herpes virus type 2 (typically associated with genital herpes).

How you get it: "More than half of Americans have had some kind of exposure to HSV1, and about 15 percent to HSV2," says Dr. Krant. Cold sores are not necessarily sexually transmitted. You can get one from sharing lip gloss or beverages, and you can even contract them in utero. It's a person-to-person communicable disease, so if you come into contact with someone who has it, you can catch it.

How you get rid of it: Once you feel a cold sore coming on (most people describe it as a tingling feeling around the mouth), start treatment immediately with an OTC cream, like Abreva or Orajel. "The faster you are able to start some form of treatment, the shorter the duration of the outbreak should be," says Dr. Krant, who notes that if you're already dealing with a full-blown cold sore, there's not much you can do to make it go away faster. She recommends OTC creams or talking to your doctor about a prescription for pills or cream if you get them every once in a while. If you have frequent outbreaks, you can also talk to your doctor about taking a daily dose of oral antiviral pills, which may suppress outbreaks over the long run. But make no mistake -- just because you can't see it doesn't mean it's no longer contagious.

How you prevent it: "The only way to prevent coming into contact with any form of HSV is to assume everyone you might have contact with has been exposed," says Dr. Krant. While you can ask someone if they have HSV, there's a chance they may not know themselves. It's also possible to be exposed to HSV1 and never have an outbreak. The same goes for HSV2, although it's less likely. Dr. Krant notes that stress, lack of sleep, excessive sun exposure, or anything that knocks your immune system can make a cold sore breakout more likely.

What people think it is: Cancer! A tumor! Another head!

What it actually is: Keloid scars are oddly shaped lumps that form in an area of injury. After they form, they continue to grow outside the area of initial injury. Dr. Krant says keloid scars are distinct because they are made of "neoplastic" benign tumor tissue that grows into the shape of large lumps or irregular shapes. These are not to be confused with a hypertrophic scar, which is a thickened, raised scar that can be red or purple, but never grows beyond the original injury site.

How you get it: "The tendency to form keloid scars is largely genetic," says Dr. Krant. Doctors don't really know why some scars form keloids and others do not, but your chances are greater if you have a family history.

How you get rid of it: Both keloids and hypertrophic scars can be flattened and faded with a silicone gel sheet, corticosteroid injections and lasers. However, Dr. Krant warns that while these treatments may work well on hypertrophic scars, a keloid scar may respond the wrong way and grow even more. Yay. Left untreated, keloids may continue to grow over time. Some keloids, like those received from ear piercings, can be cut off completely. If partially cut off or done incorrectly, the keloid, says Dr. Krant, can grow back larger than before. Word of caution: while researching this story, I saw a YouTube video of someone removing their own keloid scar. Do. Not. Do. This. It's a very bad idea.

How you prevent it: If you know you are prone to keloids, just say no to elective surgical procedures (like body piercings or tattoos) -- it's the only way to avoid developing this type of scarring. Short of covering yourself in bubble wrap and living in a padded room, there's no way to avoid them totally.