A photo guide to all the random-ass bumps on your body

Let a bump go rogue for too long and you could even be dealing with Dr. Pimple Popper-level stuff. (Shudder.)

Use this photo guide to decode the bumps on your bod—and decide whether you need to head to the dermatologist, stat.

1) Keratosis Pilaris

What is it: "Keratosis pilaris causes skin-colored or red bumps, usually on the upper arms and legs," says Debra Jaliman, M.D., author of Skin Rules: Trade Secrets From a Top New York Dermatologist. "The skin usually feels very rough, like sandpaper."

Why you have it: This pesky skin condition is triggered by a buildup of keratin, which is a protein that protects your skin from harmful substances and infection. "Because the skin doesn't exfoliate normally, the excess keratin blocks the pores, which results in tiny bumps," says Jaliman.

Treatment: Use a sonic cleansing brush (like the Clarisonic Mia 2), which gently speeds up the exfoliation process, and moisturizers with exfoliating lactic or salicylic acid (since dry skin tends to make the condition worse).

2) Cherry Angiomas

What are they: “Cherry angiomas are harmless red bumps that can develop anywhere on the body,” says Joshua Zeichner, M.D., director of cosmetic and clinical research at Mount Sinai Hospital. They're make up of dilated blood vessels.

Why you have them: Usually, it comes down to genes. But sometimes they'll increase in number and size during pregnancy and other times when your estrogen is very high.

Treatment: Thankfully, they’re not usually dangerous. Your dermatologist can cosmetically remove them with lasers or other instruments in the office.

3) Dermatofibromas

What are they: "These pink-brown, hard bumps in the skin are technically a type of scar," says Tsippora Shainhouse, M.D., a board-certified dermatologist in Beverly Hills. They can appear anywhere on the body, but most often show up on the legs and arms.

Why you have them: "They're often the result of an ingrown hair, bug bite, or other skin trauma and sometimes pop up during pregnancy," Shainhouse says.

Treatment: They don't need to be removed but can be if they make you feel uncomfortable. "If you have many dermatofibromas, see your dermatologist to make sure that you don't have an underlying, predisposing condition that's causing them," says Shainhouse, such as lupus.

4) Keloids

What are they: "Keloids are thick, hard lumps of scar tissue that occur at the site of skin trauma, but instead of limiting themselves to the precise scar line, they extend way beyond it, involving healthy skin," says Shainhouse. They can be itchy and tender.

Why you have them: They often form after skin injuries from acne, chicken pox, piercings, C-section scars, and even minor scratches. Zeichner says that while anyone can get them, they tend to be more common in patients with darker skin tones.

Treatment: Sometimes, they become smaller over time, but if not, there are a number of treatment options, including freezing, laser treatments, steroid injections, and topical silicone, says Shainhouse.

5) Moles

What are they: Okay, you know this one. "These are brown spots on your skin that are made up of clumps of skin cells that contain melanin," says Shainhouse.

Why you have them: Genetics (you're born with tiny ones that grow!), and sun exposure. Light-skinned people tend to have more of them.

Treatment: You can leave them alone - but monitor new and unusual-looking ones since they could be cancerous. (In which case, go straight to your derm!)

6) Lipomas

What are they: A lipoma is a noncancerous, fatty lump that feels doughy to the touch and can move around with slight finger pressure, says Shainhouse. They can crop up anywhere on the body that has fat, but they're not attached to the underlying fat layer or to the overlying skin.

Why you have them: Lipomas tend to be genetic. They aren't linked to being overweight, or gaining weight, and they don't shrink if you shed pounds.

Treatment: They're typically harmless, but they can become painful if they grow and press on nearby nerves. Your best option is to have it removed, says Shainhouse.

7) Folliculitis

What is it: "Folliculitis is an infection of the hair follicles," says Jaliman, and it looks like a small white bump. "It’s common in areas where there excessive sweating, such as the buttocks, and many people confuse this for acne on their rear end," says Zeichner.

Why you have it: It's caused by too much bacteria on the skin, such as when you skip a shower post-workout or stay in sweaty clothes for too long. "I've also seen it from people who don't shave properly," adds Jaliman. If you use a dull razor or shave without shaving cream, you could be putting yourself at risk.

Treatment: Folliculitis can be treated with a topical antibiotic (or pills in severe cases).

8) Skin tags

What are they: “Skin tags are fleshy bumps that typically occur around the neck and under the arms,” says Zeichner.

Why you have them: It generally comes down to genetics, although it's still unclear why exactly they happen. However, being overweight and having diabetes may increase your likelihood of developing skin tags.

Treatment: “They’re harmless, but if they get large, they may get in the way of your undergarments or jewelry,” says Zeichner. Speak to your dermatologist about having them professionally snipped off. (And please, don't rip skin tags off yourself!

9) Seborrheic keratoses

What are they: “Seborrheic keratoses are skin-colored or brown, warty bumps that typically develop on the chest, back, extremities, and around the bra line,” says Zeichner. They’re harmless, although in some cases, may become large, itchy, and inflamed.

Why you have them: It's generally just something that happens when you get older. “Some describe them as barnacles that grow on the skin with age,” says Zeichner.

Treatment: Your dermatologist can freeze them off using liquid nitrogen, or you can try a new, FDA-approved treatment on the market called Eskata.