Basal cell carcinoma? Melanoma? Squamous cell carcinoma? Skin cancer goes by many names and is one of the most common cancers in the United States—luckily, it’s also one of the most treatable! No matter which form of skin cancer you spot, the earlier it’s detected and treated, the better. Here’s your guide to the common skin cancers and the difference between melanoma and nonmelanoma types.

Melanoma

Melanoma, like many cancers, gets its name from the cells it affects. This type of skin cancer begins in what are called melanocytes, which make the pigment melanin that gives your skin its coloring. This pigment also protects the deep layers of your skin from the sun’s harmful rays.

Unlike other skin cancers, melanoma can begin nearly anywhere—even on your butt (no matter how much sun it gets) or in your eyes or mouth—and it’s considered aggressive, tending to spread to other parts of your body.

Because of this spreading, or metastasis, melanoma is more deadly than other forms of skin cancer, so be sure to regularly check yourself out this summer! Follow the A.B.C.D. rule to help identify melanoma, looking for these signs: an asymmetrical mark, a mark with an irregular border, or uneven color or a mark that changes diameter, typically increasing to at least the size of a pencil eraser.

Nonmelanoma

Nonmelanoma cancers most often occur as basal and squamous cell cancers, which means they affect the basal cells or squamous cells in the outer layer of the skin. As the most common types of all skin cancers, it’s lucky that they are generally not as dangerous as melanoma.

Basal cell carcinoma usually can be identified as a raised, smooth, pearly bump on the skin, while squamous cell carcinoma is more of a red, scaling, thickened bump that may even bleed—both appear on the head, neck and shoulders where the skin is exposed to sun.

Because these cancers affect the shallower skin cells and rarely spread deeper, they are both more common and less dangerous than melanoma. However, they can still require medical attention once spotted!

In their early stages, skin cancers are almost always curable, especially when they stay in your skin cells without spreading. In order to catch any malignant marks as early as possible, be sure to perform routine self-checks all over your body and ask your doctor about any suspicious spots. You can help prevent melanoma and nonmelanoma skin cancers in a variety of ways. Check out our guide to preventing diseases from the sun!