Have you ever run a hand through your hair or decided to rock a new style and felt a scalp bump or a lump that wasn’t supposed to be there? Rest assured, most of these risings are harmless, says Hollywood dermatologist Jessica Wu at dailyglow.com. But there are three common bumpy scalp conditions you should know about. Check them out below.

Pilar Cysts
These firm, round lumps vary in size, from small as a pea to big as a tangerine. These cysts can pop up anywhere on the scalp and are usually painless. A cyst is just a sac of oil and dead skin cells accumulated under the scalp. But if left untreated, cysts can grow bigger and eventually press on hair follicles, causing hair loss. If you find one, talk to your doctor about whether removing it is right for you. Removal is usually done under local anesthesia; afterward, the hair grows back.

Seborrheic Keratoses
These gray or beige bumps grow on top of the scalp. They can be smooth or rough and up to the size of a Junior Mint. Brushing and combing can irritate the bumps and make them itch and bleed. These symptoms can also be signs of skin cancer, so if you notice a crusted bump, then have a dermatologist check it out.

Skin Cancer
Skin cancer can appear anywhere, including your scalp. Especially if you spend a lot of time outside or always part your hair the same way (which exposes the same patch of skin all the time). One type of serious skin cancer is called melanoma, which may look like smooth, dark brown or black moles. Another deadly type of skin cancer is a carcinoma, such as basal cell and squamous cell carcinomas. These can appear as scaly scalp risings. So if you notice something like this, see your doctor.

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