Question

I have two bumps at the back of my head. They recently appeared, but I hadn't bumped my head. The one on the left side is a bit larger. They both hurt when touched. What do you think they are?

Answer

What you describe is very similar to sebaceous cysts.

A sebaceous cyst is a catch-all term for a harmless growth that occurs under the skin and tends to be smooth to the touch. Ranging in size,sebaceous cysts are usually found on the scalp, nape of the neck, face, ears, and the genitals.

Sebaceous glands are numerous in these areas, secreting an oil (sebum) that lubricates the skin. Cysts form when the release of sebum, a medium-thick fluid, is blocked.

Unless they become infected and painful or large, sebaceous cysts don't require medical attention or treatment, and usually go away on their own. However, if they are tender to the touch they could be engorged with sebum or infected.

If this happens, antibiotics may be prescribed, or surgical incision and drainage may be needed for pain relief. Excision of the cyst and the surrounding sac may be done to prevent recurrence. However, sebaceous cysts may disappear spontaneously, or remain in place without causing any problems.