Sebaceous cysts are noncancerous bumps in the skin that are partially hardened and packed with blood. A sebaceous cyst may be pea-sized, measuring from one centimetre across, to five centimetres across.
A cyst is a slow-growing mass that can quickly pass under the surface. Under the skin, sebaceous cysts may be found. A sebaceous cyst is most commonly present on the palms of the hands and the soles of the feet.
Sebaceous cysts are caused by clogged glands, trauma, and swollen hair follicles, among other things.
Cysts may be inherited in some cases. A sebaceous cyst usually develops slowly and does not cause discomfort. The overlying skin will become swollen, tender, and painful if the sebaceous cyst becomes inflamed or infected. Sebaceous cysts form on a continuously irritated region. When a cyst becomes corrupted, it drains a cheesy, foul-smelling substance that may be unsightly.