A cyst is a sac-like pocket of membranous tissue that contains fluid, air, or other substances. Cysts can grow almost anywhere in your body or under your skin.
There are many different types of cysts. Most cysts are benign, or noncancerous.
Whether a cyst needs treatment depends on a number of factors, including:
the type of cyst
the location of the cyst
if the cyst is causing pain or discomfort
whether the cyst is infected
If you’re not sure of what your own skin condition is, you can take a picture and send it to an online dermatologist.