Inside a cyst is fluid, blood, tissue, sometimes hair, bone or a foreign body depending on the cysts and location of the cyst.
A cyst is basically a pocket like area within tissue which is not normally there.
When a cyst is filled with pus it becomes and abscess.
Most cysts are nothing to worry about and are benign.
Your epidermal cells form the walls of the cyst and then secrete the protein keratin into the interior.
The keratin is the thick, yellow substance that sometimes drains from the cyst.
This abnormal growth of cells may be due to a damaged hair follicle or oil gland in your skin.
Cysts are abnormal, fluid-filled sacs that can develop in tissues in any part of the body.
They are relatively common, and there are many different types.
Infections, tumors, parasites, and injuries can cause cysts and most cysts are usually noncancerous.
Epidermoid cysts often go away without any treatment.
If the cyst drains on its own, it may return.
Most cysts don't cause problems or need treatment.
They are often not painful, unless they become inflamed or infected.
Simply using a warm compress a few times a day for between 10 to 15 minutes can help to reduce inflammation and encourage drainage from the cyst.
Over time, thanks to the drainage, the cyst will simply deform, leaving no trace of it behind.
But some cysts grow painful, and when this happens, it's time to call your dermatologist.
Pain can be an indication that the cyst is infected, in which case it won't go away unless your dermatologist either drains it and injects the area with medication or surgically removes it.