A cyst is an abnormal growth consisting of a closed sac filled with fluid or solid material. The material within the cyst is usually produced by the cells that make up the lining, or wall, of the cyst. Cysts form for a variety of reasons, depending to some degree on the tissue involved. Some cysts that form in the adrenal glands are caused by bacterial infections or by parasites.
Some cysts in the brain can cause headaches, as well as other symptoms. Other internal cysts, such as those in the kidneys or the liver, may go unnoticed until an imaging scan (X-ray, MRI scan, CAT scan, ultrasound) detects them.
The most common type of cyst is the sebaceous cyst. Also called epidermoid, pilar, and vulvar cysts, they are harmless, slow-growing bumps under the skin, often appearing on the scalp, face, ears, back of the neck, back, upper chest or groin area (typically the vulva or labia). They are usually rounded, non-tender and of varying size.
Any redness, tenderness, or increased temperature of skin over area may indicate an infection. Grayish white, cheesy material from the cyst (if drained or squeezed) may have a bad odor.
Some doctors believe that a tendency to form cysts occurs more frequently in those with an acidic body pH. If so, an alkalizing diet may help.
Generalized cysts may be due to allergies. Allergy testing may be useful only if there are other allergy symptoms also.
A very large cyst that causes significant symptoms can be surgically removed, or drained by inserting a needle or catheter into the cavity.
Sebaceous cysts are usually ignored unless they become bothersome or infected. An infected cyst can form into a very painful abscess for which surgical incision and drainage is usually necessary for pain relief. Excision of the cyst and the surrounding sac may be necessary to prevent recurrence. Sebaceous cysts may disappear spontaneously, or remain in place without causing any problems.