A cyst is a closed capsule or sac-like structure, usually filled with liquid, semisolid, or gaseous material. Cysts usually occur within almost any type of the body’s tissue; they vary in size from microscopic to large structures that can displace internal organs. Although cysts can also refer to any normal bag or sac formation in the body, in this article, we will use the definition stated above and consider it to be an abnormal formation. Consequently, the cysts discussed below are not normal parts of the body. They have distinct membranes or cyst walls. If the sac is filled with pus, it is usually considered an abscess.
The risk factors for a cyst depend on the underlying cause. Genetic conditions, defects in developing organs, infections, tumors, and any obstructions to the flow of fluid or oils or other substances are risk factors for cyst development.
The majority of small cysts have no symptoms or signs. However, sometimes these can be felt as a lump or bump in the skin or even in the tissues beneath the skin. Sometimes these cysts are painful. Cysts not associated with the skin but with internal organs may not produce any symptoms if they are small. If the cysts become large and displace or compress other organs or block normal fluid flows in tissues like the liver, pancreas, or other organs, then symptoms related to those organs may develop.
The type of doctor that treat cysts depend on the underlying cause of the cyst and the symptoms, if any, that are produced by the cyst. Usually a primary-care doctor is the first one who should be consulted when you notice a cyst. For example, a small epidermoid cyst that causes no symptoms would not require treatment. However, a large cyst in the abdomen displacing internal organs would require a surgeon to remove it. Consequently, many different physician specialists may be involved (OB/GYN, surgeon, orthopedic, gastroenterologist, ENT, dermatologist, infectious disease, or oncologist, for example) depending on the cyst’s size, location, composition, and underlying cause.