A cyst is a small, balloon-like swelling anywhere in the body. A cyst may contain air, fluid, or solid content contained within a sac. Usually, cysts are harmless, but they may be removed surgically if they cause discomfort or distress.

A ganglion is a non-cancerous cyst filled with a thick, jelly-like fluid. Ganglions can develop on or beneath the surface of the skin, most likely on the hand or wrist, although runners and skiers often develop them on the foot.

A ganglion is a non-cancerous cyst filled with a thick, jelly-like fluid. Ganglions can develop on or beneath the surface of the skin, most likely on the hand or wrist, although runners and skiers often develop them on the foot.
Illustration by Electronic Illustrators Group. © 2016 Cengage Learning®.

Where Are Cysts Found in the Body?

Cysts may develop in many areas on the inside or outside of the body. They may be found in the mouth around a developing tooth, in the skin around a hair follicle or sweat gland, in other glands, in the spinal cord, in the liver, in bone tissue, in ovaries * , and in other parts of the body.

Cysts are cavities that are lined with epithelium. Epithelium is a common tissue in the body, which is part of the skin and also serves as a covering for organs and as a lining for vessels and other cavities throughout the body. Cysts form most often when fluid in a gland * becomes blocked in the ducts or tubes leading out of the gland. Sometimes cysts develop because the glands are overactive and produce more fluid than the tissues can absorb. Another cause of cyst formation is the presence of parasites in vital organs, such as the liver or brain.

What Are the Different Types of Cysts?

Cysts are classified mainly by their location in the body. Some of the most common are:

Cysts are also associated with polycystic kidney disease and bilateral cystic mastitis. In the first, numerous fluid-filled cysts form in the kidneys, a condition that can sometimes lead to kidney failure. The second is a much more common disease. In cystic mastitis (also known as Von Schimmelbusch's disease), cysts form in the breast and may be tender especially just before a woman has her menstrual period, but they are not dangerous to her health. Sometimes they can, however, be a health hazard because they may make it more difficult for the woman or her doctor to check the breasts for other unusual growths.

How Are Cysts Treated?

Most cysts do not need treatment. Those that may require treatment are cysts that have become painful, have formed on visible parts of the body such as the hand or around the ears, or have become infected. An infected cyst may contain pus, in which case it is technically known as an abscess. A doctor can remove a cyst by drawing out the fluid with a needle and syringe (aspiration) or by surgically removing it. Surgery is more effective. When the fluid is removed with a needle, the cyst has a tendency to return. Sometimes cysts disappear without any treatment.

With brain cysts, the type, size, and location of the cyst determines the treatment. For arachnoid cysts doctors may wait and see if it grows; it may require surgery. For colloid cysts surgery is the usual treatment; however, this can be challenging because of its location. For both dermoid and epidermoid cysts surgery is the usual treatment; however, if the cyst cannot be completely removed it may grow back.

“Bible Bumps”

Ganglion cysts of the wrist used to be called “Bible bumps.” The home remedy for ganglion cysts once was to rupture them by hitting them with a big book. Many people had only the Farmers' Almanac and the Bible in the home, and because the Bible was the bigger book, it was used to break the cyst.

See also Abscesses • Fibrocystic Breast Disorder • Ovarian Cysts • Tumor


Books and Articles

American College of Obstetricians and Gynecologists. “Ovarian Cysts.” (accessed December 1, 2015).


MedlinePlus. “Cyst.” U.S. National Library of Medicine. (accessed December 1, 2015).


American Brain Tumor Association. 8550 W. Bryn Mawr Ave., Suite 550, Chicago IL 60631. Toll-free: 800-886-2282. Website: (accessed December 1, 2015).

American Society for Surgery of the Hand. 822 W. Washington Blvd., Chicago, IL 60607. Telephone: 312-880-1900. Website: (accessed December 1, 2015).

National Breast Cancer Foundation. 2600 Network Blvd., Suite 300, Frisco, TX 75034. Telephone: 972-248-9200. Website: (accessed December 1, 2015).

* ovaries (O-vuh-reez) are the sexual glands from which ova, or eggs, are released in women.

* gland is an organ that produces substances such as hormones and chemicals that regulate body functions.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)