Epidermoid cysts are common, noncancerous growths that develop beneath the skin. They form when skin cells move deeper into the skin instead of shedding normally, leading to a slow-growing sac filled with keratin. These cysts can appear anywhere on the body but are most often found on the face, neck, scalp, back, and trunk. Epidermoid cysts are usually harmless but …

Cystic fibrosis is a genetic disorder that affects the lungs, digestive system, and other organs. It causes the body to produce thick, sticky mucus that can clog airways and ducts, leading to chronic respiratory infections and digestive problems. Cystic fibrosis is a lifelong condition that usually begins in early childhood. Advances in treatment have significantly improved life expectancy and quality …

A spermatocele is a benign, fluid-filled cyst that develops in the epididymis, the small coiled tube located behind the testicle that stores and transports sperm. It is usually painless and noncancerous and is commonly discovered during a self-exam or routine physical examination. Spermatoceles are generally harmless and often do not require treatment unless they cause discomfort or grow large. Symptoms …

A pilonidal cyst is a round sac of tissue that’s filled with air or fluid. This common type of cyst is located in the crease of the buttocks and is usually caused by a skin infection. Pilonidal cysts are a common condition, with more than 70,000 cases reported in the U.S. every year. But many people feel too embarrassed to …

A pancreatic cyst is a fluid-filled growth on the inside or outside of your pancreas. There are different types, made of slightly different cellular materials. Some types are neoplastic, and others are nonneoplastic. Neoplastic cysts have the potential to become cancerous. Nonneoplastic types don’t. What does a cyst on the pancreas mean? Some pancreatic cysts seem to be related to inflammation (pancreatitis), but most …

Ovarian cysts are fluid-filled sacs that develop on or inside the ovaries. They are common and often form during the menstrual cycle. Most ovarian cysts are harmless and resolve on their own, but some can cause pain, complications, or indicate underlying medical conditions. Ovarian cysts can occur in women of all ages but are most common during reproductive years. Symptoms …

Kidney cysts are fluid-filled sacs that develop on or inside the kidneys. They are commonly discovered incidentally during imaging tests done for other medical reasons. Most kidney cysts are noncancerous and harmless, especially simple kidney cysts, which are the most frequent type. In many cases, they do not interfere with kidney function and require no treatment. Kidney cysts are different …

A ganglion cyst is a noncancerous, fluid-filled lump that commonly develops along the tendons or joints of the wrists, hands, ankles, or feet. It forms when synovial fluid leaks out of a joint or tendon sheath and becomes trapped in a sac-like structure. Ganglion cysts can vary in size and may grow larger with joint activity or shrink over time. …

Cyclothymia, also known as cyclothymic disorder, is a chronic mood disorder characterized by ongoing fluctuations between mild depressive symptoms and periods of elevated mood. These mood changes are less severe than those seen in bipolar disorder but are persistent and can last for years. Cyclothymia typically begins in adolescence or early adulthood and can affect daily functioning, relationships, and emotional …

Cyclic vomiting syndrome is a disorder characterized by repeated episodes of severe nausea and vomiting that occur in a predictable pattern. These episodes are separated by periods of normal health with no symptoms. Cyclic vomiting syndrome most often begins in childhood but can also affect adults. The condition can significantly disrupt daily life and may be associated with migraines and …