Cysts, which are small to large bumps that can contain fluids, gas or air, can occur on the skin, or in many different parts of the body. Most cysts are benign, but there are some that require medical attention, as they can be dangerous. In general, the cysts that fall into the danger category are those affecting major organs, or those that affect the breasts. Any lump in the breast could be a cyst, but might also be a cancerous lesion and needs immediate medical attention to rule out cancer.

Cysts can form on the ovaries, in the kidneys, on the esophagus, and in the pancreas. In general these cysts are not cancerous. However, they can affect function of these organs. Evidence of these cysts often requires either removal of, or careful observation of the cysts.

Cysts also form in the lungs of those with cystic fibrosis. In these cases, such cysts are dangerous, since they can severely inhibit breathing. They also render people more vulnerable to lung infections.

A large cyst on the ovaries can rupture, destroying the ovary in the process. This can mean reduced ability to conceive since women are only relying on one ovary. Often frequent incidences of cyst occurrence on the ovaries are treated with birth control pills. These tend to repress cyst production.

Cysts in the esophagus are usually not dangerous, but they can affect speaking and singing. Frequent development of these cysts, or larger cysts may require surgical removal. Some cysts in the pancreas can be cancerous. If noted, they are tested, and may be removed if they interfere with pancreatic function.

Many people have small cysts in their kidneys. These again are likely to be benign, but if they grow large, they may need to be removed. Cysts may also grow in between the joints and may require removal if they become large, unsightly or painful.

Some cysts are evidence of conditions that can be dangerous. For example, exposure to giardia often results in small cysts being passed in the stool of those infected. This parasite can actually pass on to other people through contact with the cysts, which protect and keep alive the giardia.

Cysts on the skin are usually not dangerous, but again may require removal if they become too large. Also a ruptured cyst can become infected and might require treatment with antibiotics. If a cyst ruptures and appears painfully sore, or hot, it may be evidence of skin infection, and one should seek medical attention as soon as possible.