A cyst is a growth covered in a membrane. Generally, cysts grow on the surface of organs or in the spaces between the muscle and skin tissues. Most cystic growths are considered harmless and self contained. These are either filled with infected fluids, air, or semi-solid substances like sebum.
A cyst can happen due to a number of factors. A defect during the development of the fetus can be a cause for a cyst. It can also be caused by an infection. There are also cysts that develop for reasons that are unknown. Patients will usually feel small and hard lumps on their forearms or wrists and are a form called a sebaceous cyst. A lump that is found on the wrist could be another type called a ganglion cyst. There are some people who will have a cyst grow on their vocal cords.
Cysts are not necessarily dangerous or cancerous. But it can cause a lot of pain for sufferers. For example, particular kind of cyst, called a pilonital cyst was discovered because of complaints by soldiers who frequently rode jeeps in World War II. Their complaint of a blister near their tailbones, turned out to be a cyst caused by ingrown hairs in the coccyx. This type of cyst may require surgery if it does not dissipate or drain naturally.
Cystic fibrosis is a condition where many cysts form and burst in the lungs, which causes the lung to fill up with mucus, which results in shortness of breath.