Cysts are abnormal growths filled with air, liquid, or other material and can develop under the skin or in the bone. They come in many varieties, distinguished by their color, location on the body, cause and symptoms. While there are hundreds of different types of cysts, the most common include skin cysts such as sebaceous cysts and cherry angiomas, ovarian cysts, chalazions, and ganglion cysts.

Skin cysts are the most common and thankfully, one of the most innocuous types of cysts. They do not cause cancer and can form anywhere either on the skin or beneath its surface. These cysts can be drained, though they sometimes go away without any treatment.

Cherry angiomas form on top of the skin and are, predictably, red and smooth. This type of cyst is more common in the over 40 crowd. While they are harmless, they may be removed for aesthetic reasons.

Sebaceous cysts develop under the skin and contain a cheesy or oily substance. Hair follicles are a prime spot for these inflammations. As with many types of cysts, those inflicted with sebaceous cysts should refrain from scratching or picking at the affected area, as infection may occur. Wet, warm compresses can be used to relieve any swelling or pain; if the cyst does not go away or worsens, seek medical treatment. Removal may be necessary.

Ovarian cysts can form painlessly and disappear on their own, but they can be painful if they grow large or affect the ovary itself. Ovarian cysts can be caused by an egg sac that doesn’t properly break open or dissolve as part of the menstrual cycle. Endometriosis, a condition where the tissue found inside the uterus appears elsewhere in the body, can also be a cause of ovarian cysts called endometriomas.

Chalazions appear around the eyes or eyelids and may resemble pimples. This type of cyst is caused by clogged and inflamed glands. Infection can worsen these bumps, so touching them unnecessarily is not recommended. Most chalazions can be eased at home with the application of warm compresses and doctor-prescribed drops or creams.

Ganglion cysts develop in the tissues near joints and tendons, often in the wrists, ankles and behind the knees (known as a Baker's cyst). This type of cyst is usually filled with a thicker fluid than skin cysts. Ganglion cysts cause painful swelling. No one is quite sure what causes ganglion cysts, but many will vanish without any treatment. If a ganglion becomes too painful to bear or interferes with daily activities like driving or walking, it can be drained and treated with steroid injections.

Cysts can also be characterized based on whether or not they are cancerous. Benign cysts are noncancerous cysts. Malignant cysts are cancerous, and precancerous cysts are not cancerous but have the potential to become cancerous. If you are concerned about these types of cysts or any other lumps and bumps, you should leave the area alone and see a health care professional.