How common are cysts?

A cyst can grow almost anywhere on your body or under your skin. It is a sac-like pocket of membranous tissue containing fluid, air, or other substances.

Cysts are very common, and most are benign -- meaning non-cancerous. You may need tests like a CT scan, ultrasound, or biopsy to confirm that it's a cyst.

Cysts often don't need treatment. Whether one needs treatment depends on a number of factors, including the type of cyst, its location, if it is causing pain or whether it is infected.

In case of a cyst that's causing pain or discomfort, you should see a doctor to make sure that it is nothing serious.

The most common types of cysts are:

ACNE CYST

You get acne when oil and dead skin block a pore. This often causes a small growth that we call pimple. If the pimple is large and squishy, it is likely an acne cyst.

BAKER'S CYST

A soft, fluid-filled lump can form at the back of your knee if you injure the joint because of arthritis, inflammation, torn ligament, or other causes. Resting with leg raised up and applying ice may help. Anti-inflammatory drugs can also help.

BREAST CYST

Breast cysts are pretty common. Lumps with smooth edges around the breasts may hurt before your period starts or when you have lots of caffeine. You don't usually need to treat them, but seeing a doctor about a lump is important because of breast cancer risks.

SEBACEOUS CYST

Another common cyst occurs when something blocks a gland around a hair or irritates the follicle -- often on your face, around the ear or on the head. Usually, it doesn't hurt and smaller ones go away on their own. But your doctor may need to drain or remove larger, swollen, or painful sebaceous cysts.

OVARIAN CYST

Ovarian cysts are fluid-filled sacs or pockets in the ovary or on its surface. Many women may develop this at some time. Most cause little or no discomfort and are harmless. The majority disappear without treatment within a few months. However, some can cause serious symptoms for which you need to see your physician.