Anytime you get a new lump under your skin, it’s important to figure out what’s going on. It can be confusing if you start looking online to understand your symptoms. You may wonder, “Is this an abscess, a cyst, or something else?”

The best way to get a clear answer is to see a professional. A healthcare provider can examine the lump and recommend the right next step.

What Is the Difference Between an Abscess and a Cyst?

An abscess is a pocket of pus that often forms when the body reacts to an infection. A cyst is an abnormal pocket that may hold fluid, semisolid material, or solid material.

Hidradenitis suppurativa (HS), a skin condition that can cause painful lumps deep in the skin, can also cause deep, abscess-like lumps that may resemble cysts.

Below are six key differences between abscesses and cysts.

An abscess is a buildup of pus anywhere in your body. When your immune system is fighting something, such as a bacterial infection, white blood cells move to that area.

This can cause inflammation. As a result, a pocket can form where white blood cells, bacteria, fluid, and dead tissue collect.

A cyst, on the other hand, is a pocket that may contain fluid or other material, like proteins or dead skin cells.

An abscess is often caused by infection. A bacterium called Staphylococcus is usually the culprit. Your body’s response to this bacterium causes a flood of white blood cells to the area, which can lead to inflammation and pus.

Cysts can have many causes. Some form when ducts become blocked, after an injury, or because of changes in cells.

HS isn’t the same as an ordinary bacterial abscess or a typical cyst. Instead, HS can cause painful lumps in skin folds that may look like pimples, acne cysts, boils, or sores.

If you have recurring lumps in the armpits, groin, thighs, buttocks, or under the breasts, a dermatologist can help determine if HS is the cause.

Sometimes, a cyst becomes infected or inflamed and starts to look more like an abscess. This is one reason diagnosis can be confusing.

A cyst that ruptures or becomes infected can be painful, swollen, and red or discolored.

To treat an abscess caused by infection, a healthcare provider may need to remove the pus so the area can heal. A doctor may perform a procedure called incision and drainage, or I&D.

Your provider may also prescribe antibiotics, depending on the specifics of your case.

Incision and drainage is not usually recommended for HS lesions. It may temporarily relieve pressure from a painful HS abscess, but HS lesions usually come back afterward.

Cysts that cause no problems often don’t need treatment. Treatment may be recommended if a skin cyst is infected, painful, large, or disruptive to your life.

The best option is to have a doctor look at your cyst and help you decide what to do. They may decide to remove your cyst surgically.

A very small skin abscess may go away on its own, and warm compresses may help it drain naturally. However, you shouldn’t try to drain, squeeze, or burst an abscess at home because this can spread bacteria to other areas of the body.

See a healthcare provider right away if you have fever, redness or skin discoloration, swelling, or increasing pain with a suspected abscess. These may be signs of an infection that needs medical care.

A cyst without pain, redness, or other skin discoloration is usually less urgent. Still, a new or unexplained lump should be checked by a healthcare provider.

Not all abscesses are painful, but pain is one of the common symptoms of a skin abscess. A skin abscess may also feel tender and hot.

Cysts may or may not hurt. Many skin cysts don’t cause problems or need treatment, but they can become sore, inflamed, or infected.

HS lesions can be extremely painful. If you’re noticing recurring painful lesions that burst and leak pus, ask your doctor about HS.

Talk to a Doctor

The best thing you can do for any new lump or bump under your skin is to talk to a doctor. Seek care right away if the lump is painful, tender, swollen, red or otherwise discolored, warm, draining pus, or accompanied by fever or chills. These may be signs of an abscess or another infection.

If you have recurring abscess-like lumps in places where skin rubs together, such as the armpits, groin, inner thighs, buttocks, or under the breasts, ask about hidradenitis suppurativa.