Read on to find out more about the different kinds of lumps, what causes them, and when to contact a doctor.

There are many different types of lumps that can form under your skin.
Abscess
An abscess is a round, pus-filled lump that develops when bacteria enter your skin through a cut or wound. Your body reacts to the bacteria by sending white blood cells to the infection site. These white blood cells, bacteria, and dead skin form an abscess that is filled with pus.
Cyst
A cyst is a small, round lump under your skin. Cysts usually develop when dead skin cells move into your skin instead of shedding. Cysts can also form when hair follicles become irritated or damaged.
Ganglion cyst
A ganglion cyst is a small, round lump filled with fluid that often develops under the skin on your hands. If you apply pressure to the cyst, you can move it slightly. Ganglion cysts may form when your joints and tendons become irritated.
Lipoma
Lipomas are common, usually harmless growths of fatty tissue that grow under your skin. Most lipomas range between
Lipomas are more common in males than in females.
Dermatofibroma
Dermatofibromas are small, hard bumps that are usually harmless. Dermatofibromas develop when excess cells collect in the dermis, the thickest layer of the skin. They are often found on the lower leg.
Although they are harmless, dermatofibromas may itch or hurt at times. They sometimes develop in the spot where there was a splinter, insect bite, or minor wound.
Lymph gland swellings
Your lymph glands are pea-sized groups of cells located in various parts of the body. Lymph glands trap and destroy bacteria and viruses. Bacterial or viral infections and some immune disorders can cause your lymph glands to swell.
You can find lumps under your skin anywhere on your body. See below for some of the more common places where you might find a lump.
Lump in the armpit
A lump that you find in your armpit is most likely a swollen gland or lymph node. Swollen glands often occur due to mild infections like colds, sore throats, and tonsillitis. These types of lumps are usually soft and sometimes painful.
Other causes of a lump under your armpit include:
- noncancerous cysts
- harmless fatty growths called lipomas
- allergic reactions to deodorant, antiperspirant, or soap
Glands under the armpit can sometimes swell if you have rheumatoid arthritis. Less commonly, these lumps can be a sign of cancer.
Learn more about armpit lumps.
Lump in the throat
Feeling a lump, bump, or swelling in your throat without having an actual lump is known as globus sensation. Stress, grief, anxiety, and pride are intense emotions that may trigger globus sensation.
A lump in the throat that persists and slowly gets bigger may be a sign of throat cancer.
Lump behind the ear
Lumps or nodules behind the ears are usually harmless. They can vary in size and be painful or painless. They are usually a sign of infection caused by an ear or throat infection, cyst, abscess, or even acne.
Sometimes, an ear infection that is not treated can develop into a more serious ear infection known as mastoiditis. Mastoiditis develops in the bony protrusion behind your ear, which is called the mastoid. The pus-filled cysts that develop can feel like lumps.
Lump in the breast
Up to 80% of breast lumps are benign. Some females have breast tissue that naturally feels lumpy, which is a condition called fibrocystic breasts. Some causes of lumps in your breast are cysts, benign tumors, lipoma, infections, and cancer.
Read about what to do if you find a breast lump.
Lump on the back of the neck
A lump on the back of your neck can often be a swollen lymph node, especially if you have an ear or throat infection. It can also be a cyst, boil, or acne. An allergic reaction to some hair products can also cause lumps.
If the lump on the back of your neck is immovable, firm, and painless, this can be a sign of cancer.
Lump on the testicle
Lumps or swellings on your testicles or scrotal skin are usually benign. Some causes are cysts, inflammation of the tube that stores sperm, hernias, or swollen veins. In rare cases, lumps may be a sign of testicular cancer.
Learn more about testicle lumps.
Lumps can form under your skin for many reasons. They can occur due to infection, inflammatory diseases, trauma, and tumors.
Infections
If you have a local infection, you may notice a lump or abscess. Lumps that occur due to infection usually disappear when the infection clears up.
Inflammatory diseases
Conditions that produce inflammation throughout your body may cause lumps. Rheumatoid arthritis may cause firm lumps under the skin near the affected joints.
Tumors
A tumor is typically a solid mass of tissue. It can be benign and harmless, or it may be malignant or cancerous.
Contact your doctor if you have, or suspect you have, a tumor.
Treatment for lumps depends on which type of lump you have, where it is on your body, and how long you have had it.
Abscess
If you have a lump that occurs as a result of an infection, it will usually disappear when the infection clears up. Your doctor may recommend antibiotics to help clear the infection.
Cyst
Putting a hot compress on a cyst can speed up the healing process by helping it drain. In some cases, it may be necessary to surgically remove a cyst.
Lipoma
You do not have to treat most lipomas. If you do not like the way it looks or it becomes painful or very large, you can have the lipoma surgically removed. Liposuction is another treatment option, although
Tumor
If your tumor is benign, you most likely will not need to treat it. Your doctor may suggest waiting to see whether the tumor grows or becomes painful.
Numerous treatment options are available for cancerous tumors. These
- chemotherapy
- radiation
- immunotherapy
- stem cell or bone marrow transplants
- hormone therapy
Your doctor will begin by performing a physical exam. They may recommend waiting to see whether the lump goes away or changes.
In
If the biopsy shows that the lump is not benign, your doctor may order a CT scan or MRI scan.
Many lumps under the skin will disappear without treatment. Soft, movable lumps are usually harmless and will most likely disappear over time.
Lumps have a wide range of causes, and it is not always possible to tell exactly what caused a lump. Contact your doctor if you are concerned about a lump or if you notice any of the following symptoms:
- redness of the skin around the lump
- pus or fluid that leaks from the lump
- swelling or pain in the surrounding area
- changes in color, shape, or size
- steady growth of the lump
- hard or painless lumps that appear suddenly
- fever, which could be a sign of infection
What does a lump feel like?
Lumps can feel hard or soft. They can be painful or painless. Some lumps move easily when you touch them.
What causes a hard lump?
Cysts, lipomas, swollen lymph nodes, and dermatofibroma are common hard lumps. Cysts can feel like blisters when near the surface of the skin, but they can also feel like hard lumps when they develop deeper beneath the skin.
Does a lump mean cancer?
Most lumps are not cancerous. For example, 80% of breast lumps are benign. Bumps that are cancerous are typically large, hard, and painless. They usually appear spontaneously and grow steadily.
Where are breast lumps usually found?
Breast lumps are usually found in the upper outer portion of your breast.
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- Lumps in and Around the Ear: Medical Causes
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- Medical Causes of a Lump in Your Leg and Related Symptoms
While finding a lump can cause some people to worry, it is helpful to know that most lumps are benign. Many will disappear without medical intervention.
A lump can be hard, soft, large, or small. Examples of types of lumps include cysts, lipomas, and abscesses. Many lumps occur due to inflammatory diseases and infections.
Contact your doctor if you have a lump that does not go away on its own. They will be able to test for any underlying medical causes or conditions.