What causes a hard lump under the skin?
In this article, we cover different types of noncancerous hard lump under the skin, their causes and treatments, and when to see a doctor.
Image credit: Gemalone, 2008.
Image credit: Steven fruitsmaak, 2010.
Image credit: Jmarchn, 2014.
Image credit: Mohammad2018, 2018.
Swollen lymph nodes
Image credit: Hudson Bernard, 2010.
Causes of a hard lump under the skin can include:
A cyst is a closed pocket of tissue that contains fluid or debris. Cysts can form anywhere on the body. Their texture varies depending on the material that has become trapped inside the pocket.
A cyst can develop due to a clogged oil gland or hair follicle. Cysts feel like soft blisters when they are close to the skin's surface, but they can feel like hard lumps when they develop deeper beneath the skin.
A hard cyst near to the surface of the skin usually contains trapped dead skin cells or proteins. Types of cyst include:
- ganglion cysts, which are common on the wrists and hands
- synovial cysts, which develop on the spine
- pilar cysts, which appear on the scalp
- mucous cysts, which can form on the feet, toes, or inside of the mouth
Cysts rarely require treatment, and they will often stop growing and then disappear on their own. In some cases, a blackhead can develop near the center of a cyst. When this happens, a cyst may burst open, releasing white or yellow discharge.
An infected cyst that is red, swollen, or painful may require medical treatment, such as:
- needle aspiration
- corticosteroid injections
- a surgical procedure to remove the cyst
In general, people who have dermatofibromas do not experience other symptoms. However, in some cases, the dermatofibroma may feel itchy, irritated, or tender to the touch.
Dermatofibromas develop when excess cells collect in the thickest layer of the skin, which is called the dermis.
The exact cause of dermatofibromas remains unclear, but potential causes include:
- trauma or injury to the skin
- insect or spider bites
Dermatofibromas do not generally require treatment, but they tend to stay on the skin for the rest of the person's life.
People can ask a doctor to remove a dermatofibroma surgically if it is unsightly or in a bothersome area.
The other treatment options will only remove part of the dermatofibroma. They include:
- freezing it with liquid nitrogen
- corticosteroid injections
- shaving off the top layers of the growth
- removing its center
Swollen lymph node
A cold or viral infection can cause swollen lymph nodes.
Lymph nodes are small glands that filter harmful substances from lymph fluid, which is the clear liquid that travels through lymphatic vessels.
These small, bean-shaped glands are an essential component of the immune system. They produce and store white blood cells that destroy disease-causing pathogens and waste.
Sometimes, lymph nodes swell in response to bacterial or viral infections. They may feel hard and painful.
Swollen lymph nodes usually occur in the head, neck, armpits, or groin.
Several factors can cause swollen lymph nodes, such as:
- a cold or another viral infection
- bacterial infections
- tooth infections
- ear infections
- medical conditions that affect the immune system, such as rheumatoid arthritis or lupus
People who have swollen lymph nodes due to infection are likely to experience other symptoms, such as:
In most cases, swollen lymph nodes will heal on their own without medical treatment. If they do not, the focus of treatment should be to address the underlying cause, which is usually an infection.
A swollen lymph node that feels hard, rubbery, or immovable may indicate a more serious medical condition.
In general, lipomas do not cause symptoms. However, a lipoma that involves multiple blood vessels or nerves may feel tender or painful.
The exact cause of lipomas remains unknown. Some genetic conditions, such as Gardner's syndrome, can increase a person's likelihood of developing a lipoma.
Lipomas do not require medical treatment unless they are painful, bothersome, or interfering with a person's ability to function normally.
Treatment options for lipomas include:
- steroid injections
- surgical excision
A fibroadenoma is a benign breast tumor that consists of fibrous tissues and gland tissues.
According to the American Cancer Society, fibroadenomas most commonly occur in women in their 20s and 30s, though they can happen at any age. Fibroadenomas usually feel firm but movable.
Fibroadenomas that are not painful or growing will not require medical treatment. However, people should monitor themselves for any changes in the size or appearance of a fibroadenoma.
A doctor may recommend removing a fibroadenoma if:
- it causes pain
- the person experiences changes in the shape or appearance of their breast
- the person has a family history of breast cancer
When to see a doctor
A person with a hard lump under their skin should see a doctor.
In general, a noncancerous lump will feel soft and moveable. Anyone concerned about a hard lump under their skin should see a doctor for a diagnosis. Hard lumps are often nothing more than a cyst or swollen lymph node.
People should seek medical attention for a lump under the skin if:
- they notice any changes in the size or appearance of the lump
- the lump feels painful or tender
- the lump appears red or inflamed
- they also experience unintentional weight loss
A doctor can help diagnose a lump under the skin by examining it and reviewing the person's medical history. During the physical examination, they might gently squeeze or pinch the lump.
The doctor will also ask how long the lump has been present and whether or not it has changed in size or appearance.
A lump that appears irritated or abnormally shaped might require further testing. Tests may include:
- Imaging tests. Doctors may use MRIs, CT scans, X-rays, and ultrasounds.
- A blood test. A doctor might order a blood test to evaluate a person's white blood cell count or check for hormonal imbalances.
- A needle biopsy. During a biopsy, a healthcare professional removes a small sample of tissue from inside the lump for further evaluation.
A hard lump under the skin does not necessarily indicate cancer. Infections, clogged glands, and hormonal changes can all cause noncancerous lumps under the skin.
People should not try to remove or pop a lump. Doing this may lead to an infection or cause the lump to get bigger.
People should speak with a doctor if they have any concerns about a new or altered lump under their skin.
Most lumps will not require medical treatment as long as they do not grow larger or cause pain. People can discuss treatment options with a doctor if their lump causes any discomfort.