Hard Lump Under Skin: Causes, Symptoms, and Treatment

November 14, 2024

99 16 minutes read

What is a Hard Lump Under Skin?

A hard lump under the skin is a localized area of swelling or growth that feels firm to the touch. These lumps can vary in size from a tiny pea-sized nodule to a larger mass several inches across. They may be visible as a distinct protrusion or only detectable by touch.

Hard lumps can develop in many areas of the body, but are most commonly found in places like:

Under the skin of the face, neck, or scalp
In the armpits
In the groin area
On the arms or legs, especially after an injury
In the breasts

Some lumps sit directly under the top layer of skin, while others may be deeper in the underlying muscle or fat tissue. The depth, along with the size and texture, can provide clues about what might be causing the lump.

It’s important to note that while hard lumps are often harmless, they can occasionally be a sign of a more serious condition that needs medical attention. We’ll discuss the warning signs to watch for later in this article.

Common Causes of Hard Lumps Under the Skin

There are dozens of reasons why hard lumps under the skin might form. Some growths, like skin tags or moles, are extremely common and rarely a cause for concern. Others, like infections or tumors, need to be evaluated and treated by a healthcare professional. Here are some of the most frequent causes:

Infections

Our skin is an important barrier against germs, but sometimes bacteria or other microbes can sneak in through a cut, scrape, or hair follicle and cause an infection. When this happens, the body’s immune system kicks into high gear, sending white blood cells to fight off the invaders. This process causes the hallmark signs of infection: redness, swelling, heat, and pain.

Two types of skin infections that commonly cause hard lumps are:

Abscesses

An abscess is a pocket of pus that forms when the body tries to wall off an infection. They can develop in hair follicles, sweat glands, or puncture wounds that become contaminated with bacteria. Some abscesses are small and resolve on their own, but larger or deeper ones may need to be drained by a doctor.

Symptoms of an abscess include:

A painful, tender lump that’s warm to the touch
Redness and swelling around the lump
Pus or other fluid draining from the center
Fever and chills if the infection spreads

Risk factors for developing an abscess include:

Poor hygiene
Weakened immune system
Diabetes
Exposure to dirty water or equipment (like in hot tubs or tattoo parlors)

Boils

Boils, also called furuncles, are deep skin infections that start in hair follicles. They occur when bacteria, usually staph, get into the follicle and multiply, creating a swollen, painful, pus-filled bump.

Boils tend to be larger and more painful than pimples or superficial abscesses. A cluster of connected boils is called a carbuncle. Boils can occur anywhere on the body, but are most common in areas where hair follicles can become irritated, like the face, neck, armpits, and buttocks.

Symptoms of a boil include:

A red, painful lump that starts small but grows quickly
Tenderness and swelling around the lump
A white or yellow tip that eventually ruptures and drains pus
Fever, chills, and fatigue if the infection spreads

Risk factors for developing boils include:

Close contact with an infected person
Diabetes
Compromised immune system
Skin conditions like eczema or acne
Harsh chemicals or irritants

Most small boils can be treated at home with warm compresses to promote drainage. Larger boils may need to be drained by a doctor. Antibiotics are sometimes needed if the infection is severe or spreads to other parts of the body.

Clogged Glands

Our skin is home to hundreds of tiny glands that produce sweat and oil to keep the skin moist and supple. Sometimes, these glands can become blocked or clogged, leading to hard, painless lumps called cysts.

Epidermal Inclusion Cysts (Sebaceous Cysts)

The most common type of cyst is an epidermal inclusion cyst, sometimes called a sebaceous cyst. These form when a hair follicle or skin pore gets blocked by excess keratin, a protein that makes up skin, hair, and nails.

The plugged follicle continues producing keratin, which builds up into a sac under the skin. These cysts feel like smooth, round, mobile lumps. They’re usually whitish in color and may have a small blackhead-like opening on the surface.

Epidermal inclusion cysts are most often found on the face, neck, chest, and back. They grow slowly and rarely cause problems unless they become very large or get infected.

Symptoms of an epidermal inclusion cyst include:

A small, hard, round lump under the skin
Whitish color
Slow growth over months to years
Usually painless unless infected

Risk factors for developing epidermal inclusion cysts include:

Acne or other skin conditions
Injury to the skin
Sun damage
Genetics (some people are just more prone to them)

Most epidermal inclusion cysts don’t require treatment. If they become inflamed, injected, or are in a cosmetically sensitive area, they can be surgically removed. It’s important to not try to “pop” or drain these cysts at home, as that can lead to scarring and infection.

Benign Tumors

Not all lumps under the skin are caused by infections or clogged glands. Some are benign (non-cancerous) tumors made up of an overgrowth of specific types of cells.

Lipomas

Lipomas are soft, rubbery lumps made up of mature fat cells. They are one of the most common benign tumors, affecting 1 in 1000 people^[2]. Lipomas tend to form in middle age and are more common in men.

These tumors feel soft and movable, like a small pillow under the skin. They usually grow very slowly and don’t cause any pain. Lipomas can occur anywhere there are fat cells, but are most often found on the neck, shoulders, back, and abdomen.

Symptoms of a lipoma include:

A soft, rubbery, movable lump just under the skin
Slow growth over months to years
Usually less than 2 inches across
Painless and non-tender

The exact cause of lipomas is unknown, but risk factors include:

Family history of lipomas
Certain genetic disorders like Gardner syndrome
Obesity
Lack of exercise

Lipomas are harmless and don’t need to be treated unless they are causing discomfort or cosmetic concerns. If needed, they can be surgically removed. Liposuction is sometimes used for very large lipomas. Steroid injections may also help shrink bothersome lipomas.

Dermatofibromas

Dermatofibromas are small, firm bumps that form in the deeper layers of the skin. They are made up of an overgrowth of fibrous tissue and feel like a hard lump or nodule under the skin.

These benign tumors are most commonly found on the legs, but can occur anywhere on the body. They tend to be small (less than 1 cm), round, and reddish-brown in color. When pinched, the top of the lump may dimple inward.

Symptoms of a dermatofibroma include:

A firm, raised bump on the skin
Reddish, pink, brown, or purple color
Dimpling of the surface when pinched
Slow growth over months to years
Usually painless but may be tender when pressed

The exact cause of dermatofibromas is unknown, but they often form at sites of previous injuries like insect bites, cuts, or splinters. They are more common in women and tend to develop in middle age.

Dermatofibromas are harmless and don’t require treatment. If the appearance is bothersome or the lump is constantly irritated by clothing, it can be removed surgically. However, this will leave a scar and the dermatofibroma may grow back.

Neurofibromas

Neurofibromas are soft, fleshy bumps that form along nerves in the skin and deeper tissues. They are made up of an overgrowth of nerve cells and fibrous tissue.

These benign tumors can occur anywhere in the body, but are most often found on the trunk, arms, and legs. They may be skin-colored or slightly pink or purplish. Neurofibromas tend to be small (less than 1/2 inch), but can sometimes grow quite large.

Symptoms of a neurofibroma include:

A soft, fleshy lump on or under the skin
Skin-colored to slightly pink or purplish
Slow growth over years
May be tender or tingly when touched
Rarely painful unless compressed

Neurofibromas most often occur in people with an inherited disorder called neurofibromatosis type 1 (NF1). In NF1, multiple neurofibromas form throughout the body, along with other signs like café-au-lait spots and bone abnormalities. Isolated neurofibromas can also occur in people without NF1, usually as a single lump.

Most neurofibromas don’t require treatment other than regular monitoring. However, if a neurofibroma is growing rapidly, causing pain, or compressing vital structures, it may need to be surgically removed. People with NF1 need ongoing care to watch for complications.

Other Causes

Swollen Lymph Nodes

Lymph nodes are small, bean-shaped glands that filter lymph fluid and store white blood cells. They are part of the body’s immune system and can become swollen in response to infection, inflammation, or cancer.

Swollen lymph nodes feel like firm, tender lumps under the skin. They are usually found in the neck, armpits, or groin, but can occur anywhere in the body. Lymph nodes can swell to several centimeters in size and may be painful when pressed.

Common causes of swollen lymph nodes include:

Viral infections like the common cold, flu, or mononucleosis
Bacterial infections like strep throat or cat scratch disease
Skin infections
Autoimmune disorders like rheumatoid arthritis
Cancers like lymphoma or leukemia

Most swollen lymph nodes are a sign that your body is fighting an infection and will go back to normal once the infection clears. Nodes that persist for more than a few weeks, continue to grow, or are hard and painless should be checked by a doctor, as they could be a sign of something more serious.

Hormonal Changes

Hormonal fluctuations, especially during puberty, pregnancy, and menopause, can sometimes cause benign breast lumps to form. These lumps are usually smooth, round, and mobile, and may be tender to the touch.

Two common types of hormonal breast lumps are:

Fibrocystic changes: These lumpy, rope-like areas of thickened tissue are very common in women of reproductive age. They tend to fluctuate with the menstrual cycle and are usually most noticeable right before a period. Fibrocystic changes are benign and don’t increase breast cancer risk.
Fibroadenomas: These smooth, firm, mobile lumps are made up of both glandular and connective tissue. They are most common in women under 30 and tend to be painless. Fibroadenomas are benign and don’t become cancerous.

Any new breast lump should be evaluated by a doctor to rule out cancer, especially in women over 30. Imaging tests like mammograms or ultrasounds can help determine if a lump is benign or needs a biopsy.

Symptoms of a Hard Lump Under the Skin

The specific symptoms of a hard lump under the skin will depend on the underlying cause. However, some general characteristics to take note of include:

Size: Is the lump pea-sized or larger? Is it growing over time?
Texture: Does the lump feel firm, rubbery, or hard? Is it smooth or irregular?
Mobility: Can you move the lump around under the skin or is it fixed in place?
Tenderness: Is the lump painful or tender to the touch?
Appearance: Is there any change in the color or texture of the skin over the lump? Is there a visible opening or drainage?
Location: Where on the body is the lump located? Is it in an area prone to irritation or injury?

Other symptoms to watch for that could indicate an infection or more serious condition include:

Redness, warmth, or swelling around the lump
Pus or other drainage from the lump
Fever or chills
Night sweats
Unexplained weight loss
Hard, painless lumps that appear suddenly

Noting these characteristics can help your doctor determine the most likely cause of your lump and decide if further testing is needed.

When to See a Doctor

While most lumps under the skin are harmless, it’s important to have any new or changing lump evaluated by a healthcare professional. You should see a doctor for a skin lump if:

The lump is painful, tender, or warm to the touch
The lump is hard, fixed in place, and grows rapidly
There are signs of infection like redness, swelling, drainage, or fever
The lump changes color or texture
The lump interferes with movement or causes numbness/tingling
You have a history of skin cancer or other cancer
The lump persists for more than 2-4 weeks or keeps growing

Your doctor will examine the lump and ask about your symptoms and medical history. They may also recommend tests like a skin biopsy, blood work, or imaging scans to help diagnose the cause of the lump. Catching any potentially serious conditions early offers the best chance for successful treatment.

Diagnosing a Hard Lump Under the Skin

If you see a doctor for a concerning skin lump, they will start by taking a detailed medical history and performing a physical exam. They will ask about:

When you first noticed the lump
If the lump has changed in size or appearance over time
Any pain, tenderness, numbness, or tingling associated with the lump
Your personal and family history of skin conditions or cancers
Any other symptoms you’ve been experiencing

During the physical exam, your doctor will carefully feel the lump to note its size, shape, texture, and mobility. They will also check for any signs of infection or skin changes around the lump.

Depending on their initial assessment, your doctor may recommend one or more of the following tests to help diagnose the cause of your lump:

Skin biopsy: A small sample of tissue is removed from the lump and examined under a microscope. This can help determine if the lump is benign or cancerous.
Fine needle aspiration (FNA): A thin needle is inserted into the lump to withdraw cells or fluid for analysis. This is often used for lumps that may be cysts or tumors.
Imaging tests: X-rays, ultrasounds, CT scans, or MRIs may be used to get a better look at the size, shape, and location of the lump, as well as to check for any spread to nearby tissues.
Blood tests: Lab work may be ordered to check for signs of infection, inflammation, or cancer markers.
Allergy tests: If the lump may be related to an allergic reaction, skin prick tests or patch tests may be done to identify the trigger.

Your doctor will use the results of these tests, along with their clinical judgment, to make a diagnosis and recommend the most appropriate treatment plan. In some cases, a “watch and wait” approach may be recommended for lumps that are likely benign and not causing any symptoms.

Treatment Options for Hard Lumps Under the Skin

Treatment for a hard lump under the skin will depend on the underlying cause and whether the lump is causing any symptoms or cosmetic concerns. Here are some common treatment approaches:

Medical Treatment

Antibiotics

If the lump is caused by a bacterial infection, like an abscess or boil, your doctor may prescribe oral or topical antibiotics to clear the infection. It’s important to take the full course of antibiotics as directed, even if the lump starts to improve, to prevent the infection from coming back.

For very large or deep abscesses, your doctor may need to make a small incision and drain the pus before starting antibiotics. This helps the infection heal more quickly and reduces the risk of complications.

Corticosteroid Injections

For certain types of benign lumps, like cysts or lipomas, your doctor may recommend an injection of a corticosteroid medication directly into the lump. Corticosteroids have anti-inflammatory effects and can help shrink the size of the lump over time.

Steroid injections are usually reserved for lumps that are painful or interfering with movement. They are a good option for people who want to avoid surgery or have medical conditions that make surgery risky.

Surgical Excision

Some lumps, especially those that are large, painful, or potentially cancerous, may need to be surgically removed. This involves making an incision in the skin and carefully cutting out the entire lump, along with a margin of healthy tissue around it.

Surgical excision is typically done under local anesthesia in a doctor’s office or outpatient surgery center. Stitches or staples are used to close the incision, and the lump is sent to a lab for analysis to confirm the diagnosis.

Risks of surgical excision include bleeding, infection, scarring, and numbness or tingling if nerves are damaged during the procedure. Your doctor will discuss the specific risks and benefits of surgery with you beforehand.

Drainage

For lumps that are filled with fluid, like cysts or abscesses, your doctor may recommend a procedure to drain the lump. This involves numbing the area with local anesthesia and then using a needle or small incision to withdraw the fluid.

Drainage can help relieve pain and pressure, but it doesn’t always remove the entire lump. In some cases, the lump may fill up with fluid again over time and need repeated drainage. If a cyst or abscess keeps coming back, surgical excision may be recommended.

Home Remedies

For minor lumps and bumps, some home remedies may help provide relief:

Warm Compresses

Applying a warm, moist compress to the lump for 10-15 minutes at a time, several times a day, can help speed healing and relieve pain. The warmth increases blood flow to the area, which brings more oxygen and nutrients to help fight infection and promote tissue repair.

Warm compresses are especially helpful for lumps caused by infections, like boils or abscesses. The heat can help draw the pus to the surface and encourage the lump to drain on its own.

To make a warm compress:

Fill a clean bowl with warm water. The water should be hot, but not so hot that it burns your skin.
Dip a clean washcloth into the water and wring it out so it’s damp but not dripping.
Apply the warm cloth to the lump and hold it there for 10-15 minutes.
Repeat 3-4 times a day until the lump improves.

Be sure to use a fresh washcloth each time and wash your hands before and after applying the compress to avoid spreading infection.

Prevention

While not all lumps and bumps can be prevented, there are some steps you can take to reduce your risk:

Practice good hygiene: Wash your hands regularly, clean any cuts or scrapes promptly, and avoid sharing personal items like towels or razors to prevent the spread of infection.
Don’t pick or squeeze lumps: Trying to pop or drain a lump yourself can introduce bacteria and make an infection worse. Leave lump treatment to the professionals.
Wear sunscreen: Protecting your skin from UV damage can help reduce the risk of skin cancer and other skin lesions. Use a broad-spectrum sunscreen with an SPF of at least 30 daily.
Eat a healthy diet: A diet rich in fruits, vegetables, and whole grains provides the nutrients your skin needs to stay healthy and fight off infection.
Don’t smoke: Smoking can weaken your immune system and make you more prone to infections and skin problems. If you smoke, quitting is one of the best things you can do for your skin and overall health.
Know your risk factors: If you have a family history of certain skin conditions, like cysts or lipomas, you may be more prone to developing lumps. Be sure to let your doctor know about any skin issues that run in your family.

While you can’t control all the factors that contribute to skin lumps and bumps, making healthy lifestyle choices and being proactive about skincare can go a long way in keeping your skin smooth and bump-free.

Outlook and Prognosis

The outlook for a hard lump under the skin depends on the underlying cause. Most benign lumps, like cysts, lipomas, and dermatofibromas, don’t pose a serious health risk and can be managed with simple observation or removal if they become bothersome.

Lumps caused by infections, like boils or abscesses, usually clear up completely with prompt treatment with antibiotics or drainage. However, some people may be prone to recurrent infections, especially if they have a weakened immune system or other risk factors.

Rarely, a hard lump under the skin may be a sign of a more serious condition, like skin cancer. Skin cancers often appear as new or changing lumps, moles, or patches on the skin. They may be asymmetrical, have irregular borders, vary in color, or grow larger than a pencil eraser.

If caught early, most skin cancers are highly treatable and have a good prognosis. However, advanced skin cancers that have spread to other parts of the body can be more difficult to treat and may require more aggressive therapies.

Your doctor can give you a better idea of what to expect based on your specific diagnosis and overall health. In general, the earlier a concerning lump is evaluated and treated, the better the outcome. That’s why it’s so important to see a doctor if you notice any new or changing lumps on your skin.

Conclusion

Finding a hard lump under the skin can be alarming, but in most cases, these lumps are benign and treatable. From harmless cysts and lipomas to minor infections and hormonal changes, there are many possible causes of skin lumps and bumps.

The key is to pay attention to your skin and note any changes or new growths. While it can be tempting to try to diagnose or treat a lump on your own, it’s always best to see a doctor for an accurate assessment and appropriate care.

With this guide, you now have a better understanding of the common causes, symptoms, and treatment options for hard lumps under the skin. Remember, knowledge is power when it comes to your health. By being proactive and informed, you can take charge of your skin health and feel confident in your care.

Takeaways

Hard lumps under the skin are common and have many possible causes, including cysts, lipomas, infections, and hormonal changes.
Characteristics to note include size, texture, mobility, tenderness, appearance, and location of the lump.
See a doctor for any lump that is painful, hard, fixed, growing rapidly, or accompanied by signs of infection like redness, swelling, or fever.
Diagnosis may involve a physical exam, skin biopsy, imaging tests, or blood work.
Treatment options include antibiotics, corticosteroid injections, surgical excision, drainage, or simple observation depending on the cause.
Most lumps are benign and treatable, but it’s important to have any concerning growths evaluated promptly to rule out skin cancer or other serious conditions.
Practicing good hygiene, protecting your skin from the sun, eating a healthy diet, and avoiding smoking can help reduce your risk of developing skin lumps and bumps.