Lumps can form under the skin for many reasons, including cysts or swollen lymph nodes. Often they don’t require treatment, but if they change in size or appearance, contact a doctor for an exam.


Lumps, bumps, or growths under your skin aren’t uncommon. A lump can form under your skin for many reasons.

Read on to learn more about common causes of hard lumps under your skin and when it’s a good idea to have a lump checked out.

Often, lumps are harmless (benign). Specific traits of the lump can sometimes tell you more about possible causes and whether you should contact a medical professional.

Harmless bumps don’t need to be treated unless you wish to remove them for cosmetic reasons or they become infected. These include:

Cause of lumps that may require treatment include:

  • Keratoacanthoma (KA): This skin tumor is more common in areas with high sun exposure, such as the hands or face.
  • Skin abscess:This is a round, pus-filled lump most commonly caused by bacterial infections. Treatment often involves drainage and antibiotics.
  • Swollen lymph nodes: Lymph nodes respond to infections by trapping and eliminating damaged or infectious cells. Lymphocytes can cause swelling in the nodes as part of the immune response. This can also be caused by injury and, in some cases, cancer. The treatment depends on the cause.
  • Hernia: This is a lump that develops when part of your body, such as one of your organs, pushes through the surrounding tissue. There are several types of hernias.

Doctors can usually diagnose benign skin tumors by looking at their location, appearance, and additional features, such as whether it hurts, itches, or bleeds.

If there is any doubt or the tumor starts to change unexpectedly, you may need to have it removed and analyzed with a biopsy.

Your doctor may also order imaging, such as an MRI, CT scan, or ultrasound.

Often, hard lumps don’t require medical treatment. But it’s always a good idea to talk with a healthcare professional like a dermatologist if you experience growths on your skin that change shape, color, or size.

Typically, a non-cancerous lump will have a soft texture and be able to move under the skin. So if you notice a hard lump, see a doctor for a proper diagnosis. That said, cancerous lumps may also be soft.

Also see a doctor if the lump:

  • bleeds or leaks
  • causes pain
  • grows larger
  • becomes red or inflamed
  • is accompanied by unintentional weight loss

Lumps under the skin are very common and can have a range of causes. In some cases, lumps go away without treatment.

It’s not always possible to tell exactly what causes a lump. If you notice a lump under your skin, keep an eye on it. In general soft, movable lumps are harmless and may improve with time.

That said, it’s always a good idea to make an appointment with a healthcare professional, especially if you’re worried.