Painful armpit lumps are often due to a swollen axillary lymph node under the armpit. This is usually a sign that the body is fighting an infection, but it can sometimes indicate cancer. Cysts and fatty growth can also form lumps under the arm.

Axillary is the medical term for the armpit area.

This article explores causes, symptoms, diagnosis, and treatment for armpit lumps.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Learn more.

A persons hand stroking their armpit 1Share on Pinterest
Fiordaliso/Getty Images

There could be a number of potential causes of armpit lumps. In some cases, armpit lumps are harmless and will resolve on their own.

However, armpit lumps may indicateTrusted Source a more severe underlying health issue. If this is the case, it will most likely require medical intervention.

Some possible causes of armpit lumps include:

The most obvious symptom of an armpit lump is the lump itself. The lumps can range in size from very tiny to quite large.

The texture of the armpit lump may varyTrusted Source according to what is causing it. For example, a cyst, infection or fatty growth may feel soft to the touch. However, fibroadenomas and cancerous tumors may feel hard and immobile.

Some people may experience pain with an armpit lump. Painful lumps are often associated with infections and allergic reactions, which cause softer lumps. Lymph node infections may also cause painful lumps in the armpit.

An infection may cause the following symptoms to occur with the armpit lump:

Lumps that change in size gradually or that do not go away may be symptoms of more severe conditions such as:

  • breast cancer
  • lymphoma
  • leukemia

Differences in males and females

Armpit lumps occur in males and females of all ages. These lumps are often temporary and not the sign of a severe condition. However, females should be particularly aware of armpit lumps as they may indicate breast cancer.

The United Kingdom’s National Health Service (NHS) recommends that females perform monthly breast self-exams and see a doctor for routine exams. If they find a lump, they should report the lump to their doctor right away.

Males can generally wait to see a doctor unless they notice warning signs indicating the lump has a severe cause. This is because they are far less likely to find a lump in the armpit that is due to breast cancer. However, while rareTrusted Source, males can also develop breast cancer.

When a person sees a doctor about an armpit lump, the doctor will generally start by asking them questions about the lump. They may ask about any pain or discomfort the person is experiencing.

In addition, the healthcare professional may performTrusted Source a physical examination. This examination may include a hand palpation or massage to determine the consistency and texture of the armpit lump. This procedure allows the doctor to thoroughly examine the lymph nodes.

In other cases, a doctor may request that the person monitor the lump closely to check for any changes over time.

Sometimes, a doctor will order additional tests to help rule out certain causes. These tests might include:

Treatment for armpit lumps will depend onTrusted Source the underlying cause.

Some armpit lumps will not require any treatment. A doctor may simply monitor the lump and ask the person to report any changes they experience.

For people with armpit lumps that do not need formal treatment, the doctor may recommend home remedies, such as:

Lumps caused by allergic reactions will clear up when the allergen is removed. If the lump is caused by a bacterial infection, the doctor may prescribe antibiotics to clear the infection. The armpit lump should reduce in size and eventually disappear.

Healthcare professionals may recommendTrusted Source medical procedures to remove lipomas or cysts, such as surgery or liposuction.

What if the armpit lump is cancerous?

Unfortunately, some lumps have more severe causes, such as cancerous tumors.

If this is the case, treatment options will be similar for many types of cancer. Some possible treatment options include:

The outlook for an armpit lump depends largelyTrusted Source on the cause.

For example, a lump resulting a viral infection will usually go away as the infection clears up. Similarly, lumps that result from allergic reactions should also clear up once the allergen is removed or reduced.

However, some armpit lumps will not disappear without treatment. For example, a lipoma is not harmful, but will notTrusted Source go away on its own. Lipomas require medical help to remove.

Cancerous lumps vary in terms of individual outlooks. Factors that may affect the outlookTrusted Source for someone with a cancerous lump under their arm include the stage of the cancer at initial treatment, whether the cancer has spread to other parts of the body, and their overall health.

Noticing a lump on the body could cause concern. However, not all lumps are harmful or even painful. The severity of a lump can be best determined through medical examination and sometimes additional testing.

Warning signs that may indicate a more severe armpit lump include:

  • gradual enlargement
  • no pain
  • does not go away

If a person experiences or notices any of these symptoms, or has any concerns about the lump, they should see their doctor as soon as possible.

Armpit lumps may have a range of underlying causes, such as infections, allergic reactions, and lipomas. Sometimes, they may be a sign of cancer.

If a person notices an armpit lump, it is always a good idea to consult with a doctor to determine the exact cause and any appropriate treatment.