Lump in the Armpit: Causes, Symptoms, Differences, Diagnosis, Treatment and Overview

They are ubiquitous and are usually caused by a swollen lymph node or gland under the armpit.

However, there are many other causes of armpit lumps, some of which may require treatment.

Fortunately, there are many treatments for lumps that appear under the arm, depending on what caused them. A doctor can diagnose the underlying cause of an armpit lump and prescribe the appropriate treatment.

Causes of a lump in the armpit

There could be several possible causes of armpit bumps. Most armpit lumps are harmless and the direct result of abnormal tissue growth.

However, lumps in the armpits can indicate a more serious underlying health problem. If this is the case, it will most likely require medical intervention.

Some of the more common causes of armpit lumps include:

  • Non-cancerous fibrous tissue growth (fibroadenoma).
  • Cysts or fluid-filled sacs.
  • Allergic reactions to deodorant, antiperspirant, or soap.
  • Viral or bacterial infections.
  • Infections drain into the lump in the armpit.
  • Fatty growths (lipomas).
  • Adverse reactions to vaccines.
  • Fungal infections
  • Breast cancer


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


The texture of the armpit lump can vary 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 can feel stiff and immobile.

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

Infections can cause the following symptoms with the armpit lump:

  • Swelling in the lymph nodes of the body.
  • Night sweats.

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

  • Breast cancer
  • Lymphoma
  • Leukemia.

Differences in men and women

Although both men and women of all ages can have lumps in the armpits, women should pay special attention to nodes in this region, as they can indicate breast cancer.

Women should do monthly breast self-exams and see a doctor for routine exams. If a woman finds a lump, she should report the lump to her doctor immediately.

Generally, a man can wait to see a doctor unless he notices warning signs that the tumor is serious. This is because men are much less likely to find an armpit lump due to breast cancer.

However, although it is rare, men can also develop breast cancer.

When to see a doctor

Any new or recently discovered lump on the body can cause concern. However, not all nodes are harmful or even painful. The severity of a tumor can best be determined through a medical exam and sometimes additional tests.

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

  • Gradual enlargement.
  • Without pain.
  • It does not disappear.

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 to rule out more serious causes. Of course, any unusual lumps must be carefully evaluated.

What happens next

When a person consults a doctor about a lump in the armpit, the doctor usually begins by asking questions about the node. The doctor may ask about any pain or discomfort the person is experiencing.

In addition, the doctor will perform a physical exam. This exam should include hand palpation or massage to determine the consistency and texture of the armpit lump. This procedure allows the doctor to examine the lymph nodes thoroughly.


Only a doctor can determine if an armpit lump is severe or not. A doctor can diagnose the cause with just a simple exam.

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 other causes, such as allergic reactions, infections, and cancer. These tests can include:

  • Allergy test.
  • Complete blood count that measures the number of red and white blood cells.
  • Biopsy (removing a small piece of tissue from the lump for testing).
  • Chest or chest x-ray (mammogram).

Non-harmful lumps may require no further action. Annoying or damaging bumps will undoubtedly involve some treatment.

Treatment for a lump in the armpit

Many people have armpit lumps that do not require any treatment. A doctor can monitor the swelling and ask the person to report any changes they experience.

Your doctor may recommend home remedies for people with armpit lumps that don’t need formal treatment. Many of these can be purchased online, such as:

  • Hot compresses or heat packs.
  • Creams without a prescription.
  • Medicines to relieve pain, such as ibuprofen.

The bumps caused by allergic reactions will disappear when the allergen is removed.

If a bacterial infection causes the tumor, your doctor will likely prescribe antibiotics to clear the infection. The armpit lump should shrink in size and eventually disappear.

Simple procedures may be required to remove fatty lumps or cysts. These procedures are often short and pose minimal risk to the person.

What if the armpit lump is cancerous?

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

If this is the case, a doctor will need to consider treating cancer. Treatment options will be similar to treatment for many other types of cancer. Some possible treatment options include:

  • Surgery.
  • Radiation.
  • Chemotherapy.


The prospect of an armpit lump largely depends on the cause. For instance:

  • A swelling caused by a viral infection will usually go away as the infection clears.
  • The bumps that result from allergic reactions should also disappear once the allergen is removed or reduced.

However, some armpit lumps will not go away without treatment. For instance:

  • A lipoma is not harmful, but it does not go away on its own. As a result, lipomas require medical help to remove.
  • Cancer lumps vary in terms of successful outcomes.

Factors that can affect the prognosis of a person with a cancerous lump under the arm are:

  • The stage of cancer when it was first treated.
  • Whether cancer has spread to other parts of the body.

As with all types of cancer, early detection is essential to help increase the chances of successful remission.

Ultimately, determining the cause of the armpit lump is vital in treatment and prognosis.

When a lump is discovered, it is always good to consult with a doctor to determine the exact cause and decide what needs to be done in terms of treatment.

Outlook for armpit lumps

The outlook for an armpit tumor depends on its cause. For example, a lump that comes from a viral infection will eventually go away. However, while harmless, a lipoma does not go away on its own. A dermatologist can help remove it.