Finding a lump or swollen lymph node in your underarms could be linked to a common condition called axillary lymphadenopathy.

Also called axillary adenopathy or armpit lump, axillary lymphadenopathy occurs when your underarm (axilla) lymph nodes grow larger in size. While this condition may be concerning, it’s usually attributed to a benign cause. It may also be temporary.

In some cases, however, an enlarged axillary lymph node may be related to something more serious, such as an infectious disease or cancer.

It’s important to be aware of any changes to your underarm lymph nodes, as well as any symptoms of illness that occur at the same time. While many cases of axillary lymphadenopathy may resolve on their own, others require further medical attention.

Here’s what you need to know about the symptoms, causes, and treatment options.

Lymphadenopathy refers to a swelling of your lymph nodes. When you have axillary lymphadenopathy, this means the condition is affecting the lymph nodes in the underarm area.

With axillary lymphadenopathy, you may notice the following symptoms:

  • a visible armpit lump
  • lymph nodes that are growing larger in size, or more than 2 centimeters (larger than 3/4 inch)
  • bumps around the armpit area that are changing shape
  • pain or tingling sensations
  • fever or chills (in cases of infection)

Axillary lymphadenopathy is sometimes a side effect of certain vaccines and was previously a common symptom seen after smallpox vaccinations. Now, with the recent COVID-19 vaccines on the market, some people are reporting axillary lymphadenopathy as a side effect.

Swollen axilla lymph nodes are most commonly seen in two-dose mRNA COVID-19 vaccines. However, like other side effects, these are considered temporary in most people.

If you have any upcoming imaging tests, tell your doctor about your recent COVID-19 vaccine in case axillary lymphadenopathy presents itself in your results. You should also see your doctor if you’re concerned about any changes in your underarm lymph nodes following any vaccine.

Axillary lymphadenopathy may be attributed to numerous causes. It may be temporary, such as in the case of an infection, or long term depending on whether it’s caused by cancer or a chronic medical condition.

Infections or medical conditions that may cause lymph node swelling in the axillary include:

Sometimes an armpit lump may be caused by a:

As you age, there’s a greater risk that axillary lymphadenopathy could have a malignant cause. Cancers that may cause this condition include:

Diagnosis for axillary lymphadenopathy involves a combination of physical exams, blood work, and imaging tests. The latter may include a:

In some cases, a biopsy may be recommended. During this procedure, a small sample of cells are collected through a fine needle and then sent to a pathologist to determine whether these are benign or malignant.

Your doctor will also see whether your condition is unilateral or bilateral.

  • Unilateral. Unilateral axillary lymphadenopathy means that it occurs on one side of the body only and is sometimes associated with breast cancer. However, unilateral cases can also be caused by autoimmune diseases, and not necessarily breast cancer.
  • Bilateral. Bilateral cases occur on both sides of the body. These may be caused by other types of cancers and medical conditions.

Treating axillary lymphadenopathy depends on the underlying cause. Benign cases that don’t cause any other symptoms may be treated with a watchful approach only.

However, if your condition is caused by an infection, or an autoimmune or inflammatory disease, your doctor may prescribe steroid treatment. This may help to reduce the size of lymph nodes as well as pain and tenderness.

Malignant causes of axillary lymphadenopathy aren’t as common. However, prompt diagnosis and treatment is crucial in preventing the further spread of cancer to other lymph nodes, as well as vital organs.

If your condition is deemed cancerous, your doctor will refer you to an oncologist. This cancer specialist will stage the cancer and then determine the most appropriate treatment for your condition, such as:

Axillary lymphadenopathy affects the lymph nodes in your underarm area. It has numerous causes, most of which are benign.

While axillary lymphadenopathy isn’t uncommon, an accurate diagnosis is important. Your doctor can rule out underlying cancers or other serious conditions that may be causing lymph nodes in your axilla to enlarge.

See your doctor right away if you notice any changes in your underarm lymph nodes including pain, large size, tenderness, and more.