An Overview of Axillary Lymphadenopathy (Swollen Lymph Nodes in the Armpit)

Also known as adenopathy

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Axillary lymphadenopathy, also known as adenopathy, describes changes in the size and consistency of lymph nodes in the armpit (axillary lymph nodes). It is not a disease itself but rather a symptom associated with a range of diseases and conditions, from mild infections to breast cancer.

Woman touching her armpit

Pongsak Tawansaeng / EyeEm / Getty Images

This symptom can be worrisome, especially if you're not certain what is causing it. The axillary lymphadenopathy differential diagnosis also may be difficult because of all the possible causes.

This article will discuss possible causes and symptoms to look out for. It will help you to know when to see a healthcare provider and to understand more about diagnostic tests and axillary lymphadenopathy treatment.

Symptoms of Axillary Lymphadenopathy

Axillary lymphadenopathy is characterized by swelling and inflammation of one or more of the 20 to 40 axillary lymph nodes in each armpit. The swelling may involve one armpit, which is known as unilateral, or both armpits, known as bilateral.

Unilateral swelling is often (but not always) a symptom of an infection or disease on that side of the body. Bilateral swelling tends to point to systemic illness—that is, an illness affecting the entire body.

Swollen axillary lymph nodes can range in size from a small pea to a large grape. They can feel spongy or hard like a marble. They may also be accompanied by additional symptoms, including:

  • Warmth of the lymph nodes and surrounding skin
  • Redness of the lymph nodes and surrounding skin
  • Lymph nodes that are painful or tender
  • Lymphedema (swelling of the affected arm)
  • Fever and chills
  • Fatigue
  • Malaise
  • Joint or muscle pain
  • Night sweats
  • Unexplained weight loss
  • Splenomegaly (swollen spleen)

Causes of Swollen Lymph Nodes in the Armpit

Lymph nodes are part of the lymphatic system, which plays a central role in immune function, fluid balance, and absorption of fats and fat-soluble nutrients. Other parts of the lymphatic system include lymph fluid, lymph vessels, the spleen, tonsils, and the thymus gland.

Lymphadenopathy is a sign that the lymphatic system has triggered an immune response to defend against an invader—specifically, an infection or illness. The immune response works like this:

  1. First, the invader enters the lymph vessels and lymph fluid.
  2. Lymph fluid flows to the lymph nodes for inspection by the immune system.
  3. Once the invader is detected, inflammatory proteins (cytokines) and defensive white blood cells (lymphocytes) are released. Their job is to isolate and neutralize the invader within the lymph node.
  4. As a result, inflammation and fluid build-up in the lymph node leads to swelling. We recognize this swelling as lymphadenopathy.

Axillary lymphadenopathy may occur by itself or at the same time as lymphadenopathy of the neck or chest. Generalized lymphadenopathy describes the occurrence of lymphadenopathy throughout the body due to systemic illness.

There are many possible causes of axillary lymphadenopathy, including:

  • Local infection, such as streptococcal and staphylococcal skin infections, or other infections that are localized to the arm, hand, chest, or shoulder
  • Short-term inflammation, such as after receiving a shoulder or arm tattoo
  • Vaccinations for measles, smallpox, tuberculosis, and anthrax, which are linked to unilateral lymphadenopathy on the same side as the injected arm
  • Strep throat, which can affect the axillary lymph nodes as well as the cervical lymph nodes
  • Cat-scratch fever, resulting from a cat scratch on an arm or hand
  • Sporotrichosis, a rare, localized fungal infection that results in swelling of the nearby lymph nodes
  • Hidradenitis suppurativa, a painful skin condition of uncertain cause that affects sweat glands
  • Tularemia, a rare infectious disease that typically attacks the skin, eyes, lymph nodes, and lungs
  • HIV, because axillary and cervical lymph nodes are often affected in the early stages of infection
  • Autoimmune lymphoproliferative syndrome, a syndrome characterized by swollen lymph nodes in the armpit, neck, or groin
  • Lymphoma, a cancer of the lymph nodes and lymphatic tissue that causes swollen lymph nodes, usually in the armpit, neck, or groin
  • Regional cutaneous tuberculosis, a form of tuberculosis characterized by scaly and crusting skin lesions
  • Breast cancer, because axillary lymphadenopathy typically occurs with locally advanced breast cancer or inflammatory breast cancer

Lung, thyroid, stomach, colorectal, pancreatic, ovarian, kidney, and skin cancer can also sometimes metastasize (spread) to the armpit area.


Axillary lymphadenopathy can usually be identified with a physical exam. Your healthcare provider may discover swollen lymph nodes during a routine checkup even if you have no symptoms.

To begin to determine if armpit pain or other symptoms could be related to cancer, infection, or another cause, they will consider several factors, including:

  • Size of the lymph nodes
  • Number of swollen lymph nodes
  • Pain or tenderness
  • Location (unilateral vs. bilateral)
  • Consistency (whether the nodes are hard or spongy)
  • Matting (whether the nodes are conjoined or individual)
  • Mobility (whether the nodes are movable or not)

Together, these clues may point to certain diagnoses and help exclude others.

Diagnostic Clues in Lymphadenopathy Evaluation
Symptoms Suspected Cause(s)
Acute joint pain and stiffness, muscle weakness, rash Autoimmune
Fever, chills, fatigue, malaise Infection
Enlarged spleen, unexplained weight loss of more than 10% Lymphoma, metastatic cancer
Multiple small nodes that feel like "buckshot” Viral infection
A hard, painless or firm, rubbery mass that is fixed Cancer
Swollen lymph nodes appearing days or weeks after exposure HIV

Healthcare providers tend to worry about lymph nodes if they develop for no apparent reason. In such cases, additional tests may be ordered to help narrow down the causes.

Lab Tests and Procedures

In addition to a physical exam, your healthcare provider will review your medical history and symptoms. They'll ask about recent vaccinations, unexplained weight loss, recent sexual exposures, or abnormal skin lesions.

This information will help them determine which tests to include in the workup, such as:

  • C-reactive protein levels: high levels in the blood indicate generalized inflammation
  • Erythrocyte sedimentation rate (ESR): a blood test that reveals inflammation in the body
  • White blood cell count: an elevated lymphocyte count in the blood may suggest infection
  • Infection-specific tests: used to identify HIV, tuberculosis, or streptococcus
  • Immunologic blood tests: used to help detect autoimmune disease
  • Skin biopsy: a procedure that may be done if skin lesions are present
  • Diagnostic mammogram or breast ultrasound: used to detect breast cancer
  • Imaging studies: X-ray, ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI)
  • Lymph node biopsy: used to determine if an infection, autoimmune disorder, or cancer is involved

Differential Diagnosis

Lumps and masses in the armpit don't always indicate lymphadenopathy. Some may be benign or malignant growths not related to the lymphatic system, such as:

  • Lipomas: benign tumors composed of mature fat cells
  • Epidermal inclusion cysts: benign cysts usually found on the skin
  • Fibroadenomas: benign, painless breast lumps that can extend to the armpit
  • Schwannomas: benign tumors of nerve sheaths
  • Malignant neuroendocrine tumors: a cancer involving cells of the nervous and endocrine systems that occasionally affects the armpit

These conditions usually can be differentiated with imaging studies and other procedures, such as fine-needle aspiration.

Axillary Lymphadenopathy Treatment

There is no specific axillary lymphadenopathy treatment. Instead, it is resolved by treating the underlying condition.

Symptoms of lymphadenopathy can respond to certain home or over-the-counter (OTC) remedies:

  • A cold compress may relieve inflammation.
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) like Aleve (naproxen) and Advil (ibuprofen) can relieve pain and inflammation.
  • If an infection is involved, rest is vital.

In cases of advanced breast cancer, the axillary lymph nodes are removed as part of a radical or modified mastectomy.

Lymphadenopathy caused by infection or other inflammatory processes is called lymphadenitis. To prevent the spread of lymphadenopathy to other lymph nodes in your body, your healthcare provider may prescribe antibiotics, antiviral, or anti-fungal medication.


When your body detects a foreign invader—be it an illness, an infection, or even a vaccine—your lymphatic system will trigger an immune response to fend off the perceived threat. As lymphocytes and cytokines attack the invader, your lymph nodes will swell, resulting in lymphadenopathy.

Sometimes, axillary lymphadenopathy can be a sign of a serious illness, such as HIV, lymphoma, or breast cancer. You should make an appointment with your healthcare provider if you are concerned, or if:

  • Your lymph nodes are swollen for no apparent reason
  • The swelling does not resolve within two to four weeks
  • The swelling continues to worsen
  • Your lymph nodes feel hard, irregular in shape, or fixed in place
  • You have a fever, night sweats, or unexplained weight loss

A Word From Verywell

A swollen lymph node is not an uncommon condition. But it should never be ignored if it is persistent, severe, or unexplained. When seeing a healthcare provider, provide as much information as possible about what you had been doing or experiencing before the lymphadenopathy started. The more your healthcare provider knows, the sooner a diagnosis can be made.

Frequently Asked Questions

  • What do lymph nodes in the armpit do?

    Lymph nodes in the armpit fight against infection and cancer. The same is true of your other lymph nodes, which can be found in the abdomen, neck, groin, and pelvis.

  • Can COVID vaccinations cause axillary lymphadenopathy?

    Yes, and it's relatively common. One study found that 44% of people who had breast imaging after a COVID shot had lymphadenopathy up to 43 weeks after vaccination. Talk to your imaging center about the best time to schedule your appointment.

  • Can allergies cause swollen lymph nodes in your armpit?

    Allergies, including medication allergies, may lead to axillary lymphadenopathy. However, this is not a common sign of an allergic reaction.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Indranil Mallick, MD
 Indranil Mallick, MD, DNB, is a radiation oncologist with a special interest in lymphoma.