What are the Causes of Armpit Pain? (2023)

Armpit pain has many causes. These can range from those that are mostly a nuisance to serious conditions. Pain may be the only symptom, but it is possible to also have a rash or swollen lymph nodes in or around the armpit.

This article will look at what makes up the armpit (axilla), the many possible causes of armpit pain, how it's diagnosed, and your options for treatment and prevention.

Causes of Armpit Pain

The armpit is made up of structures like nerves, skin, sweat glands, blood vessels, lymph nodes, muscles, or bones. Armpit pain can be caused by various things that can affect these individual parts. Conditions involving structures outside the armpit can cause referred pain—pain that comes from a different area than where it's felt.

Some things may cause pain in only one armpit. Others can make both sides hurt.

Here are some of the things that can cause armpit pain:

Muscle Strain

Any of the muscles in and around the axilla can become painful from overuse and muscle strain. Activities that can cause this type of pain include:

• Lifting
• Pulling
• Throwing
• Pushing

Pressure on the muscles and other armpit structures (e.g., from using crutches) can also cause pain.

Injuries

Armpit pain is often the result of an injury. Structures in the armpit can be injured in several ways.

A vulnerable spot is the network of nerves forming the brachial plexus. It can be injured when an arm is forcefully pulled or flexed. Armpit pain may be caused by:

• Loss of motion in the shoulder
• Weakness
• Numbness or tingling in the hand or arm

Other injuries in this region, including shoulder dislocations, can cause axilla pain.

Skin Irritation

Irritated skin in the armpit can lead to pain. This can be caused by:

• Clothing that's tight under the arms
• Rough fabrics
• Shaving

Personal care products can cause either irritant contact dermatitis or allergic contact dermatitis. Those are both skin reactions to things that touch the skin. One is simple irritation while the other is an allergic reaction.

Products that can cause irritation include:

• Deodorants
• Soaps and body washes
• Lotions
• Shaving cream
• Laundry detergents or fabric softeners

Rashes

The armpit is a prime rash site because of the skin folds and a tendency to be warm and wet. Rashes that can affect the armpit include:

• Acanthosis nigricans: A velvety rash with darkened skin. It's often found in skin folds and is more common in people with diabetes or obesity.
• Psoriasis: A scaly rash caused by a build-up of dead skin cells. The skin is red or dark with silvery scales.
• Hidradenitis suppurativa: A chronic condition involving sweat glands. The rash is similar to severe acne.
  

Infections

The armpit's skin folds and warmth make it a good breeding ground for infection. Many of these are fungal or bacterial. Both local and systemic (bodywide) infections can lead to armpit pain. Some of these cause inflammation in the axilla. Others affect the lymph nodes in the armpit.

Fungal Infections

Fungal infections common to the armpit include:

• Intertrigo: A type of yeast infection (candidiasis). Usually causes a very red, shiny rash with scaling in areas where skin touches skin.
• Ringworm (tinea corporis): May occur anywhere on the body. Often causes an itchy rash in circles that get bigger as it grows.

Bacterial Infections

Several common bacterial skin infections may lead to pain in the armpit. They're often associated with redness or swelling.

Erythrasma is a common one. It begins as a pink rash that turns brown and scaly. It's often mistaken for a fungal infection. However, erythrasma is caused by the Corynebacterium minutissimum bacteria.

Other infections include:

• Cellulitis: A deep infection causing red, swollen skin. It may cause fever and red streaks moving away from the site. Can be a medical emergency.
• Folliculitis: Infection in the hair follicles. Red spots develop, possibly with a red ring around them.
• Furuncles (boils): A red bump filled with pus. May quickly get bigger.
• Carbuncles: A cluster of boils. May also cause fever and fatigue.
  

Untreated boils may develop into an abscess.

Generalized Infections

Some generalized infections can cause painful, enlarged lymph nodes in the armpit.

Enlarged Axillary Lymph Nodes

Pain in the armpit may be accompanied by swollen, tender lymph nodes (lymphadenitis). The swelling may not be obvious early on. It may affect one or both sides.

Axillary (armpit) lymph nodes may swell for a number of reasons. Common reasons include infections, autoimmune disease, and cancer.

Systemic Infections

Body-wide viral infections can cause pain and swelling in the lymph nodes. These can be:

• Viral: Mononucleosis (mono) and HIV/AIDS
• Bacterial: Cat scratch disease, syphilis, tuberculosis
• Parasitic: Toxoplasmosis

Infections in nearby body parts may also drain to the lymph nodes in the axilla. That can cause pain and swelling. These other areas may be the:

• Breast (mastitis)
• Hand
• Arm
• Neck
• Parts of the chest and upper abdomen

Autoimmune Disease

In autoimmune diseases, your immune system mistakes a healthy cell or tissue for something harmful, like a virus. It then launches an attack.

Autoimmune disorders like rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE or lupus) sometimes lead to enlarged, painful lymph nodes in the armpit.

Cancer

Some cancers begin in the axillary lymph nodes. Others may spread to them.

Lymphomas, such as Hodgkin's lymphoma, may begin in these lymph nodes.

Many cancers can spread to the axillary lymph nodes. Some common ones include:

• Breast cancer
• Lung cancer
• Melanoma (a type of skin cancer)

In some cases, lymph node pain and swelling may be the first sign of cancer.

Nerve Compression

Nerve compression (pinched nerves) in the armpit may cause armpit pain. It's often a burning pain. You may also have weakness, tingling, or numbness in the hand or arm.

Nerve compression may be caused by:

• An injury
• Pressure on the nerves from a tumor or swelling
• Pancoast tumors (from a type of lung cancer). Pancoast tumors also cause swelling of the face, neck, or upper arms.

Heart Disease

Chest pain isn't always the primary symptom of heart disease. That's especially true in women.

Sometimes, the first symptom is pain in the armpit. It's usually dull and achy. You may also have:

• Back pain
• Jaw pain
• Nausea
• A general feeling that something is wrong

Shingles

Shingles is a painful condition caused by the chickenpox virus (varicella-zoster). This virus stays in your body forever. It usually lies dormant in the nerve roots.

Sometimes, it reactivates and causes shingles. The first symptom is pain in the area served by that nerve (called a dermatome).

A few days later, a painful rash usually develops. It's confined to the dermatome, as well.

Reactivation in certain nerves can cause pain in or near the armpit.

Other Causes

• Benign (harmless) masses: These include cysts, lipomas, and fibroadenomas.
• Lymphedema: Disruption in the flow of lymph leads to a deep armpit ache and possibly swelling in that arm.
• Acid reflux: In some cases, pain is only felt in the armpit.
• Peripheral arterial disease (PAD): Narrowing of the major blood vessels supplying the arm.
• Menstrual period-related pain: Breast tenderness just before and during your menstrual periods may radiate to or only be felt in the armpit.

How to Check for Swollen Lymph Nodes and Armpit Lumps

To examine a lump under your armpit:

1. Lift your arm and gently place your fingers in your armpit.
2. Press on the center of the armpit and then palpate the area around it, going in front and back of the lump and along the chest wall.

Generally, a lump that is tender, soft, and moves around a little bit is less concerning than a firmer lump that is not tender and is fixed in place.

When to See a Healthcare Provider

You should see your healthcare provider for armpit pain if:

• The pain is severe
• It limits daily activities
• You have other concerning symptoms

Other concerning symptoms include:

• Night sweats
• A breast lump
• Unintentional weight loss

It's also important to seek prompt care if you have signs of an infection, such as:

• Fever and chills
• Redness
• Drainage

Even if your symptoms are mild but persist, make an appointment.

How Armpit Pain Is Diagnosed

Your healthcare provider has a range of tools for figuring out where armpit pain comes from. First, they'll likely ask a lot of questions about your pain and other symptoms. They'll want to know:

• The quality of the pain: Is it sharp or dull and achy, does it feel tingling, burning, or itchy?
• The duration: When did the pain begin? Is it constant or intermittent? Is it getting worse?
• The intensity: How severe is the pain on a scale of 1 to 10, with 1 being barely there, and 10 being the worst pain you can imagine?

Other questions may include:

• What other symptoms are you having? For example, fever or chills, night sweats, pain in other locations, or swollen lymph nodes in other locations?
• Have you had a rash or redness? Have you noted any other changes in your armpit?
• Have you had any scratches or cuts on your hand or arm?
• Have you started any new activities or sports?
• Have you recently had any type of injury?
• Have you used any new deodorants, lotions, bath soaps, or laundry detergents?
• When was your last mammogram? Do you have a family history of breast cancer? Have you noted any breast lumps?
• How much is the pain interfering with your daily life?

Next is a physical exam. Your healthcare provider will also look for any redness, rashes, lumps, or enlarged lymph nodes in your axilla. They'll probably also examine the areas surrounding your armpit. That includes your head and neck, arms, and chest.

They may perform a neurological exam to check for nerve compression. A breast exam can help determine if it's cancer. (Expect this regardless of your sex. Anyone can get breast cancer.)

Labs and Tests

The lab tests your provider orders depend on your symptoms and what they've found during a physical exam. You may be sent for a blood draw, urine test, or other types of testing. Tests may include:

• A complete blood count (CBC) to identify if there's an infection
• Inflammatory marker and antibody tests to reveal a possible autoimmune disease
• Skin scrapings to help identify rashes
• Allergy testing to confirm allergic contact dermatitis

Imaging

For some injuries, cancer, and other masses, you may have some imaging studies done. These may include:

• Ultrasound: Uses sound waves to create a picture of organs and other structures
• Computed tomography (CT) scan: Uses a series of X-rays to produce 3D images of bones and soft tissues
• Magnetic resonance imaging (MRI): Uses a magnetic field and radio waves to create detailed images of organs and tissues
• Positron emission tomography (PET) scan: Radioactive dye is injected to show diseased cells and abnormal activity
• Mammogram: A breast scan commonly used to detect tumors

Procedures

If no diagnosis has been made by this point, or it's not a firm diagnosis, your healthcare provider may opt for other diagnostic procedures.

An important one for axillary pain is a biopsy. That's when a small tissue sample is collected and sent to the lab for analysis. A biopsy is used to diagnose (or rule out) cancer.

Treatment for Causes of Armpit Pain

The treatment of armpit pain depends on the underlying cause.

How to Relieve Armpit Pain at Home

Armpit pain that is caused by muscle strain or other injuries may be relieved by things you can do on your own at home. However, it is best to consult with your healthcare provider to make sure you are on the right track.

Here's what you can do:

• Rest
• Ice the area
• Do gentle stretching
• Use over-the-counter splints, wraps, or braces (with a provider's advice)
• Take non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen

If the pain is caused by skin irritation, try to avoid any products (such as soaps or detergents) that may be responsible.

Medical Treatments for Armpit Pain

Medical treatments for armpit pain depend on the cause. Here are some common causes and their treatments:

• Rashes: Topical medications, antibiotics
• Infections: Topical and/or oral antibiotics
• Autoimmune disease: Immunosuppressants, arthritis medications (DMARDs)
• Cancer: Chemotherapy, radiation, hormone therapy
• Nerve compression: Standard injury treatments or, if they fail, surgery
• Heart disease: Clot-dissolving drugs, surgical treatments including bypass, radiofrequency ablation, stent placement, and angioplasty
• Shingles: Antiviral medications, painkillers, calamine lotion, oatmeal baths

Can You Prevent Armpit Pain?

Many causes of armpit pain can't be prevented. But some can. Here are some tips:

• Wear loose-fitting clothes and use hypo-allergenic or gentle products to avoid irritation.
• To avoid injury, warm-up properly before sports and avoid overusing your arm and shoulder.
• Keep the area dry to help prevent irritation and rashes.
• Report any rashes, possible infections, and other abnormalities right away so they don't get worse.

Summary

Armpit pain has many causes. They range from simple skin irritation or muscle strain to autoimmune disorders, heart disease, and cancer.

Diagnostic tests and treatment depend on your symptoms and what your healthcare provider finds or suspects.

Some causes of armpit pain can't be prevented. However, using gentle products, soft clothing, and doing a pre-exercise warm-up may help you avoid irritation, allergies, and injuries.

A Word From Verywell

If you don't have an obvious rash or injury, it may take some time to diagnose your armpit pain. Ask your provider how to safely treat this pain while you await a diagnosis and treatment plan. Most causes of armpit pain aren't serious and can be treated.