Armpit pain is often a sign of overexertion or muscle strain. However, it can indicate an underlying condition, such as an infection, lupus, or shingles.


The armpit is the point where the muscles that move the arms and shoulders connect with the bones. Some of these muscles also connect to the ribs.

Major nerves and blood vessels also pass through the armpits, and each armpit is home to several lymph nodes. Swollen lymph nodes typically indicate that a person has an infection, but sometimes, they can be a sign of cancer.

The skin under the arms is thin and contains many sweat glands. The warm, moist conditions may increase the risk of fungal or bacterial infections or rashes due to chafing.

This article covers some common causes of armpit pain.

A person stretching their arms up with one armpit visible.Share on Pinterest
Lucas Ottone/Stocksy

Many factors can contribute to or cause armpit pain, including some skin issues, infections, and immune conditions.

Muscle strain

Healthcare professionals describe muscle strain as an injury to the muscles or tendons. The fibers in the muscles and tendons may overstretch or tear.

People taking part in sports and activities that involve lifting, pulling, or throwing may injure muscles and experience armpit pain.

Strained pectoral (chest) muscles, which people use for lifting and pulling, can often cause underarm pain.

Damage to the coracobrachialis muscle, or upper arm muscle, may also cause armpit pain. This muscle assists people in throwing and pushing motions.

Swollen lymph nodes

When a person has an infection, the lymph nodes may swell. This causes the immune cells to go to that area to attack the infection, causing inflammation and pain.

Causes of swollen lymph nodes include:

Swollen lymph nodes typically go down within a few days or weeks. If the swelling lasts for more than 4 weeks, a person should contact a doctor.

Allergens and skin irritants

Many deodorants, antiperspirants, body washes, soaps, and laundry detergents contain skin irritants and allergens.

Some of these may lead to allergic contact dermatitis, a condition that causes itching, burning, and tiny blisters. People typically get the rash 1–2 days after coming into contact with the allergen.

Irritant contact dermatitis can result in an itchy rash, stinging, pain, swelling, and heat. As the reaction is almost immediate, people can often quickly identify what irritates their skin.

Bacterial and fungal infections

Ringworm, or tinea, is a common fungal infection affecting the uppermost layer of skin. It triggers a discolored, ring-shaped rash. Ringworm rashes can be painful and lead to inflamed, itchy, and scaling skin.

As fungi thrive in warm, moist environments, the armpit is an ideal location for the infections that fungi can cause.

Bacteria flourish in moisture and warmth, so bacterial infections can develop quickly and contribute to inflammation and pain in the area.

Intertrigo

Friction and moisture in the folds of the skin can lead to a type of inflammation called intertrigo. Symptoms of intertrigo include itchy skin, pain, tingling, and burning in the affected area.

Without treatment, secondary bacterial or fungal infections may also develop, causing further pain.

Cysts

Cysts are painful lumps that can develop when bodily fluids build up in the armpits.

Staphylococcus bacteria, which typically live on the skin, can cause an infection to develop in the cysts.

Cancer

The lymph nodes in the chest, including those in the armpits, often work extremely hard when cancer develops in the upper body.

In particular, painful lymph nodes develop in response to breast cancer, lymphomas, and respiratory cancers.

Some people may also experience painful lymph nodes as a side effect of cancer treatments, such as radiation therapy, chemotherapy, and surgery.

Cancers that commonly cause armpit pain include:

Lipomas

A lipoma is a lump of fatty tissue that feels rubbery. A person can move it around under the skin. Most lipomas are noncancerous and do not cause pain.

However, lipomas that grow rapidly can cause pain by putting pressure on nerves or blood vessels. In these cases, a healthcare professional may recommend surgery to remove the growth.

Boils or ingrown hairs

When inflammation occurs in a single hair follicle, a boil or furuncle may develop. Boils are discolored, swollen lumps that are tender to the touch.

When neighboring hair follicles become infected, the underlying tissue may feel inflamed and painful.

Diabetes

Diabetes can cause neuropathy, or nerve damage. A common symptom of neuropathy is burning pain in the affected body part.

Diabetic neuropathy may develop in people whose blood sugars are consistently high.

Some autoimmune conditions

Lupus is a long-term (chronic) autoimmune condition that causes inflammation throughout the body, including in the lymph nodes.

Rheumatoid arthritis is another example. This condition can lead to swelling and inflammation of the inner tissues of the joints, which may affect the armpit.

Psoriasis is an autoimmune condition that has effects on the skin on various parts of the body, including the armpit area. It can lead to different types of plaque or scale developing on the skin, as well as itching, discomfort, and pain.

Hidradenitis suppurativa

Hidradenitis suppurativa is a chronic condition that causes inflammation of the sweat glands beneath the hair follicles. It often affects the armpits and groin, where the skin rubs together.

Symptoms typically begin as pimple-like bumps or blisters that turn into cysts and boils. Eventually, these may burst and leave scars as they heal.

Shingles

Shingles causes a painful and scaly rash that often affects the chest, back, and armpits.

The rash typically clears within 7–10 days.

Peripheral artery disease

Peripheral artery disease narrows the blood vessels carrying blood away from the heart. It is more common in the legs but can affect the arms.

Arteries carry oxygen-rich blood to the muscles. Without oxygen, muscle cells begin to wither and die, which can cause intense pain.

Breast cancer

Swelling or lumps around the collarbone and armpit may indicate that breast cancer has spread to the lymph nodes. Occasionally, this is the first sign of the disease.

Doctors may recommend a biopsy to find out whether the nodes contain cancer. If they do, a surgeon will likely remove them.

Breast cancer resources

Visit our dedicated hub for more research-backed information and in-depth resources on breast cancer.

People should seek medical attention if armpit pain worsens or interferes with daily life.

People should consult with a doctor if they have:

If armpit pain occurs with lumps and soreness in the area, it may indicate a serious infection or immune condition.

A person can soothe or help prevent some armpit pain by:

  • using a cold compress to reduce muscle soreness
  • taking over-the-counter anti-inflammatory medications such as ibuprofen
  • getting a massage, as it may help promote circulation and reduce swelling
  • using a warm compress, as this may reduce lymph node swelling and ease pain
  • using topical steroids, or antifungal or medicated creams, to treat any underlying skin conditions that cause armpit pain
  • applying moisturizers with glycerin or other hydrating properties, which can help prevent excessive dryness and related skin conditions
  • keeping the armpits clean to help prevent infection
  • avoiding body washes, soaps, and detergents that contain allergens or irritants, and instead using gentle, fragrance-free products
  • avoiding excessive exposure to hot temperatures, which can help prevent excess moisture and warmth in the armpits
  • taking quick, lukewarm baths and showers
  • wearing loose-fitting clothing, as this can help prevent chafing
  • not shaving the armpits too often, as doing so can cause irritation, nicks, and cuts
  • not sharing personal hygiene tools or products to minimize the risk of bacterial infections

The best treatment option for armpit pain depends on the cause. If a healthcare professional suspects infection, muscle strain, or illness, they will almost always suggest rest.

Armpit pain that occurs due to cancer or any of its treatments may require anti-inflammatory and pain medications.

Managing immune activity with conditions such as lupus and rheumatoid arthritis often helps reduce armpit pain.

Armpit pain may result from an accidental injury or infection and may not be completely preventable. However, people can take steps to reduce the risks of certain causes of armpit pain.

People can reduce the risk of muscle strain by warming up thoroughly before exercising and taking care when lifting or throwing heavy objects.

People with skin infections or rashes may be able to identify anything they are allergic to and avoid using it. Keeping the underarm area clean and dry can reduce the risk of bacterial and fungal infections.

By managing blood sugar levels, people with diabetes may reduce the risk of diabetic neuropathy.

Armpit pain is typically a sign of a strained muscle, minor infection, or skin condition. Occasionally, it can be a symptom of a more serious underlying condition, such as cancer.

Some people may have rashes, boils, blisters, or sores on their skin, while others may have no visible symptoms.

People should seek medical help if the pain is severe, long lasting, or interferes with their daily life.