Underarm Pain: Possible Causes, Symptoms, Diagnosis, Treatment, Prevention and Overview

The cause could be one of several conditions, ranging from skin irritation caused by shaving to lymphedema or breast cancer.

Read on to learn more about your pain’s possible causes and treatments.

Causes of armpit pain

Your armpit pain could be caused by something temporary, or it could be a warning sign for a more severe condition.

Here are some of the common causes of armpit pain:

Muscle strain

Several muscles in the chest and arms can cause underarm pain from overuse or injury.

The pectoralis major is a sizeable thoracic muscle that extends to the shoulder. You can be injured playing sports or lifting weights.

The coracobrachialis is a muscle in the upper arm that can also be strained during sports, such as baseball, or other activities, such as tennis.


If any of these muscles in your chest or upper arm contract or become inflamed, you may feel pain in your armpit.

Skin conditions

Shaving or waxing under your arms can irritate your skin.

Sure, deodorants or laundry detergents can trigger an allergic reaction. That can cause a rash called contact dermatitis. These skin conditions are usually minor and temporary problems.

Rashes, bumps, and other skin problems can also result from more severe health problems.

For example, hidradenitis suppurativa looks like underarm acne, but it’s a more severe problem that can cause scarring. Fluid can also be released if sprouts break.


Shingle is a skin-related condition that can cause armpit pain.

It is an infection transmitted by the varicella-zoster virus. Shingles cause an uncomfortable, scaly rash that usually appears on the back, chest, or under the arms.

The virus can also cause a burning or tingling sensation.

Swollen lymph nodes

Your lymphatic system is a network of nodes or glands found throughout the body. Lymph is a fluid that helps fight infection.

There is a concentration of lymph nodes near the armpit on both sides of the body.

Your lymph nodes may become swollen and tender if you have a cold or the flu. There are also several types of lymphatic conditions that can cause armpit pain.

Lymphedema, for example, occurs when there is a blockage in a lymph node, and the fluid inside accumulates. This swelling can be excruciating.

Lymphedema can follow breast cancer treatment or the removal of some lymph nodes that may have become cancerous.

Another condition, lymphadenopathy, also causes the lymph nodes to enlarge. It is caused by an infection of the lymphatic system called lymphadenitis.

Breast cancer

Breast cancer is often painless in its early stages, but if you notice pain or feel a lump under your arm or breast, make an appointment with your doctor.

The cause of the discomfort may be benign growth, and it is not something to worry about, but it still needs to be checked.

Peripheral arterial disease (PAD)

PAD is a narrowing of the smaller arteries in the arms and legs. This causes less oxygenated blood to reach the muscles and tissue in the extremities.

Oxygen-starved muscles ache. If you have PAD in one or both arms, you may feel this pain in your armpit.


Depending on the cause of the pain in your armpit, the symptoms can be very different.

Skin conditions, such as inflamed hair follicles or shingles, will cause prominent rashes or other visible symptoms.

Lymph node disorders can cause swelling in the arm or armpit. You may also experience pain or swelling in your abdomen or legs if other lymph nodes are affected.

Signs of breast cancer can include changes in the shape and size of the breast. Dimples in the skin of the breast, known as peau d’orange, and changes in the appearance of the nipple can also occur.

The armpits can be painful due to problems with the skin or tissues with deeper structures. Underarm skin is prone to irritation from constant moisture and rubbing throughout the day.

As for the deeper structures, the armpit contains some of the body’s lymph nodes responsible for draining fluids and waste products from other parts of the body.

Lymph nodes play an essential role in clearing local or systemic infections.

The armpit also contains nerves that can become compressed, causing pain. In addition, due to the location near the breast, the processes that affect the breasts can also affect the armpits.

Associated armpit pain symptoms include:

  • Enlarged lymph nodes
  • Eruption.
  • Itch.
  • Pain in the breasts
  • Systemic symptoms such as fever, sweating, and fatigue.
  • Drain fluid.
  • Red streaks on the skin.

When to see a doctor?

Underarm pain related to a muscle strain may heal on its own after resting your muscles for a few days. If you have other symptoms, such as swelling or the presence of a lump, you should see your doctor.

You may be referred to a hematologist specializing in lymph node disorders or a breast cancer specialist if cancer is suspected.

See a dermatologist if you see a rash or other signs of underarm skin problems.

If you suspect a lymph node disorder and have symptoms such as fever or congestion, you may have a respiratory infection related to his lymph nodes.

Early treatment of any condition will lead to better results in most cases. If the pain is a temporary muscle-related problem, getting a diagnosis can alleviate some anxiety.

If you have armpit pain that lasts for more than a few days or other symptoms, such as swelling or a rash, see a doctor right away.

Diagnosis of pain in the armpits

Your doctor will examine your armpit and ask about other symptoms you have.

You will also want to know when the armpit pain started. They can also examine your throat, ears, and skin to help with the diagnosis.

If they suspect a lymph node disorder or breast cancer, you may need a blood test and possibly a tissue biopsy from a lymph node or, if present, a lump.

The blood test may include a complete blood count (CBC) and a test for specific markers of the suspected condition.


Treating a stretched muscle generally involves ice and rest for the first few days. As the pain subsides, you can apply heat to help improve circulation to the area. Light stretching can also increase circulation.

Treatment for shingles may include:

  • Antiviral drugs: such as acyclovir (Zovirax), valaciclovir (Valtrex)
  • Famciclovir (Famvir) kills the virus and keeps symptoms under control.

If the pain is too bad, it may be necessary to use capsaicin cream or numbing medications, such as lidocaine (AneCream, LMX 4, LMX 5, RectaSmoothe, RectiCare).

Hidradenitis suppurativa is treated with antibiotics and acne-fighting medications. If the condition does not respond to medications, surgery may be necessary.

Treatment for swollen lymph nodes depends on the cause. A bacterial infection will require antibiotics, while a viral infection will generally only need time to resolve.

Sometimes a warm, wet washcloth applied to the affected part of the armpit can reduce pain.

If pain is a symptom of breast cancer, treatment may include surgery to remove the tumor or affected lymph nodes, chemotherapy, or radiation.

Prevention of pain in the armpits

Preventing breast cancer or lymphatic disorders can be impossible, although having yearly exams can help you get diagnosed early.

Other causes of armpit pain can be avoided with a few precautions. For example, you can prevent a stretched muscle by stretching and not pushing yourself beyond your abilities in the weight room.

The shingles vaccine is not 100 percent effective, especially as you age, but it can significantly reduce your chances of infection with the virus.

Other less serious skin problems, such as contact dermatitis, can be prevented by changing deodorants, antiperspirant products, or detergents bothering your skin.

You want to practice good skin hygiene in areas that can trap oil, sweat, and dirt. Keep your armpits clean, and don’t wait to see a doctor if you notice a rash or other problem.


Many conditions that can cause armpit pain, such as shingles or a pulled muscle, are manageable and usually temporary, lasting from several days to a few weeks.

Breast cancer or problems with your lymph nodes can be life-threatening, but treatment options continue to improve your chances of survival. This is especially the case if the cancer is diagnosed and treated in its early stages.

See your doctor if the pain lasts more than a few days.