Armpit Pain: Causes, Treatment, and More (2024)

Many things can cause pain in one or both of your armpits, including muscle strain, swollen lymph nodes, or, in some cases, cancer. Finding the cause can be crucial to avoid complications.

Armpit pain can occur for many different reasons. Causes of armpit pain can range from minor issues such as skin irritation from shaving and muscle pulls to serious conditions like breast cancer.

Keep reading to learn more about the possible causes and treatments for your pain.

Several muscles in your chest and arms could cause armpit pain from overuse or injury.

An injury can occur to the pectoralis major (a large chest muscle that runs up into your shoulder) while playing sports or lifting weights. You might strain the coracobrachialis (a muscle in your upper arm) during sports, such as baseball or tennis.

If you sprain any of these or other muscles of your chest or upper arm, you could feel the pain in the armpit.

Treating a strained muscle usually involves ice and rest for the first few days. As the pain subsides, you may apply heat to help improve circulation in the area. Light stretching can also boost circulation.

Learn more: Muscle strain treatment.

Your lymphatic system is a network of nodes or glands throughout your body. These nodes produce a fluid that helps fight infections.

Many lymph nodes are present near your armpit on both sides of the body, and if these swell, they may cause pain in your armpits. This usually happens when your body is fighting a pathogen or because of other types of lymph node disorders or diseases affecting the lymph nodes.

Causes of swollen lymph nodes include:

• viral infection like the flu
• lymphedema
• HIV
• lymphadenitis
• Eczema herpeticum
• shingles
• skin infection
• leukemia or skin cancer, such as melanoma or sarcoma

Lymph node disorders can cause swelling in the arm or armpit. If they affect other lymph nodes, pain or swelling may occur in your abdomen or legs. The treatment for swollen lymph nodes depends on the cause.

While cancer can cause swollen lymph nodes, it can also cause armpit pain in other ways. For example, breast cancer may cause swelling in your armpit, breast, or collarbone related to the cancer itself. If you notice pain or feel a lump at these sites, make an appointment with your doctor.

Other cancers can affect the armpit area, such as cutaneous T-cell lymphoma, which can cause both swollen lymph nodes and irritation to the skin under your arm, affecting that area.

Autoimmune diseases can inflame your lymph nodes or cause flare-ups in your nerves and joints in your arms and shoulders.

Examples of such conditions include:

• lupus
• rheumatoid arthritis
• psoriasis
• sarcoidosis
• autoimmune lymphoproliferative syndrome

Learn more: Everything to know about autoimmune diseases.

Axillary nerve dysfunction, which is a type of peripheral neuropathy, can cause armpit pain.

Specifically, you can experience radial nerve dysfunction or a pinched nerve. Your radial nerve begins at your armpit and goes down through your arm to your hand. Damage to this nerve can feel like numbness, but depending on the cause, it can also cause pain. This may affect the armpit.

Autoimmune disease is one possible cause of neuropathy. Others include:

• serious injury like blunt trauma or perforation.
• diabetes
• alcohol misuse
• medication side effects
• infection

Learn more: What you should know about neuropathic pain.

Skin rashes that affect the skin under your arms may cause you armpit pain. This can include an allergic reaction in your armpits to products like deodorants or laundry detergents, known as contact dermatitis.

Bacterial infection such as ringworm, or a fungal infection such as cutaneous candidiasis may also cause armpit pain.

Other skin-related causes include:

• razor burn
• intertrigo
• folliculitis
• inverse psoriasis
• hidradenitis suppurativa

Learn more: Types of armpit rash and how to treat them.

A lipoma is a fatty tissue growth under the skin that is usually not cancerous. It can develop in your armpit.

It’s usually harmless and doesn’t need treatment. It’s also usually not painful. That said, you might experience some pain, especially if you put pressure on the lump when lowering your arm.

If it’s causing you significant discomfort, see your doctor, as there are treatments, and it may be possible to remove it. It’s also a good idea to rule out other more serious causes, such as cancer.

Learn more: Lipoma (skin lumps).

When you shave, the ends of your hair can become blunt and hard, which makes it more likely to curl back into the skin instead of growing outward. This can cause ingrown hairs.

Ingrown hair can develop anywhere you choose to remove hair, such as armpits. They can cause discomfort and may become more painful if they turn into cysts or contract an infection.

There are home remedies to help them go away faster, but you’ll need medical treatment for a cyst or an infection.

Learn more: Taking care of ingrown underarm hair.

PAD is the narrowing of your smaller arteries in the arms and legs. It causes less oxygenated blood to reach the muscles and tissue of your limbs.

Oxygen-starved muscles hurt. If you have PAD in one or both arms, you might feel pain in your armpit.

Various medications and lifestyle changes, such as exercising regularly and eating a balanced diet, can help manage this condition.

Learn more: Treatment options for peripheral artery disease.

When should I be concerned about armpit pain?

If you experience worsening armpit pain that negatively affects your daily life, it’s important that you consult a doctor.

Certain symptoms and armpit pain warrant a checkup, including prolonged swelling or hard lumps in your armpits or any painful skin rash that doesn’t go away. In addition, if you have other unusual symptoms, see a doctor right away.

Can deodorant cause armpit pain?

Deodorant could cause armpit pain if you have an allergy or sensitivity to any of its ingredients.

Can underarm pain be heart-related?

When you experience a heart attack, it’s possible to experience pain in your shoulder and armpit.

Armpit pain can have many causes. If it’s related to a muscle strain it might be able to heal on its own after you rest your muscles for a few days. However, if you have other symptoms, like swelling or the presence of a lump, you should see your doctor.

Early treatment of any condition leads to better outcomes in most cases. If the pain is a temporary muscle-related problem, getting a diagnosis can also ease some anxiety.

Read this article in Spanish.