There are a variety of conditions which can cause pain in the armpits, ranging from the common cold to chronic conditions.
This article explore the common causes of underarm pain, when to see a doctor, and how armpit pain may be treated.
Common causes of armpit pain
Wide-ranging factors contribute to or cause underarm or armpit pain, including skin conditions, infections, and immune conditions.
Depending on the cause and severity, symptoms vary from mildly irritating to extremely uncomfortable and distressing.
Common causes of underarm pain include:
Swollen lymph nodes
The lymph nodes are crucial to a successful immune response. They round-up foreign bodies and stimulate the release of immune cells, which destroy and remove these invading bodies.
During bacterial, fungal, and viral infections, the lymph nodes fill up with invading cells and begin to swell. This enlargement causes inflammation and pain.
Causes of swollen lymph nodes include:
- the common cold
- upper respiratory infection
- viral infection
- strep throat
- ear infection
- tooth infection
- wounds and skin infections
Allergens and skin irritants
Many deodorants, antiperspirants, body washes, soaps, and laundry detergents contain known skin irritants and allergens.
Some irritants and allergens lead to allergic contact dermatitis, a condition that causes redness and tiny blisters.
Similarly, irritant contact dermatitis can result in redness, pain, swelling, and heat.
Pets and environmental factors also carry known allergens that cause an immune response and, by extension, armpit pain.
Psoriasis is an autoimmune condition that affects the armpits, causing reddish-brown skin plaques that are covered by silvery or shiny scales.
Psoriasis symptoms can be extremely uncomfortable and painful, especially if subjected to friction and moisture, which may occur in the armpit.
Similar to fungi, bacteria thrive in warm, moist environments.
Tinea corporis (ringworm of the body)
Ringworm is a common fungal infection of the uppermost layer of the skin that leaves behind a red, ring-shaped rash.
As fungi thrive in warm, moist environments, the armpit is a target for the infections that the fungi can cause.
Ringworm fungi also use the keratin found in hair as food. Ringworm rashes can be painful and lead to inflamed, itchy, and scaling skin.
Intertrigo is a skin inflammation caused by friction and moisture in folds of the skin. It results in redness, pain, burning, and may have an unpleasant odor. Secondary bacteria or fungal infections occur if it is left untreated.
Candidia species is a type of yeast that can cause intertrigo. It can turn the skin red with white plaques.
There are several armpit muscles with underlying connective tissues, arteries, veins, and bones.
Strained pectoral or chest muscles, which are used for lifting and pulling, can often cause underarm pain. Damage to the coracobrachialis muscle or upper arm muscle, which is used to throw and push, may also cause underarm pain.
The lymph nodes in the armpit may swell or be painful if a person has cancer, or is receiving cancer treatments.
The lymph nodes in the chest, including those in the armpits, often work overtime when cancer affects the upper body.
Persistent lymph node pain usually accompanies breast, lymph, and respiratory cancers, in particular. Lymph node pain is often a side effect of cancer treatments, such as radiation, chemotherapy, and surgery.
Cancers that commonly cause armpit pain include:
- lymphoma or cancer of the lymphatic system
- leukemia or cancer of the blood-forming tissues, including the lymphatic system and bone marrow
- cancers that have spread from another organ or part of the body
Indigestion, where stomach acids travel back up to the food pipe, can cause shooting and sharp pain in the chest and occasionally in the armpit.
These are when body fluids accumulate in the armpits, causing swelling and pain. Cysts can become infected, especially by Staphylococcus bacteria, which usually live on the skin.
A lump of fatty tissue that feels rubbery and is mobile or movable, is called a lipoma. Most lipomas are non-cancerous and not painful. Lipomas that grow rapidly can cause pain by affecting nerves or blood vessels - people should seek medical attention for any of these.
Inflamed hair follicle (boil), or ingrown hairs
When a single hair follicle becomes infected, a boil or furuncle may develop. Boils are swollen, red lumps that are tender to touch. When neighboring hair follicles become infected, the underlying tissue may become inflamed and painful.
This chronic immune condition causes inflammation throughout the body, including the lymph nodes.
Another chronic immune disease, rheumatoid arthritis leads to swelling and inflammation in the inner tissues of the joints, which may include the armpit.
This is a chronic condition that causes inflammation of the sweat glands associated with hair follicles.
Symptoms usually begin as pimple-like bumps or blisters that turn into cysts and boils. Eventually, these wounds may break, weep, and form tunnels under the skin.
Early medical attention and treatment are recommended to avoid unsightly scarring and potential infection.
Shingles and the herpes zoster virus
Shingles can cause a burning sensation in the armpit, accompanied by a painful rash.
Shingles causes a painful and scaly rash that often affects the chest, back, and underarm. Shingles, which is caused by the herpes zoster virus, can also cause a burning or tingling sensation in the skin and underlying tissues.
Peripheral artery disease
PAD narrows the small blood vessels of the arms and legs, reducing oxygen flow to the surrounding tissues. Oxygen-deprived muscles and cells begin to whither and die, which is a very painful process.
When to see a doctor
A person should seek medical attention if armpit pain becomes severe or interferes with everyday activities.
Minor and reversible health complications, such as common colds, muscle soreness, and bacterial infections are the most common reasons for pain in the region.
But armpit pain, lumps, and soreness can be a sign of serious infections and immune conditions, including cancer and HIV.
Though rare, serious health complications include:
- some sexually transmitted infections, especially syphilis
- cat scratch fever caused by a bacterial infection from a cat scratch or bite
- toxoplasmosis, a virus found in uncooked meat and cat feces
Symptoms that may be a sign of more severe health risks that require medical attention include:
- swollen lymph nodes that last for more than 1 or 2 weeks without a known cause
- extremely sore armpit region or lymph nodes that may be tender to touch
- swelling of multiple lymph nodes in the body, such as in the groin, head, and neck
- fever and night sweats
- hard lumps in the armpit region or lymph nodes
- difficulty breathing and swallowing
- unexplained weight loss
- constipation or altered bowel movements
- unexplained continuous exhaustion
Treating armpit pain
The first line of recommended treatment for armpit pain depends on the suspected cause. If infection or illness is suspected, a doctor will almost always advise rest.
Common ways to help ease or prevent armpit pain include:
- Using ice compresses to reduce muscle soreness. Anti-inflammatory medications, including ibuprofen, may also be helpful to decrease inflammation and associated pain. Massage helps promote circulation and can reduce swelling.
- Using a warm compress to ease lymph node swelling and pain.
- Using topical steroids, anti-fungal, or medicated creams to treat the underlying skin condition that causes armpit pain.
- Applying moisturizers to prevent excessive dryness and related skin conditions. Use products that contain glycerin or other hydrating properties, as these will soak into the skin. Products that leave behind a residue could clog pores and prompt sweating.
- Keeping the armpit clean to prevent infection.
- Avoiding heavy body washes, soaps, and detergents that contain allergens or irritants.
- Avoiding excessive exposure to hot water or weather to avoid sweating.
- Taking quick lukewarm baths and showers instead of hot drawn out sessions.
- Wearing loose-fitting clothing to avoid chafing.
- Avoiding shaving, especially with a razor that may cause further irritation, as well as nicks and cuts.
- Not sharing personal hygiene tools or products to avoid bacterial infections.
Armpit pain associated with cancer or cancer treatments may require anti-inflammatory and pain medications. Controlling immune conditions, including lupus and rheumatoid arthritis, often helps lessen armpit pain.
In some people, especially those whose immune systems are weakened, lymph nodes may become infected and require medical intervention. If they go untreated, the moderate to severe health risks include:
- Abscess. When a lymph node becomes overworked, then invading cells, immune cells, and dead tissues may build up, allowing bacteria to form a pocket of pus. Abscesses can be very painful and may require antibiotics and drainage.
- Bacteremia (infection of the bloodstream). Untreated bacterial infections, especially those of the lymph nodes, can infect the bloodstream, causing sepsis. Sepsis can be life-threatening and needs hospital treatment. Without proper treatment, sepsis can lead to organ failure and, ultimately, death.