Painless Armpit Lump Symptoms, Causes & Common Questions
Try our free symptom checker
Get a thorough self-assessment before your visit to the doctor.
Are you experiencing a painless lump under your armpit? Read more below to learn 9 possible causes, questions your doctor may ask, and more.
9 causes of painless armpit lumps
This list does not constitute medical advice and may not accurately represent what you have.
A cyst is a small sac or lump, filled with fluid, air, fat, or other material, that begins to grow somewhere in the body for no apparent reason. A skin cyst is one that forms just beneath the skin.
It's believed that skin cysts form around trapped keratin cells – the cells that form the relatively tough outer layer of the skin.
These cysts are not contagious.
Anyone can get a skin cyst, but they are most common in those who are over age 18, have acne, or have injured the skin.
Symptoms include the appearance of a small, rounded lump under the skin. Cysts are normally painless unless infected, when they will be reddened and sore and contain pus.
Diagnosis is made through physical examination. A small cyst can be left alone, though if it is unsightly or large enough to interfere with movement it can be removed in a simple procedure done in a doctor's office. An infected cyst must be treated so that the infection does not spread.
Top Symptoms: skin-colored armpit bump, marble sized armpit lump, small armpit lump
Symptoms that always occur with skin cyst: skin-colored armpit bump
Urgency: Wait and watch
Lipoma is a word that translates as "fatty tumor," but a lipoma is not cancer. It is simply a growth of fat between the muscle layer and the skin above it.
The exact cause is not known. The condition does run in families and is associated with other unusual syndromes such as adiposis dolorosa, which is similar. Lipomas most often appear after age 40.
Symptoms include a soft, easily moveable lump beneath the skin, about two inches across. A lipoma is painless unless its growth is irritating the nerves around it. They are most often found on the back, neck, and abdomen, and sometimes the arms and upper legs.
It is a good idea to have any new or unusual growth checked by a medical provider, just to make certain it is benign.
Diagnosis is made through physical examination, biopsy, and imaging such as ultrasound or CT scan.
Most of the time, treatment is not necessary unless the lipoma is unsightly or is interfering with other structures. It can be removed through surgery or liposuction.
Top Symptoms: skin-colored groin bump, marble sized groin lump, small groin lump
Symptoms that always occur with lipoma: skin-colored groin bump
Urgency: Wait and watch
Enlarged lymph nodes in the armpit
Enlarged lymph nodes occur when the node becomes larger as it fills with inflammatory cells. This often is a result of an infection but can occur without a known cause.
Top Symptoms: armpit lump, movable armpit lump
Symptoms that always occur with enlarged lymph nodes in the armpit: armpit lump
Symptoms that never occur with enlarged lymph nodes in the armpit: fever, unintentional weight loss, hard lump in the armpit
Urgency: Phone call or in-person visit
Folliculitis is a common skin problem where hair follicles are infected by bacteria or fungi.
Top Symptoms: small facial lump, pink or red facial bump, face itch, facial bump leaking yellow/milky fluid, yellow or white facial bump
Symptoms that always occur with folliculitis: small facial lump
A furuncle, also called a boil, is infection of a hair follicle. The infection forms under the skin at the root of the hair and may occur anywhere on the body.
The infection is caused by bacteria, most often Staphylococcus aureus or "staph." Irritation caused by clothes or anything else rubbing the skin can cause the skin to break down and allow bacteria to enter.
Staph bacteria are found everywhere. Frequent and thorough handwashing, and otherwise maintaining cleanliness, will help to prevent its spread.
Most susceptible are those with a weakened immune system; diabetes; and other skin infections.
Symptoms include a single bump under the skin that is swollen, painful, and red, and contains pus.
It is important to treat the boil, since infection can spread into the bloodstream and travel throughout the body.
Diagnosis is made through physical examination and sometimes fluid sample from the boil.
Treatment may involve incision and drainage of the infection, followed by creams to apply to the site of the boil and/or a course of antibiotic medicine.
Top Symptoms: pink or red facial bump, small facial lump, painful facial bump, marble sized facial lump, constant skin changes
Symptoms that always occur with boil (furuncle): pink or red facial bump
Symptoms that never occur with boil (furuncle): fever
Pimples are also called comedones, spots, blemishes, or "zits." Medically, they are small skin eruptions filled with oil, dead skin cells, and bacteria.
Pimples often first start appearing at puberty, when hormones increase the production of oil in the skin and sometimes clog the pores.
Most susceptible are teenagers from about ages 13 to 17.
Symptoms include blocked pores that may appear flat and black on the surface, because the oil darkens when exposed to the air; blocked pores that appear white on the surface because they have closed over with dead skin cells; or swollen, yellow-white, pus-filled blisters surrounded by reddened skin.
Outbreaks of pimples on the skin can interfere with quality of life, making the person self-conscious about their appearance and causing pain and discomfort in the skin. A medical provider can help to manage the condition, sometimes through referral to a dermatologist.
Diagnosis is made through physical examination.
Treatment involves improving diet; keeping the skin, hair, washcloths, and towels very clean; and using over-the-counter acne remedies.
Top Symptoms: pink or red facial bump, small facial lump, painful facial bump, marble sized facial lump
Symptoms that always occur with pimple: pink or red facial bump
A skin abscess is a large pocket of pus that has formed just beneath the skin. It is caused by bacteria getting under the skin, usually through a small cut or scratch, and beginning to multiply. The body fights the invasion with white blood cells, which kill some of the infected tissue but form pus within the cavity that remains.
Symptoms include a large, red, swollen, painful lump of pus anywhere on the body beneath the skin. There may be fever, chills, and body aches from the infection.
If not treated, there is the risk of an abscess enlarging, spreading, and causing serious illness.
Diagnosis is made through physical examination.
A small abscess may heal on its own, through the body's immune system. But some will need to be drained or lanced in a medical provider's office so that the pus can be cleaned out. Antibiotics are usually prescribed.
Keeping the skin clean, and using only clean clothes and towels, will help to make sure that the abscess does not recur.
Top Symptoms: rash with bumps or blisters, red rash, red skin bump larger than 1/2 cm in diameter, pus-filled rash, rash
Symptoms that always occur with skin abscess: rash with bumps or blisters
Urgency: Primary care doctor
Allergic contact dermatitis of the armpit
Allergic contact dermatitis is a condition in which the skin becomes irritated and inflamed following physical contact with an allergen. Common products known to cause allergic dermatitis include plants, metals, soap, fragrance, and cosmetics.
Top Symptoms: armpit redness, armpit itch, scabbed armpit bump
Symptoms that always occur with allergic contact dermatitis of the armpit: armpit redness
Hodgkin lymphoma, formerly known as Hodgkin's lymphoma or Hodgkin's disease, is cancer of the lymphatic system. It is believed to be caused by a mutation in one of the body's immune system cells, called a B cell.
Most susceptible are those under age 30 or over age 55, with a family history of the disease, as well as anyone with a history of any illness caused by the Epstein-Barr virus.
Symptoms include swelling of lymph nodes in groin, armpits, and neck; lowered tolerance to drinking alcohol, including pain in lymph nodes afterwards; unintended weight loss; fever; chills; night sweats; and itching.
There are good treatments available for Hodgkin lymphoma, so it is important to see a medical provider about these symptoms as soon as possible.
Diagnosis is made through physical examination; blood tests; imaging such as x-ray, CT scan, or PET scan; and sometimes lymph node biopsy and/or bone marrow sample.
Treatment involves a combination of chemotherapy and radiation therapy. Bone marrow transplant, also called stem cell transplant, can be done in some cases.
Top Symptoms: fatigue, loss of appetite, abdominal pain (stomach ache), shortness of breath, fever
Symptoms that never occur with hodgkin's lymphoma: pulsing armpit mass, armpit lump that comes and goes, shrinking armpit lump, pink or red armpit bump, black or brown armpit bump, yellow or white armpit bump, bleeding armpit bump
Urgency: Primary care doctor
Questions your doctor may ask about painless armpit lump
- What color is the bump?
- Any fever today or during the last week?
- Do you have a rash?
- Are you experiencing a headache?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
Painless armpit lump symptom checker statistics
People who have experienced painless armpit lump have also experienced:
- 9% Hard Lump In The Armpit
- 7% Fatigue
- 4% Armpit Lump
People who have experienced painless armpit lump were most often matched with:
- 100% Enlarged Lymph Nodes In The Armpit
People who have experienced painless armpit lump had symptoms persist for:
- 43% Less than a week
- 21% Over a month
- 13% Less than a day
Source: Aggregated and anonymized results from Buoy Assistant.