An armpit lump refers to enlargement of one or more lymph nodes under the arm.
Lump in the armpit; Localized lymphadenopathy - armpit; Axillary lymphadenopathy; Axillary lymph enlargement; Lymph nodes enlargement - axillary; Axillary abscess
Lumps in the armpit have various causes.
Lumps may occur when lymph nodes are swollen due to bacterial or viral infections,
Lymph nodes are filters that can catch infectious organisms or cancerous
- Bacterial infection
- Arm or breast infection
- Cat scratch disease
- Benign (harmless) cyst
Lipomas(harmless fatty growths)
- Normal breast tissue (breast tissue extends into the armpit area)
Allergic reactionpossibly caused by sulfa drugs, iodine, or penicillin Measles, mumps, rubella vaccine (rare)
- Smallpox vaccination
- Typhoid vaccine
- Viral infection
AIDS Chickenpox Infectious mononucleosis
- Shingles (
Home care depends on the reason for the lump. Check with your health care provider to determine the cause.
Call your health care provider if
Call if you have any unexplained armpit lumps. Do not try to diagnose lumps without professional help.
What to expect at your health care provider's office
Your health care provider will perform a physical examination and ask questions about your medical history and symptom, such as:
- When did you first notice the lump?
- Is it getting better, worse, or staying the same?
- Are you breastfeeding?
- Have you noticed any factors that make it worse?
- What other symptoms are also present?
- Is the lump painful?
The physical examination may include
Testing depends on what is found during the physical examination. Tests that may be done include:
- Blood tests, such as a complete blood count (
CBC) Kidney function tests Liver function tests Liver-spleen scan Lymph node biopsy Mammogram Platelet count X-ray of the chest
A lump in the armpit caused by a viral infection will eventually disappear without treatment. A lump in the armpit caused by an allergic reaction will go away after the "trigger" is removed. No treatment is necessary for a lump in the armpit caused by normal breast tissue. Usually, no treatment is necessary for a cyst.
A lump in the armpit caused by a lipoma is harmless, unless it grows so large that it causes discomfort.
The outlook for cancerous lumps depends on the specific type of cancer. See the following for more information:
Breast cancer Hodgkin's lymphoma Non-Hodgkin's lymphoma Leukemia
Armitage JO. Approach to the patient with lymphadenopathy and splenomegaly. In: Goldman L, Ausiello D, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 171.
Tower RL II, Camitta BM. Lymphadenopathy. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 484.