Why Your Armpit Hurts: Possible Causes Revealed

AAxillary or armpit pain can be due to various reasons. A Few are simple, like a muscle pull or a strain, but there are a few red flags that need attention by a specialist.

1. Musculoskeletal pain

Muscle pull, or a strain, is a common cause of armpit pain. Activities like lifting heavy weights, ^[1] throwing, playing tennis, and CrossFit exercises sometimes give rise to muscle strain, especially latissimus dorsi tear. Rest to the muscles, cold compresses simple painkillers and stretching help in the majority of cases. If pain persists beyond a few weeks or symptoms worsen, it's better to consult a specialist.

2. Lymphadenopathy

Lymph nodes are small organs that filter out foreign substances from our body and form an important part of the immune system. Most commonly, lymph node swelling is due to infection/inflammation. However, it may also be due to cancer or autoimmune diseases. When the lymph node becomes red, large and more painful, it is mostly due to pus formation. Infection is treated with antibiotics and painkillers but any swelling lasting for more than 3-4 weeks and more than 1-2 cm is abnormal and specialist help should be sought without delay.

3. Sebaceous cyst

Sebaceous cysts, also referred to as epidermal inclusion cysts, are typically harmless, slow-growing bumps felt under the skin. These typically form when a hair follicle sebaceous gland duct gets blocked.

MedBound Times contacted Dr Nitin B Shah, senior consultant surgeon, Mumbai who said "Complete excision along with cyst wall under local anesthesia prevents them from recurring". The sebaceous gland produces an oily substance called sebum. If the duct is blocked, sebum continues to be produced but has nowhere to go, and the sebaceous cyst is formed. "Most cysts resolve on their own but a few may become enlarged, red and painful, indicating infection". Consult a surgeon who may advise drainage/excision of the cyst. ^[2]

4. Skin conditions

Hidradenitis suppurativa: It is a chronic inflammatory skin condition characterized by painful lumps such as deep-seated nodules, abscesses, skin tunnels, and fibrotic scars. These manifestations primarily emerge in the axillary, groin, perianal, perineal, and inframammary regions. The condition's impact extends beyond physical discomfort, with associated pain, drainage, malodor, and scarring often leading to profound negative psychosocial implications for affected individuals, as per an original study published by NCBI.^[3] Treatment should be done by a dermatologist and may include lifestyle modifications, hormonal therapy, topical steroids, antibiotics, and minimizing skin irritative agents.

Intertrigo: Intertrigo is a superficial inflammatory skin condition that affects flexural surfaces, such as the axillae, abdominal folds, and perineum.

Dr. Prachi Ghuge Patil, a Dermatologist at Tejas Skin and Hair clinic, told MedBound Times , "This condition is often triggered or aggravated by warm temperatures, friction, moisture, maceration, and poor ventilation. The Latin origins of the term "intertrigo"—inter (meaning "between") and terere (meaning "to rub")—illustrate the condition's physiology." 

In cases of simple intertrigo, drying agents such as antiperspirants can help reduce moisture. After physical activity that leads to excessive perspiration, bathing or showering, followed by gentle drying with a soft towel, is recommended.

Allergic contact dermatitis: The armpit skin may have irritation due to soaps and detergents, deodorants, shaving creams, and sweating. Redness from shaving and rubbing of the skin with clothes (synthetic fabrics) may also cause a skin rash. Try switching to hypoallergenic products, keep the area clean and dry and consult a dermatologist if symptoms persist.

5. Autoimmune disorders

Some autoimmune disorders like Psoriasis, Rheumatoid arthritis, and Lupus are associated with skin lesions and cause armpit pain. The lesions of Psoriasis may become itchy, scaly, red and painful. "Treatment involves topical steroids and few lifestyle modifications as no particular cure for Psoriasis is known," says Dr Prachi.

6. Lymphoma

Now coming to the red flags, lymphoma is a type of cancer of the cells of the immune system called lymphocytes. It may start with lumps in the armpit, groin, and neck and usually has associated fever, generalized weakness, not feeling well, and pain which should prompt you to seek a specialist opinion. Treatment depends on the type and stage of lymphoma and includes chemotherapy, radiotherapy, bone marrow transplant along with supportive therapies.

7. Breast cancer

Breast cancer may present with a lump in the breast with pain or swelling in the armpit. ^[4] "It is extremely important to check if the armpit swelling is hard, non-rubbery and has associated symptoms like weight loss, night sweats and a family history of breast cancer," according to Dr Shah. Meticulous evaluation by a surgeon, tru-cut biopsy, staging and further management with or without chemotherapy/mastectomy is indicated.

Referred pain from the heart, and hormonal changes may also contribute to armpit pain. Any swelling/pain lasting for a longer time, swelling feeling hard and associated with fever, redness, or malaise mandates a specialist review to prevent further complications.

References:

1. Friedman MV, Stensby JD, Hillen TJ, Demertzis JL, Keener JD. Traumatic Tear of the Latissimus Dorsi Myotendinous Junction: Case Report of a CrossFit-Related Injury. Sports Health. 2015 Nov-Dec;7(6):548-52. doi: 10.1177/1941738115595975. Epub 2015 Jul 15. PMID: 26502450; PMCID: PMC4622375.

2. Zito PM, Scharf R. Epidermoid Cyst. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499974/

3. Ballard K, Shuman VL. Hidradenitis Suppurativa. [Updated 2024 May 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534867/

4. Menon G, Alkabban FM, Ferguson T. Breast Cancer. [Updated 2024 Feb 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482286/

By Dr Chahna Desai

^SSK