Armpit lump after shaving: what to know

Shaving can nick the skin and trap a curling hair beneath it. A surface bump that is red, tender, or centred on a hair is different from a deeper swelling that has no visible skin change.

Small shaving-related bumps often involve inflammation around a hair follicle. Warmth, pus, increasing redness, or throbbing can point to infection. Lymph nodes sit deeper in the armpit and can enlarge while the immune system responds to nearby skin irritation or infection.

Breast cancer can present with an armpit node, and lymphoma can present with enlarged lymph nodes, but touch alone cannot identify the cause. A clinician considers the skin, breast or chest area, recent illness, medicines, and whether the lump is changing.

Pause shaving and avoid deodorants that sting until the skin settles. Wash gently, use a warm compress for comfort, and wear loose clothing. Do not squeeze, pierce, or repeatedly press the lump because this can deepen irritation or spread infection.

Note when it appeared and whether its size, tenderness, colour, or drainage changes. If you resume shaving, use a clean sharp razor, shaving gel, and light strokes in the direction of hair growth.

Seek prompt assessment if redness spreads, pain or swelling rapidly worsens, pus collects, you develop fever or feel unwell, or arm movement becomes difficult. These features may need treatment for a skin infection or abscess.

Book an appointment if the lump persists after the skin irritation has cleared, keeps enlarging, feels hard or fixed, returns, or occurs with a breast or chest change, unexplained night sweats, or unexplained weight loss. New breast skin dimpling, nipple inversion, or bloody nipple discharge also warrants assessment.

Ask whether the bump appears to arise from the skin or a lymph node, whether infection treatment is needed, and when it should be rechecked. You can also ask whether an examination of the breast or chest, imaging, or another test would help clarify a persistent lump.