Is armpit pain a sign of cancer?

　　In general, whether armpit pain is related to cancer should be determined based on the specific characteristics of the pain, accompanying symptoms, and relevant examination results. If discomfort occurs, it is recommended to seek medical attention promptly. The detailed analysis is as follows:

　　If armpit pain is accompanied by a hard, poorly defined, immobile lump that gradually increases in size over a short period, and if additional symptoms such as skin ulceration in the armpit, nipple discharge, or unexplained weight loss occur, there should be concern for possible cancer-related conditions, such as axillary lymph node metastasis from breast cancer or lymphoma. A definitive diagnosis would require further evaluation, including pathological examination.

　　If the armpit pain is intermittent dull ache or distending pain, accompanied by local redness, swelling, and warmth, or if the pain is associated with the menstrual cycle, intense physical activity, or local friction, it is more likely caused by benign conditions—such as axillary lymphadenitis, infected sebaceous cysts, or muscle strain. Symptoms often improve with anti-inflammatory treatment and rest.

　　In daily life, one should monitor the armpit area for lumps or unusual skin changes and avoid repeatedly pressing or irritating the painful area. If pain persists for more than one week without improvement, or if lumps, abnormal discharge, or other concerning signs appear, prompt medical evaluation is necessary. Diagnostic tools such as ultrasound and complete blood count can help identify the underlying cause and prevent delayed treatment.