Testicular cancer warning signs include a lump or swelling in the testicle, often painless and detected during self-examination or by a doctor. Pain, heaviness, or discomfort in the testicle or scrotum may also occur, though some men experience no pain at all. Sudden fluid collection in the scrotum (hydrocele) can indicate an underlying problem and should be evaluated. Breast tenderness or enlargement (gynecomastia) may develop due to hormone changes from certain testicular cancers. Finally, back pain or abdominal pain can occur if cancer has spread to lymph nodes. Early detection significantly improves treatment outcomes, so any persistent changes warrant prompt medical evaluation. A doctor can distinguish between benign conditions like cysts or infections and actual cancer through physical examination and imaging. Most testicular lumps are not cancerous, but only a healthcare provider can make an accurate diagnosis. Men should perform regular self-exams by gently rolling each testicle between thumb and fingers to become familiar with normal texture and size. Any new lumps, changes in size or shape, or symptoms lasting more than two weeks should be reported to a doctor immediately.