Testicular cancer is a type of cancer that develops in the testicles, the male reproductive glands responsible for producing sperm and testosterone. It is relatively rare but is the most common cancer in males aged 15 to 35. The majority of testicular cancers are germ cell tumors, which include seminomas and non-seminomas. While the exact cause is often unknown, risk factors include undescended testicles (cryptorchidism), a family history of testicular cancer, and certain genetic conditions. Common symptoms include a painless lump or swelling in the testicle, a feeling of heaviness in the scrotum, or discomfort in the lower abdomen or groin.

Testicular cancer is highly treatable, especially when detected early. Diagnosis typically involves a physical examination, ultrasound imaging, and blood tests for tumor markers. Treatment depends on the type and stage of the cancer and may include surgery (orchiectomy), radiation therapy, and chemotherapy. Regular self-examinations and prompt medical attention to any testicular changes can significantly improve the chances of successful treatment and long-term survival. Most men treated for testicular cancer can lead normal, healthy lives, including preserving fertility in many cases.