Testicular cancer is a type of cancer that occurs in the testicles, which are the male reproductive organs responsible for producing sperm and hormones. It is most commonly diagnosed in young and middle-aged men, typically between the ages of 15 and 35. The exact cause of testicular cancer is not known, but certain risk factors, such as a family history of the disease or an undescended testicle, can increase the likelihood of developing it. Symptoms of testicular cancer may include a lump or swelling in one of the testicles, discomfort or pain in the scrotum, and changes in the size or shape of the testicles. Early detection is crucial for effective treatment, which may involve surgery, radiation therapy, or chemotherapy. Regular self-examinations can help men identify any unusual changes and seek medical advice promptly.