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 relatively rare, affecting about 1 in 250 men during their lifetime. The exact cause is not known, but certain risk factors, such as a family history of the disease or undescended testicles, can increase the likelihood of developing it. Symptoms of testicular cancer may include a lump or swelling in one testicle, discomfort, or changes in size. Early detection is crucial for effective treatment, which may involve surgery, radiation, or chemotherapy. Regular self-examinations can help in identifying any unusual changes early on.