If you have lumps, swelling, hardness, pain or heaviness in your testicles, it could be a sign of a number of conditions. Among the more serious is testicular cancer. So, if you’re worried about any of these symptoms, a short visit to your GP practice should help you to get to the bottom of it.
https://www.testicularcancernetwork.co.uk/april-testicular-cancer-awareness-month
Cancer of the testicles is one of the less common cancers and tends to occur in men aged 15 to 49. There are a number of risk factors, which include an undescended testicle or testicles, a family history and previous testicular cancer, though all men should be vigilant and check for symptoms.
https://www.nhs.uk/conditions/testicular-cancer/