Why could you hold a stack of books on your head without pain, whereas it would hurt if someone put a small pebble between the book and your head

Chad wilson is a 21 year old male in good health. in the middle of the night. chad woke up with severe pain in the right side of the testicle and he noticed that is swollen. it is also painful when he tries to urinate. he hates to go the doctor, but he us worried that he might have testicular cancer. question 1. the possible disease and condition on each case study. 2. any examination or tests that will confirm or refute the diagnose. 3. additional steps that the patient should take. (e.g. taking medication or adopting a new health habit)