What is the reason for the pain that radiates from the testicles to a line on the left side of the waist?

Patient's question:

Left testicle and left waist connected by a line in pain~~~~Pain when sitting and standing, only lying on the right side! Previously sat on a stone bench for 2 hours~~and then the problem appeared! No problem with the right waist
Age: 20
I have a habit of masturbation (also for 6 years), and ointments and haven't worked~~There's also a small issue with urination (urine flow improved after taking traditional Chinese medicine)! A little pain in the waist and testicle makes walking and riding a bicycle a problem!
Doctor, what is this disease? Is it serious?

Doctor's answer:

There are many causes that can trigger testicular pain, including orchitis, epididymitis, varicocele, hydrocele, chronic prostatitis, seminal vesiculitis, herniated disc, and so on. These conditions can all cause testicular pain. If you haven't engaged in heavy physical labor and are experiencing fatigue and testicular swelling or pain, it is recommended to visit a urology department for examination to rule out prostatitis. The presence of pain or a sense of heaviness suggests that you should go to a regular hospital's urology department for relevant tests to identify the cause and receive targeted treatment.