I have been experiencing pain in my left testicle. I can't recall when it began but it has been so for a year or so. The pain is more pronounced during physical activities. It is also there when mild pressure is applied on the testicle during sexual activity or while wearing tight clothing. Without application of pressure, the pain is almost negligible and not noticeable. I would like to know what could be the cause of it so that I can acquire information about it before consulting a doctor.