I am a married man, age 40. About 2 days ago I started feeling mild discomfort in my left testicle. I noticed the following morning that the testicle was swollen and very tender to the touch, in particular on the rear side. (Not chronic pain just enough to annoy me) I did a self exam and do not feel any mass/tumor or veins, just that the left testicle is enlarged and painful to the touch. I applied ice and the swelling went down. This morning I woke up without any pain but the testicle was again swollen. As the day progressed the mild pain has returned but again, only when the area is touched. Today I took an anti-inflammatory medication I take for a back problem and again, the swelling has subsided. The issue seems to be improving but is still continuing.

I should add that I did receive a light blow to the groin when playing with my children the other day.

I am mildly sexually active only with my wife (about 2 times a month) and I do masturbate frequently at times (sometimes 2 times per day).

any thoughts on what this may be?