Varicocele, an enlargement of the veins within the scrotum, it is more common in younger males, ages 15-25.
Because a varicocele rarely produces symptoms, it is not uncommon for a man not to be aware that he has one unless it causes problems with fertility or is noticed during a routine physical exam. When symptoms do occur, they tend to be felt as a dull ache or feeling of heaviness in the testicle, which gets worse during the day, particularly in hot weather or after physical exertion. The dilated veins in the scrotum can often be felt or seen, and the testicle is smaller on the varicocele side
Treatment is generally necessary only for infertility, or if the varicocele causes persistent pain or discomfort (even after attempting non-surgical approaches such as anti-inflammatory medications and wearing snug underwear or a jock strap) or significant testicular atrophy.
So follow doctor advice and check with him if the pain is bearable or if it is persistant and disturbing beside treatment and pain killers.