"No, underwear choice is not a primary cause of blood pooling in the scrotum, also known as a varicocele. Varicoceles are caused by issues with the valves in the veins of the scrotum, which can lead to sluggish blood flow and pooling. However, some people with varicoceles may find that certain types of underwear are more comfortable than others.
For people with varicoceles, wearing tight or constrictive underwear can sometimes make discomfort worse. In contrast, wearing looser, more breathable underwear or a jockstrap can sometimes help provide support and reduce symptoms. Other ways to ease the discomfort of a varicocele include:
Lying on your back to help the varicocele drain
Taking pain killers like acetaminophen or ibuprofen "
From Google AI.