How do varicoceles damage sperm and decrease semen quality?
There are many theories. The most commonly accepted theory is that the varicocele raises the scrotal temperature. This has been shown in scientific studies. The average scrotal temperature is approximately 94 degrees F but it is higher in men with varicoceles. We know that other causes of increased intrascrotal temperature, such as hot tub use and excessive laptop use, are associated with decreased semen quality. This also explains why a man who has a varicocele on the left side only can have decreased semen quality. Varicoceles have also been associated with DNA damage and increased reactive oxygen species (free radicals) in sperm and semen, respectively.
