Im 25 and currently have a swollen left testicle. i have no pain but a small lump on the chord. could this be a blockage of sperm?

Get it checked. : If you have unexplained enlargement of a testicle, see your gp for a history and physical exam. An ultrasound of the testicle should be performed to rule out a testicular tumor. A small blockage of the tubes that convey sperm can cause a lump to form in the epididymis, and is called an epididymal cyst. But the testicular swelling is a much more worrisome finding, and should be evaluated promptly.