### Human:\nwhat tests are done to determine the cause of male infertility?\n\n### Assistant: identifying the cause of a man's infertility is as much an art as a science. “the first step is an evaluation by a physician specializing in male infertility ” says stephen shaban md a urologist specializing in male reproductive medicine and microsurgery in raleigh north carolina. experts differ in their approach but here are some of the tests you can expect: sperm and semen analysis. they provide a private room (and magazines). you provide a fresh sample of semen. experts then assess your sperm count their shape movement and other variables. “generally a higher number of normal-shaped sperm means higher fertility ” says shaban. but exceptions are common. many men with low sperm counts or abnormal semen are still fertile. and about 15% of infertile men have normal semen and plenty of normal sperm. surprisingly the complete absence of sperm in the semen (a condition known as azoospermia) can be a good thing. lawrence ross md president of the american urological association says it might suggest a blockage in the “plumbing” that can be corrected with surgery. physical examination. a thorough physical exam can detect varicocele and give clues to hormone problems. this should ideally be performed by a urologist. hormone evaluation. testosterone and multiple hormones made in the brain control sperm production. however hormones are not the main problem in 97% of infertile men. testicular biopsy. this is done for men with very low or no sperm in their semen. a needle biopsy of the testicle can show whether a man is making healthy sperm. if abundant good sperm are found in the testicle there's likely a blockage somewhere. genetic testing. genetic tests can identify specific obstacles to fertility and problems with sperm. experts differ as to when genetic tests should be done.