Oligospermia refers to the condition in which the semen of a male has low concentration of sperms. It is a common cause of male infertility. Normal sperm count is between 20 million sperms per millimeter to 120 million sperms per millimeter of the semen. Less than 20 million sperms per millimeter of semen is termed as oligospermia. It needs to be noted that the concentration of sperms can fluctuate and the condition itself can be temporary or permanent.

There are certain conditions in which the male testes produce poor quality semen. These conditions include age, genetic conditions, abnormal set of chromosomes, trauma, malaria, varicocele, Neoplasm and Cryptorchidism. Treatment methods include use of antibiotics if there is any infection, surgical correction in case of varicocele, vas deferens obstruction or hydrocele. Men with pituitary hypogonadism can opt for using FSH to seek improvement in sperm concentration.