What causes male infertility

What causes male infertility?

There are many potential causes of male infertility. Some conditions may impact a man’s fertility in more than one way. A definitive cause for infertility will not be found in some men. Your doctor will work with you to try to find causes for fertility that are

  • Reversible
  • Treatable
  • A threat to your health
  • Or may impact the health of your child

Potential causes of infertility can be organized into pre-testicular, intratesticular, post-testicular, and extra testicular causes.

Pre testicular

Pre-testicular conditions effect the chemical signals that tell the testicle to make testosterone and/or make sperm. These signals come from a parts of the brain called the hypothalamus and pituitary gland. Pretesticular causes of infertility include:

  • Hypothalamic disorders
  • Pituitary disorders
  • Brain tumors
  • Radiation or surgery on the brain
  • Exogenous testosterone/anabolic steroids


Extra testicular

Sometime the amount of sperm and/or the quality of the sperm can be effected by conditions unrelated to the reproductive organs or by exposures to certain substances or drugs. Extra-testicular causes of infertility include:

  • Severe illness
  • Heat (such as hot tubs or saunas)
  • Obesity
  • Medications
  • Cigarettes
  • Excessive alcohol consumption
  • Recreational drugs (e.g marijuana)
Infographic of the male body


Sperm is mixed with fluid from the prostate and seminal vesicles to form semen. The semen must make it into the vagina to reach the egg and cause a natural pregnancy. Conditions that block sperm from entering the semen, or prevent the semen from being ejaculated into the vagina can cause infertility. Post-testicular causes of infertility include:


Damage to, or poor function of, the testicle can affect how well the testicles can make sperm. Testicular causes of infertility include:

  • Torsion of the testicle
  •  Undescended testicle
  • Genetic disorders
  • Primary testicular failure
  • Scrotal trauma
  • Varicocele
  • Epididymitis/infection
  • Cancer treatments (such as radiation or chemotherapy)