Table: What Causes Infertility in Men? - Merck Manuals Consumer Version

Health Topics & Chapters

What Causes Infertility in Men?

What Causes Infertility in Men?

Cause	Examples
Reduced sperm production
Increased temperature of the testes	Excessive heat Disorders that cause a prolonged fever
Hormonal disorders	Adrenal gland disorders Overview of the Adrenal Glands The body has two adrenal glands, one near the top of each kidney. They are endocrine glands, which secrete hormones into the bloodstream. Each adrenal gland has two parts. Medulla: The inner... read more (this gland produces testosterone and other hormones) Hyperprolactinemia (high levels of prolactin, a hormone that stimulates milk production) Hypogonadism Male Hypogonadism in Children Hypogonadism is decreased production of testosterone, sperm, or both in males. Hypogonadism occurs when there is a problem in the testes or a problem in the pituitary gland or the hypothalamus... read more (low levels of testosterone and/or impaired production of sperm), sometimes related to obesity Hypothalamic disorders (the hypothalamus is the part of the brain that controls the pituitary gland, which controls testosterone production) Hypothyroidism Hypothyroidism Hypothyroidism is underactivity of the thyroid gland that leads to inadequate production of thyroid hormones and a slowing of vital body functions. Facial expressions become dull, the voice... read more Pituitary gland disorders Overview of the Pituitary Gland The pituitary is a pea-sized gland that is housed within a bony structure (sella turcica) at the base of the brain. The sella turcica protects the pituitary but allows very little room for expansion... read more
Genetic disorders	Cystic fibrosis Cystic Fibrosis (CF) Cystic fibrosis is a hereditary disease that causes certain glands to produce abnormally thick secretions, resulting in tissue and organ damage, especially in the lungs and the digestive tract... read more Klinefelter syndrome Klinefelter Syndrome Klinefelter syndrome is a sex chromosome abnormality in which boys are born with two X chromosomes plus one Y (XXY). Klinefelter syndrome occurs when a boy has one extra X chromosome. Boys may... read more Other disorders that cause an abnormality in the sex chromosomes
Disorders of the testes	Infections Injury to the testes Mumps that affects the testes (mumps orchitis Mumps is a contagious viral infection that causes painful enlargement of the salivary glands. The infection may also affect the testes, brain, and pancreas, especially in adults. Mumps is caused... read more ) Shrinking of the testes (as can occur when excess alcohol is regularly consumed) Tumors in the testes Undescended testes Undescended Testes and Retractile Testes Undescended testes (cryptorchidism) are testes that remain in the abdomen or the groin instead of descending into the scrotum. Retractile testes (hypermobile testes) have descended into the... read more (testes that remain in the abdomen rather than move to the scrotum) Varicose veins in the testes (varicocele Scrotal Swelling Swelling of the scrotum (the sac that surrounds and protects the testes) on one or both sides may be a symptom of a urinary tract disorder. Swelling can be small and detectable only by carefully... read more )
Drugs	Alcohol, when consumed in large amounts Anabolic steroids Androgens (male hormones such as testosterone) Antiandrogens (drugs that counteract the effects of androgens, such as bicalutamide, cyproterone, and flutamide) Antimalarial drugs Aspirin when taken for a long time Caffeine when consumed in excessive amounts (possibly) Chlorambucil (a chemotherapy drug) Cimetidine (used to treat stomach ulcers) Colchicine (used to treat gout) Corticosteroids taken by mouth (such as prednisone) Cotrimoxazole (an antibiotic) Cyclophosphamide (a chemotherapy drug) Drugs used to treat malaria Estrogens taken to treat prostate cancer Gonadotropin-releasing hormone (GnRH) agonists (hormonal drugs used to treat prostate cancer Treatment The risk of prostate cancer increases as men age. Symptoms, such as difficulty urinating, a need to urinate frequently and urgently, and blood in the urine, usually occur only after the cancer... read more , fibroids A fibroid is a noncancerous tumor composed of muscle and fibrous tissue. It is located in the uterus. Fibroids can cause pain, abnormal vaginal bleeding, constipation, repeated miscarriages... read more , endometriosis In endometriosis, patches of endometrial tissue—normally occurring only in the lining of the uterus (endometrium)—appear outside the uterus. Why endometrial tissue appears outside the uterus... read more , and other disorders) Ketoconazole Marijuana Medroxyprogesterone (a synthetic female hormone) Methotrexate (a drug that suppresses the immune system) Monoamine oxidase inhibitors (MAOIs—a type of antidepressant) Nitrofurantoin (an antibiotic) Opioids (narcotics) Spironolactone (a diuretic) Sulfasalazine (an antibiotic sometimes used to treat inflammatory bowel disease Overview of Inflammatory Bowel Disease (IBD) In inflammatory bowel diseases, the intestine (bowel) becomes inflamed, often causing recurring abdominal pain and diarrhea. The two primary types of inflammatory bowel disease (IBD) are Crohn... read more )
Exposure to industrial or environmental toxins	Heavy metals, such as lead Pesticides (which can have effects similar to those of female hormones or decrease the effects of male hormones) Phthalates (chemicals used to make plastics more flexible) Polychlorinated biphenyl compounds (PCBs)
Absence of sperm in semen
Disruption of the sperm’s passage out of the body	Missing epididymides (which provide the space and environment for sperm to mature), usually in men with cystic fibrosis Cystic Fibrosis (CF) Cystic fibrosis is a hereditary disease that causes certain glands to produce abnormally thick secretions, resulting in tissue and organ damage, especially in the lungs and the digestive tract... read more Blocked or missing vasa deferentia (tubes from the epididymides to the ejaculatory ducts), usually in men with cystic fibrosis Missing seminal vesicles (which provide nourishment for sperm) Blockage of both ejaculatory ducts
Retrograde ejaculation Retrograde Ejaculation Retrograde ejaculation is a condition in which semen is ejaculated backward into the bladder rather than out through the penis. (See also Overview of Sexual Dysfunction in Men.) In retrograde... read more (semen travels back into the bladder rather than out of the penis)	Diabetes mellitus Nervous system dysfunction Pelvic surgery, such as prostate removal Removal of lymph nodes in the area behind the abdomen (as may be done to treat Hodgkin lymphoma Treatment Hodgkin lymphoma is a type of lymphoma distinguished by the presence of a particular kind of cancer cell called a Reed-Sternberg cell. The cause is unknown. Lymph nodes enlarge but are usually... read more )
Erectile dysfunction Problems With Ovulation The ovaries do not release an egg each month, as usually occurs during a menstrual cycle. Ovulation problems can result from dysfunction of the part of the brain and the glands that control... read more (the inability to attain or maintain an erection sufficient for sexual intercourse)
—	Blood vessel disorders Diabetes mellitus Brain and nerve (neurologic) disorders, such as Alzheimer or Parkinson disease, multiple sclerosis, stroke, and nerve damage due to prostate surgery Psychologic problems, such as performance anxiety or depression Certain drugs, such as some antidepressants, certain hormonal drugs, and drugs used to treat high blood pressure (including beta-blockers) Recreational drugs (such as cocaine, heroin, and amphetamines) Unknown causes (idiopathic)