Causes can be:
Sexual in nature
Problems with the ejaculation
A possible blockage in the epididymis or the ejaculatory ducts
Absense of the fluid part of the semen
A misplaced urinary opening, also known as the "hypospadias"
Anti-sperm antibodies.
Cystic fibrosis - men with this disease may not have a vasa deferentia or it may be blocked.
Health and Lifestyle Causes:
Emotional stress
Deficiencies in Vitamin C, Selenium, zinc or folate
Obesity
Cancer and the treatment for this disease
Alcohol and drugs
Severe injury or having major surgery to the male reproductive organ
Other diseases that can contribute to male infertility are:
Anemia
Diabetes
Cushing's syndrome
Having a heart attack
HIV/AIDS
Kidney or Liver failure
Age:
Just like in women there is a decline in fertility with men after age 35. Men however, have a more gradual decline in fertility than women do.
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