Sterility refers to the biological incapability of an individual to bear a child. It may also refer to the inability of a woman to carry pregnancy to its full term. Sterility is often caused due to biological reasons, some of which can be treated with medical intervention. Men and women have an equal share of sterility cases at 40 percent each, while the remaining 20 percent cases are caused due to the complications in both men and women.

There are certain general causes, those specific to women and those specific to men. General causes include DNA damage, diabetes, thyroid disorders, adrenal disease, toxins and smoking. Certain causes are specific to females, such as ovulation problems, tubal blockage, uterine problems, endometriosis and age related factors. Low semen quality, hormone imbalance, and testicular malformations are likely causes of infertility in men.