Difference Between Impotence and Sterility

Children are the most important thing in our lives. However, there are many couples whom only dream of having kids but are unable to have one. There may be many reasons for this. While looking into these possibilities, the terms impotence and sterility come into the picture. While both may lead to not having children, it is important to understand that they are not the same.


Impotence is defined medically as the inability to get an erection. There are many reasons for impotence ranging from medical to psychological. The proper medical term is erectile dysfunction. Erection is achieved when blood enters the penis and the veins are constricted to limit the outflow. Erection is usually initiated with sexual arousal. Brain sends signals to the nerves in the penis which dilate supplying arteries and constricts draining veins.

Causes for impotence can be broadly divided into physical and psychological causes. Physical causes are diabetes, cardiovascular diseases, neurological (nerve damage during prostatectomy), hormonal inadequacies (hypogonadism), arsenic poisoning, renal failure, cavernousal diseases and drugs. Psychological erectile dysfunction is an actual failure of thought and not a physical abnormality. Performance anxiety (anxiety due to uncertainness of adequate sexual performance), depression, phobias and other negative thoughts are among common causes of psychological impotence.

History is very important in diagnosing erectile dysfunction. Having an erection when asleep is a clear indicator of active physical mechanisms. This suggests psychological impotence. Nerve conduction tests, bulbocavernous reflex, penile biothesiometry, and magnetic resonance angiography are investigations done to detect a physical cause for impotence.

Common methods of treatment are 5 phosphodiesterase inhibitors, penile prosthesis, penis pump and alternative medical treatment plans.


Sterility is a medical diagnosis. It means the inability to have children using conventional means. A couple may be considered to be infertile if they fail to conceive for two years despite regular intercourse with proper penetration and internal ejaculation without the use of a contraceptive method. This is the World Health Organization’s definition of sterility. Sterility may be intentional, and it is a method of family planning especially if the family is complete. Unintentional causes of infertility are numerous.

Cause may be common, male specific and female specific. Common causes are DNA damage, genetic mutations leading to miscarriages, low pituitary hormones, low prolactin levels, and environmental factors. Female specific causes are ovulation issues (polycystic ovarian syndrome), destruction of released ova (endometriosis, pelvic inflammatory disease), tubal block, abnormal architecture of the uterus and advanced maternal age. Male specific causes are oligospermia and azoospermia. This may be due to drugs, surgery, irradiation, toxins and physiologically unfavorable conditions for spermatogenesis.

Genetic testing, karyotyping, hormonal assays, toxicology screen, ultrasound abdomen, blood sugar levels, and sperm count are among common investigations done to assess subfertility. Treatment depends upon the cause. Usually, treating the underlying cause restores fertility and sometimes couples may need assistive reproduction technique like ovulation induction, sperm preparation, intra-uterine insemination, and in vitro fertilization.

What is the difference between Impotence and Sterility?

• Impotence is a cause for subfertility because it interferes with natural conception while sterility is the actual inability to conceive naturally.

• Impotence suggests an isolated inability to achieve an erection while sterility is a broad term covering a whole list of causes.

• Once impotence is treated a coupe should be able to conceive if impotence was the only abnormality.

• Impotence does not suggest a poor sperm count while sterility may be due to a low sperm count.

• Sterility required assistive reproduction techniques like IUI and IVF while a couple would not need these fancy methods once impotence is treated.