The word testosterone conjures up images of all things manly.  Testosterone is actually a sex hormone that plays an important role in the male sexual development and is produced in the testes.  Hormones, in general, are chemical messengers that are transported all over the body through the blood and they regulate various things like growth, metabolism, reproduction and many other things.  In men, testosterone plays a role in developing the sexual organs, in certain characteristics like bone development, growth of hair, deep voice etc, in sperm production and in having a sex drive.  However, for the hormones to work properly there has to be a balanced equilibrium of the various hormones. 

How are testosterone levels controlled

When testosterone levels are low in the blood, the hypothalamus in the brain is stimulated to produce gonadotrophin-releasing hormone which in turn increases the production of luteinizing hormone (LH) and follicle stimulating hormone (FSH) in the pituitary gland in the brain.  This increase in LH leads to increase in secretion of testosterone in the testes which in turn leads to increased levels of testosterone in the blood.  The increase in FSH leads to an increase in sperm production.  If there is too much testosterone in the blood the reverse happens leading to an eventual decline in testosterone.  So there is a fine balance in the production of various hormones.  Sometimes however, this balance is thrown off and it can lead to higher or lower levels of testosterone.

What could affect testosterone levels

There are many things that can cause too high or too low levels of testosterone.  Some of these include having certain illnesses like liver or kidney disease, diabetes, cancer, tumors, or some issues with the pituitary gland.  Lifestyle can also affect testosterone levels like too much or no exercise, obesity, poor diet, alcoholism, smoking or stress.  Certain genetic conditions like Klinefelter syndrome, injury of the testicles, certain medications, and chemotherapy or radiation can also affect testosterone levels.  Increased age can also decrease testosterone levels. 

Effects of low testosterone

Low testosterone, also known as hypogonadism, can delay puberty and its symptoms could include low sex drive, fatigue, decrease in muscle mass, irritability, erectile dysfunction and depression. Testosterone level is usually measured with a blood test done early in the morning because the levels can vary during the day with the highest during the morning and lowest at night.  Low testosterone can directly affect fertility by causing decreased sperm production and indirectly affect fertility by reducing his sex drive and causing erectile dysfunction.  If you have low sperm count and are trying to have a baby but are having trouble conceiving, your doctor may suggest going through invitro fertilization (IVF) where the sperm is fertilized with the egg in a laboratory setting and the resulting embryo is transferred back into the woman’s uterus for implantation.

Effects of high testosterone

High levels of testosterone can cause symptoms such as aggression, high blood pressure, high sex drive, increase in hair growth, and acne.  However, abnormally high levels of testosterone can actually decrease sperm production, especially if you are using steroids or supplements.


Men with low testosterone levels could still have enough testosterone levels for sperm production because the concentration of the testosterone in the testes where sperm production occurs is much higher than in the bloodstream.  However, one needs to look at the root cause of why the levels are low or high especially if you are wanting to have a baby and are having trouble conceiving.  Other than a blood test to determine levels of various hormones, they might also do a semen analysis, ultrasound, biopsy of the testicles and genetic testing to find out what is causing the issue.  You might need to look at any underlying health conditions and lifestyle factors first to see if these could be affecting your testosterone levels and try to rectify this first.  Many people think having low testosterone levels can be fixed by taking testosterone supplements.  Taking testosterone supplements could shut off the body’s ability to make its own testosterone and sperm and could lead to infertility.  However, in most cases, the infertility caused by testosterone treatment is reversible.  So people on hormone replacement therapy or testosterone treatment have to be monitored closely by their physician.  Any form of testosterone supplementation can disrupt the normal hormonal balance required for sperm production. So men should avoid testosterone treatment if they want to have their own biological children or should consider freezing their sperm for later use. If a man has a pituitary disorder, for example, that is causing the low testosterone, then he can be treated with a pituitary hormone (hCG) that will increase his testosterone level without disrupting sperm production. When he no longer wants to have any more children and feels the low testosterone levels is affecting his sex drive, he could undergo testosterone treatment to treat his low testosterone levels.  However testosterone replacement therapy can affect each individual differently in that one might notice big changes and others might hardly notice any effect at all.  Dealing with decreased fertility could be mentally and emotionally draining.  You could try talking to your partner, a close friend or a professional or join a support group to help you cope with your particular situation.  If you have any questions about your testosterone levels or feel that you might be experiencing some of the symptoms, feel free to talk to the specialists at Xenith Advanced Fertility Centre to help you understand what you are dealing with.  Know that you are not alone in this situation and that there is always hope.