testosterone is the major male hormone. there are three different types of blood tests that can be used to measure testosterone levels. so the first step in understanding your level is to find out which test was used and the normal range for men in your age group. total testosterone is the most common test used. it measures all the testosterone in your blood. a typical range for men over 19 is 240-950 ng/dl but the results vary depending on the lab used. you can also measure free testosterone. free testosterone is a measure of the testosterone that is not bound to proteins in the blood. a typical range for men is 9-30 ng/dl. obesity affects the level of sex hormone binding proteins so your doctor may order a free testosterone level if you are obese. historically it was thought that only free testosterone was able to exert hormonal effects. we now know that testosterone bound to the protein albumin can also exert effects. bioavailable testosterone measures this level. bioavailable testosterone varies depending on the age of the man. for a man in his 20’s the normal range of bioavailable testosterone would be 83-257 ng/dl but for a man in his 60’s it would be 40-168 ng/dl. normal ranges differ depending on the laboratory used so be sure to discuss with your doctor what is the appropriate normal range for the lab where the test was done. if your testosterone level is low it is important to re-test the level to determine if a lab error or just a daily variation has occurred. the amount of testosterone varies at different times of the day so this is a blood test that needs to be repeated before making medical decisions. it is always important to make sure lab tests correlates with your symptoms. low testosterone levels in men causes decreased sexual desire erectile dysfunction and infertility. however testosterone also has other important functions. it affects behavior muscle mass and bone density. therefore a man with low testosterone can develop osteoporosis. finally in understanding testosterone levels your doctor needs to determine whether the root of the problem is a result of a problem in the testicles where testosterone is produced or if there is a problem in the part of the brain that controls the production of testosterone. measuring lh and fsh hormones produced in the pituitary of the brain will help make that distinction. once this information is available your doctor can decide how you need to be treated. testosterone replacement in the form of a patch gel or injection is usually given. but as with all medications there are cautions. testosterone can increase the size of the prostate and may cause worsening symptoms in men with benign prostatic hypertrophy and aggravate prostate cancer. so talk with your doctor to understand your test and his concerns.
my testosterone level is a 9 yet my doctor did not recommend injections. what is going on.?