Testosterone is primarily produced by the testes, with a small amount produced by the adrenal glands. The majority of circulating testoerone is bound to proteins including albumin and sex hormone binding globulin (SHBG), however the active testosterone, free testosterone is not attached to proteins. While commonly regarded as the primary male sex hormone, testosterone is important for bone density, libido, body fat distribution, and supporting muscle mass across all sexes.
In men, LH stimulates Leydig cells in the testicles to produce testosterone. Low levels of LH may indicate a problem with the pituitary or hypothalamus and can lead to low testosterone levels. Normal sperm production requires a high level of testosterone levels in the testicles, so LH can indirectly be a good indicator of fertility as well.
Estradiol is one of the main types of estrogen, and while it is the primary female hormone, it is found in all sexes. The estrogen present in men is mainly converted from testosterone by an enzyme called aromatase, found commonly in belly fat. As men age, their estradiol levels naturally increase but can be elevated above healthy levels due to a number of other factors. Estradiol plays a role in bone maintenance, brain function, as well as male fertility by helping with fluid balance in the testicles. High Estrogen can result in weight gain, increased chest and belly fat, hot flashes and night sweats.
Sex Hormone Binding Globulin (SHBG) is made by your liver. SHBG transports and controls how much of these hormones are available for your body to use. SHBG levels that are too high or too low can be a sign that there are too much or too little hormones available for your body to use. Abnormal levels may indicate liver disease, diabetes, or abnormal thyroid function.
The PSA test is a blood test used primarily to screen for prostate cancer and can provide an index of prostate health. The test measures the amount of prostate-specific antigen (PSA) in your blood. PSA is a protein produced by both cancerous and noncancerous tissue in the prostate, a small gland that sits below the bladder in males. PSA is mostly found in semen, which also is produced in the prostate. Small amounts of PSA ordinarily circulate in the blood. High levels of PSA that may indicate the presence of prostate cancer. However, many other conditions, such as an enlarged or inflamed prostate, also can increase PSA levels.
