Understanding Your TestosteroneUnderstanding Your Testosterone or Hormone levels decline as a part of normal aging, and are the cause of several physiological changes. Low testosterone levels in men are associated with a variety of symptoms including reduced motivation, erectile dysfunction, loss of libido, fatigue, increased cholesterol levels, memory loss, reduced muscle mass, and thyroid dysfunction. Because these symptoms are common, physicians will often include hormone levels as part of routine blood work. Read on to learn about the different types of testosterone Injections and understand how to interpret your testosterone levels.
The Different Types of TestosteroneUnderstanding Your Testosterone, because there are two main types of testosterone circulating in the body: free testosterone, testosterone bound to albumin, and testosterone bound to sex hormone-binding globulin (SHBG). Approximately 60–70% of circulating testosterone is tightly bound to SHBG and so is “inactive” because it cannot bind to its cellular receptor to elicit physiological effects. The most physiologically relevant form of testosterone is “bioavailable.” Both free testosterone (free T) and albumin-bound testosterone are considered bioavailable, which means that they are free to activate the androgen receptor and elicit biological effects. Free T and albumin-bound testosterone account for ~2% and 30–40% of the total amount of circulating testosterone, respectively .
Testosterone Assay ResultsA physician might measure Understanding Your Testosterone levels in several different groups of patients:
- Men experiencing fertility problems
- Men with erectile dysfunction or a low sex drive
- Boys undergoing premature puberty
- Women developing typically male features, such as excessive facial and body hair or a deepening of the voice
- Women with irregular menstruation
- Patients with prostate cancer receiving androgen-blocking medications
- Men with osteoporosis
|Total testosterone measurable range||250 to 827 ng/dL||Bioavailable testosterone normal range||Age 18–69 years||110.0 to 575.0 ng/dL||Age >|
|Free testosterone normal range|
|Age 18–69 years||46.0 to 224.0 pg/mL|
|Age >69 years||
6.0 to 73.0 pg/mL
What do Low Testosterone Levels Mean?If your testosterone assay results are low, you do not need to worry. It could be a result of normal aging, due to a medication you are taking, or it could be secondary to the altered production of other hormones such as the luteinizing hormone or follicle-stimulating hormone. Your physician will discuss the results with you, try to identify the reason for the low levels, and prescribe any necessary medications. References
- Jarari, N., et al., A review on prescribing patterns of antihypertensive drugs. Clin Hypertens, 2015. 22: p. 7.