From the Guidelines
Testosterone levels should be checked in men with symptoms of low testosterone, such as decreased libido, erectile dysfunction, fatigue, reduced muscle mass, increased body fat, or mood changes, as well as in those with a history of unexplained anemia, bone density loss, diabetes, exposure to chemotherapy, HIV/AIDS, chronic narcotic use, male infertility, pituitary dysfunction, and chronic corticosteroid use, according to the most recent guidelines 1.
Key Considerations
- Testing is typically recommended in the morning (between 8-10 AM) when levels are naturally highest, as testosterone follows a daily rhythm.
- The diagnosis of low testosterone should be made only after two total testosterone measurements are taken on separate occasions with both conducted in an early morning fashion 1.
- Men should be fasting for accurate results, and the standard test measures total testosterone, though free testosterone testing may be needed in some cases.
- If initial results show low levels, a repeat test is usually recommended to confirm findings before considering treatment.
Specific Situations Warranting Testing
- Unexplained anemia
- Osteoporosis
- HIV-associated weight loss
- Pituitary disorders
- Chronic opioid use
- Certain genetic conditions like Klinefelter syndrome
Monitoring and Treatment
- Testing should be done before starting testosterone replacement therapy and periodically during treatment to monitor levels and adjust dosing.
- This monitoring helps ensure testosterone levels reach the therapeutic range (typically 350-1000 ng/dL) while minimizing potential side effects like elevated red blood cell counts or prostate issues 1.
Clinical Evaluation
- Clinicians should make note of any patient-reported symptoms associated with low testosterone and conduct a targeted physical exam to examine patients for signs that are associated with low testosterone 1.
From the Research
When to Check Testosterone Level
- Testosterone deficiency can be suspected in men with symptoms such as decreased libido, erectile dysfunction, decreased physical stamina and strength, depressed mood, fatigue, increased visceral adiposity, sleep disturbance, and/or poor concentration and memory 2, 3.
- Investigation of testosterone deficiency should be undertaken in men with symptoms of reduced libido, erectile dysfunction, depression, fatigue, poor concentration, and poor memory 3.
- Total and free testosterone are the most frequently used tests to evaluate testosterone levels, and serum concentrations of luteinizing hormone can aid in determining primary versus secondary testosterone deficiency 3.
- Hypogonadism or testosterone deficiency in adult men is defined by low levels of serum testosterone accompanied by characteristic symptoms and/or signs, and can be found in men with idiopathic, metabolic or iatrogenic conditions that result in testosterone deficiency 4.
- Age-related hypogonadism is due to a combination of primary hypogonadism (testicular failure) and secondary hypogonadism (hypothalamic-pituitary axis failure), and testosterone levels can decline with age 5.
- Pituitary dysfunction should be considered in men presenting with signs and symptoms of hypogonadism, and evaluation of other pituitary hormone functions as well as pituitary magnetic resonance imaging may be necessary 6.
Key Considerations
- Testosterone deficiency is estimated to affect more than one-third of men 45 years and older 2.
- No single sign or symptom defines testosterone deficiency, and a combination of clinical evaluation and laboratory tests is necessary for diagnosis 2, 3.
- Testosterone therapy can be considered a safe and effective treatment for testosterone deficiency, but monitoring during therapy is mandatory 3.