Testosterone: Key Roles, Normal Levels, and Health Impacts

What is Testosterone?

Testosterone is a crucial hormone produced primarily in the testicles in men and the ovaries in women, with smaller amounts produced by the adrenal glands.

It is the most significant androgen in the body and is responsible for developing male physical characteristics, such as facial hair, deepening of the voice, and increased muscle mass. However, testosterone also has essential functions in women, contributing to muscle strength, bone density, and sexual desire.

Key Functions of Testosterone

• Sexual Development: During fetal development, testosterone helps form male reproductive organs. In adolescence, it drives the development of secondary sexual characteristics such as a deeper voice and increased body hair.
• Muscle and Bone Health: Testosterone supports muscle mass and bone density, helping maintain physical strength and reducing the risk of fractures as individuals age.
• Cognitive and Emotional Well-being: This hormone influences mood, energy levels, and cognitive functions like memory and concentration. Balanced testosterone levels contribute to a sense of well-being and vitality in both men and women.

The production of testosterone is regulated by the hypothalamus and pituitary gland, which send signals to the gonads to produce the appropriate amount of hormone. This process ensures that the body has enough testosterone to perform its various functions but not so much that it leads to adverse effects.

Diagnosis of Testosterone

When evaluating testosterone levels, it's crucial to understand the various methods used for testing, as well as the significance of the results. Proper diagnosis relies on selecting the appropriate test and interpreting the results within the context of individual health factors.

Types of Testosterone Tests

• Total Testosterone: This test measures the total amount of testosterone in the blood, including both testosterone that is bound to proteins (which cannot be used by the body) and free testosterone (which is available for use). This is the most common test for assessing testosterone levels.
• Free Testosterone: Free testosterone is the unbound form of the hormone that is readily available for use by the body’s tissues. Measuring free testosterone can provide more detailed information, especially if total testosterone levels are borderline or inconsistent with symptoms.
• Bioavailable Testosterone: This test measures both free testosterone and testosterone that is loosely bound to albumin. It gives a clearer picture of the testosterone available to the body's tissues compared to the total testosterone test.

Importance of Test Timing

UPMC Health Beat reports that testosterone levels peak in the morning and are lowest in the evening, so doctors typically schedule blood tests between 7 and 10 a.m. This timing helps ensure that the results accurately reflect your typical testosterone levels.

Testosterone Levels by Age Group

Normal testosterone levels can vary significantly depending on age, gender, and even the time of day when the test is taken. Recognizing these variations is crucial for accurately assessing thyroid function and understanding what your test results mean for your health.

Here are the normal levels taken from Labcorp:

Males

• Newborns: 75−400 ng/dL
• 1 to 7 months: 60−400 ng/dL, then stabilizes to <10 ng/dL by seven months
• 1 to 10 years: <10 ng/dL
• Adolescents (10 to 17 years): 100−970 ng/dL (varies by Tanner stage)
• Adults (>18 years): 264−916 ng/dL

Females

• Newborns: 20−64 ng/dL
• 1 to 7 months: <10 ng/dL
• 1 to 9 years: <10 ng/dL
• Adolescents (9 to 18 years): 7−38 ng/dL (varies by Tanner stage)
• Adults: Premenopausal 10−55 ng/dL, postmenopausal 7−40 ng/dL

Note: Normal ranges can vary slightly depending on age, gender, timing, laboratory, and the methods used for testing. It’s essential to discuss your specific results with your healthcare provider to understand what they mean in the context of your overall health.

For those seeking to understand their testosterone levels more clearly, consider using the Docus Lab Test Interpretation Tool for personalized insights and recommendations based on your results.

Abnormal Testosterone Levels

Abnormal testosterone levels, whether too high or too low, can significantly impact health. Understanding the causes and symptoms of these imbalances is crucial for early detection and effective management.

High Testosterone Levels

High testosterone levels, or hyperandrogenism, can be caused by various conditions and may lead to several noticeable symptoms.

• Polycystic Ovary Syndrome (PCOS): This common hormonal disorder in women leads to excess androgen production, including testosterone.
• Adrenal or Testicular Tumors: These tumors can produce large amounts of testosterone, leading to an imbalance.
• Steroid Use: The misuse of anabolic steroids, often for bodybuilding or athletic performance, artificially raises testosterone levels in the body.

• In Males: Men with high testosterone levels may experience increased aggression, acne, and excessive body hair. There may also be a reduction in sperm count, potentially leading to fertility issues.
• In Females: Women with elevated testosterone may develop male-pattern baldness, hirsutism (excessive facial and body hair), and irregular menstrual cycles. Over time, these symptoms can significantly affect the quality of life and reproductive health.

Low Testosterone Levels

Low testosterone levels, or hypogonadism, are more commonly discussed due to their impact on aging men, but they can affect individuals of any gender.

• Aging: As men age, their testosterone levels naturally decrease. This decline is gradual but can lead to noticeable symptoms over time.
• Hypogonadism: This condition, in which the testes or ovaries produce insufficient testosterone, can be congenital or acquired later in life.
• Chronic Diseases: Conditions like diabetes, obesity, and chronic kidney disease can reduce testosterone levels. Additionally, long-term use of certain medications, such as opioids or corticosteroids, can suppress testosterone production.

• In Males: Symptoms of low testosterone in men include decreased muscle mass and strength, increased body fat, low libido, and erectile dysfunction. Men may also experience mood changes such as depression and irritability, along with cognitive issues like poor concentration and memory loss.
• In Females: Women with low testosterone might notice reduced bone density, decreased libido, and muscle weakness. Emotional symptoms such as mood swings and depression are also common, particularly as testosterone levels decline with age.

Managing Abnormal Testosterone Levels

Managing abnormal testosterone levels is essential for maintaining overall health and preventing long-term complications.

Treatment Options for Low Testosterone

• Testosterone Replacement Therapy (TRT): TRT is commonly prescribed for men with hypogonadism to restore normal testosterone levels. This therapy can be administered through injections, patches, gels, or tablets, depending on the individual’s needs and preferences.
• Lifestyle Changes: Making improvements to diet, exercise, and sleep can help boost natural testosterone production. Weight loss, in particular, has been shown to increase testosterone levels in overweight men. It's also important to avoid testosterone-killing foods that can negatively impact hormone levels.
• Medications: In some cases, medications may be prescribed to stimulate testosterone production or address underlying conditions contributing to low testosterone levels.

Treatment Options for High Testosterone

• Medication: Anti-androgens can help reduce high testosterone levels, particularly in women with PCOS or other conditions causing androgen excess.
• Surgery: If high testosterone is caused by a tumor in the adrenal glands or gonads, surgical removal of the tumor may be necessary to restore hormone balance.
• Lifestyle Adjustments: Reducing stress, improving diet, and avoiding anabolic steroids can help manage testosterone levels and prevent further complications.

Regular monitoring of testosterone levels and following your healthcare provider’s recommendations are crucial for effectively managing these conditions and ensuring long-term health.

Note: Always consult with a healthcare provider for personalized medical advice based on your specific condition and health needs.

Additional Diagnostic Tests

If your testosterone levels are abnormal, your doctor may recommend additional tests to gain a more comprehensive understanding of your hormonal health.

• LH and FSH Tests: These tests measure luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are crucial for regulating testosterone production. Abnormal levels can indicate issues with the pituitary gland or hypothalamus.
• Thyroid Function Tests: Thyroid hormones can influence testosterone levels, so assessing thyroid function may be necessary to rule out thyroid-related issues.
• Imaging Tests: Ultrasounds or MRI scans can detect abnormalities in the adrenal glands or gonads, such as tumors, that might be affecting testosterone production.
• Genetic Tests: In some cases, genetic testing might be recommended to diagnose conditions like Klinefelter syndrome, which can cause low testosterone levels.

These additional tests provide a more detailed picture of your hormonal health and help your doctor determine the most appropriate treatment plan.