Low Testosterone Overview

Low testosterone in males goes by several different names including hypogonadism, testosterone deficiency, andropause, low T, and testicular hypofunction.  Testosterone is the main sex hormone in males and gives them muscle mass, deep voices, and male body and facial hair patterns.  As men get older, testosterone gradually decreases around 1% per year starting around age 30.  Low testosterone levels can increase your risk for other medical conditions including heart disease and osteoporosis (weak bones). 

 

The decrease in testosterone and onset of symptoms is subtle in men and often not initially identified as the cause of many common issues.  Not all men will experience the same symptoms, but common symptoms of low testosterone include:

• Erectile dysfunction

• Low sex drive

• Sleep disturbances

• Loss of muscle mass or strength

• Increased body fat

• Fatigue

• Difficulty concentrating

• Mood swings

• Lack of motivation

• Depression

• Loss of body hair

 

Approximately 15 million men have low testosterone levels, but only 5-10% seek treatment, often because men do not realize the condition is correctable.  If you are experiencing symptoms of low testosterone that negatively impacts your daily life, treatment can help.  The first step is a proper lab evaluation to identify if low testosterone is the cause and evaluate for underlying conditions that could be contributing.  Treatment of low testosterone is customized for each patient in order to meet their unique needs and safely restore testosterone to improve their quality of life.  Benefits of testosterone replacement include:

• Improved mood and motivation

• Better sleep

• Increase in lean muscle mass

• Improved athletic performance

• Weight loss

• Improved sex drive

• Improved erections

• Increased insulin sensitivity

• Increased metabolism

• Decreased recovery times

 

Laboratory Workup for Low Testosterone

Lab workup for low testosterone includes evaluating the levels of both total and free testosterone.  Total testosterone indicates the total amount of testosterone in our body, but does not represent the amount available for use in our tissues.  Free testosterone is the amount of testosterone freely circulating in our body and available for use.  Free testosterone is always lower than total testosterone because the majority of testosterone in our body is bound to proteins and not "free" or available for use.  It is important to evaluate both levels in order to accurately identify the cause of your symptoms.

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Low testosterone has several different causes, but one of the leading causes is a decrease in testosterone production from the testicles.  Several other hormones and proteins can contribute to low testosterone and include dehydroepiandrosterone (DHEA), sex hormone binding globulin (SHBG), luteinizing hormone (LH), follicle stimulating hormone (FSH), and estradiol.

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Dehydroepiandrosterone (DHEA)

DHEA is a steroid hormone made in the body that turns into testosterone.  Starting at the age of 30 your DHEA level can begin to decline leading to low testosterone levels.

 

Sex Hormone Binding Globulin (SHGB)

SHGB is a protein in our body that regulates sex hormones including testosterone.  SHGB binds with testosterone causing the testosterone to not be available for use.  SHGB increases as we age, which decreases the amount of free testosterone in our body.

 

Luteinizing Hormone (LH)

LH is released by the pituitary gland and stimulates the Leydig cells in the testes to produce testosterone.  Low testosterone levels with an elevated LH level indicates an issue with the testes producing testosterone and is termed primary hypogonadism.

 

Follicle Stimulating Hormone (FSH)

FSH is vital to male fertility as it is released by the pituitary gland and stimulates the Sertoli cells in the testes to produce sperm.  Low testosterone levels with an elevated FSH indicates an issue with the testes and is termed primary hypogonadism.

 

Estradiol

Estradiol is a hormone in a class of hormones referred to as estrogens.  Estrogen in men is normal and small concentrations are required for normal functions of several organs in the male body.  Estradiol is produced as a byproduct from the breakdown of testosterone.  When treating low testosterone, it is important to balance both testosterone and estradiol hormone levels in order to fully improve your symptoms.​