Testosterone BIO With Sex Hormone Binding Globulin (SHBG) Blood Test

What is the purpose of this test?

Order this Testosterone BIO with Sex Hormone Binding Globulin (SHBG) Blood Test to measure free testosterone, total testosterone, and SHBG levels in a blood sample and help screen for a testosterone excess or deficiency. Testosterone is a primary hormone essential to the development of male physical features and reproductive functions, such as:

• Development of body hair, muscle growth, and a deepening voice
• Regulate sex drive, sustain muscle mass, and helps produce sperm in the testes (testicles)

It should be noted that women also make testosterone but in much smaller amounts in the ovaries and adrenal glands. There are two major forms of testosterone in the body commonly measured to help diagnose specific health problems: free and total testosterone. Free testosterone is the active or unbound form of testosterone that acts as a receptor to cells in the body. However, total testosterone includes unbound and bound testosterone attached to proteins (SHBG or albumin). Sex Hormone Binding Globulins (SHBG) are proteins produced by the liver that binds to sex hormones, such as dihydrotestosterone (DHT), testosterone, and estradiol (an estrogen). Once attached to the hormones, they transport them through the bloodstream in a metabolically inactive form. 

What causes abnormal testosterone and SHBG levels?

Several underlying health factors may affect testosterone and SHBG levels. For example, testosterone and SHBG levels are affected by an individual's sex and age. Although testosterone levels decrease with age for men, abnormally low levels may indicate a testosterone deficiency. Additionally, low levels of testosterone in men can be related to other health issues, including:

• Changes in thyroid function
• Genetic or chronic illness
• Benign tumors
• Problems with the testicles
• Obesity
• Disturbed sleep

However, for women, abnormal testosterone levels may indicate excess testosterone production by the ovaries or other glands that produce sex hormones. For instance, abnormal testosterone results may be caused by the following:

• Polycystic ovary syndrome (PCOS)
• Cancer of the ovary or adrenal gland
• Pituitary gland disorder

When should I order a Testosterone BIO with Sex Hormone Binding Globulin (SHBG) Blood Test?

Individuals may order this test if they have experienced the symptoms related to a testosterone excess or deficiency. Common signs or symptoms of a testosterone excess or deficiency may include:

• Early or delayed puberty
• Erectile dysfunction (ED)
• Fertility problems
• Osteoporosis or thinning of the bones
• Decrease in sex drive
• Irregular periods
• Loss of periods
• Changes in hair growth patterns
• Voice changes
• Skin changes such as oily skin or acne