This test measures the amount of unattached, or "free," testosterone in your blood. Testosterone is a male sex hormone androgen that helps male features develop. Testosterone is made in the testes and the adrenal glands. It causes the changes that occur in boys during puberty. Testosterone helps hair and muscles grow.

A cross-sectional study was performed to see if the previously described association between high density lipoprotein HDL cholesterol and plasma total testosterone concentration reflected a relationship with free testosterone or with sex hormone binding globulin SHBG. In employed middle-aged men, measurements were made of total testosterone and SHBG in serum and of testosterone in saliva, and also of plasma total and HDL cholesterol, plasma triglycerides and other factors which might influence HDL cholesterol levels such as body mass index, alcohol and smoking habits and thyroid hormone levels. The association of HDL cholesterol with testosterone was independent of and stronger than the association of HDL cholesterol with body mass index, alcohol intake and cigarette smoking. Salivary testosterone a measure of the circulating free hormone also had a positive independent association with HDL cholesterol. The relationship between HDL cholesterol and testosterone thus appears to reflect an association with circulating hormone levels rather than with the hormone binding globulin.

Written by Libby Pellegrini. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields. And because testosterone is a key hormone in the body—in women and men alike—a testosterone imbalance can have quite an impact on your health and well-being. So keep reading to learn more about unhealthy levels of testosterone in women—including causes and symptoms.