SHBG IS A PROTEIN MADE BY YOUR LIVER, THIS HORMONE CARRIES THREE TYPE OF HORMONE THROUGHOUT YOUR BLOOD IN MEN AND WOMEN (ESTROGEN, DIHYDROTESTOSTERONE, TESTOSTERONE). THE LEVEL OF SHBG CAN CHANGE IN YOUR BLOOD BECAUSE OF YOUR SEX, AGE, IT CAN ALSO CHANGE BECAUSE OF OBESITY, LIVER DISEASE, AND HYPERTHYROIDISM. THE CRITICAL HORMONE IN THIS TEST IS THE TESTOSTERONE; IN MEN HAVING A LOW LEVEL OF TESTOSTERONE, AND HIGH LEVEL OF TESTOSTERONE IN WOMEN CAN CAUSE PROBLEMS.