The Majority of testosterone circulating within the blood is bound to proteins, in particular SHBG and albumin only 2-3% of testosterone is free and available to cells. The test uses an algorithm to calculate the level of free or unbound testosterone in relation to total testosterone, SHBG and albumin.

A lower level in a male could lead to symptoms which include low libido, erectile dysfunction, depression and a difficulty in gaining muscle mass.

In women an increased level could be an indication of polycystic ovary syndrome

Oestradiol is a steroid hormone that accounts for 80% of the oestrogen in the female body. It is secreted by the ovaries and is responsible for the development and maintenance of reproductive structures, including fat distribution, preparing the follicle in the ovary for the release of an egg and helping to maintain bone density. This blood test measures the level of oestradiol in your body.

Testosterone, oestrogen and dihydrotestosterone are all bound to sex hormone binding globulin (SHBG) which means that they are unavailable to your cells. Measuring the levels of SHBG in the blood gives important information about your levels of free or unbound hormones which are biologically active and available for use.

Albumin is mostly made in your liver and helps to keep the blood from leaking out of blood vessels. It also helps carry medicines through the blood and is important for tissue growth and healing.

Lower albumin levels may be an indication of a liver disease and can also be an indication of chronic ill-health, malnutrition and inflammation. It can also occur in kidney conditions such as nephrotic syndrome and diabetes.

higher levels are usually caused by dehydration.