Testosterone Free, Serum

Serum Testosterone levels are tested to diagnose several pathological conditions in men, women, girls and boys. Testosterone is the main sex hormone in the male body. It is produced mainly by they the testicles, and is responsible for the male physical characteristics. Though it is a male sex hormone, it is present in both males and females. The serum testosterone levels are used to evaluate early or delayed puberty in boys, erectile dysfunction in males, infertility, testicular tumors, pituitary or hypothalamus disorders, hirsutism and virilization in females. Most of the testosterone in the body is bound to proteins like albumin and sex hormone binding globulin. 2/3rd is bound to sex hormone binding globulin and 1/3rd with albumin. Less than 4% circulates in the body as free testosterone. The total testosterone test measures both bound and free forms. Bioavailable testosterone is free testosterone plus the testosterone bound to albumin, which can act on target tissues. Bioavailable testosterone test may be performed when the level of SHBG is abnormal as it more accurately reflect the presence of a medical condition. Depending on the underlying medical condition, additional tests like SHBG, FSH, LH, Estrogens, DHEAS, Prolactin, 17-Hydroxyprogesterone, Androstenedione may be needed.

1. Will testosterone supplements help in cases of low testosterone levels?

Maybe. Testosterone supplements are available as gels, patches or injections may raise the testosterone levels. Testosterone supplements may help to relieve some symptoms and/or prevent muscle and bone loss that occurs with aging in men. The testosterone administration may increase the risk of heart attack and stroke. Testosterone administration does not improve the symptoms of erectile dysfunction in males as there may be other underlying causes.

2. Do woman need to get serum testosterone levels checked?

Testosterone is produced in small quantities in women as well. It is required for maintaining hormonal balance and normal functioning of the body. High levels can cause increased body hair, abnormal or no menstrual periods or infertility. Serum testosterone test along with other hormone assays can diagnose the cause of the above symptoms.

3. Does testosterone levels affect the amount of hair on the body?

Some studies have shown a proportional relationship of testosterone levels to the amount of hair on the body. The growth of hair in response to testosterone differs in different parts of the body. In some men, testosterone promotes hair growth on the abdomen and back while it suppresses hair growth on the scalp, leading to male pattern baldness.

4. What is free testosterone and bioavailable testosterone?

Most of the testosterone in the body is bound to proteins like albumin and sex hormone binding globulin. 2/3rd is bound to sex hormone binding globulin and 1/3rd with albumin. Less than 4% circulates in the body as free testosterone. The total testosterone test measures both bound and free forms.

Bioavailable testosterone is free testosterone plus the testosterone bound to albumin, which can act on target tissues.