Testosterone maintains male secondary sexual characteristics and is produced by the testis, ovaries and adrenal glands. Excessive production leads to premature puberty in males and masculization in females. Testosterone exists in a free form (active form) and a bound form (inactive), bound to albumin, sex hormone binding globulin or testosterone binding globulin.
Testosterone peaks in early morning hours in males and peaks 1-2 days after the mid-cycle in females. Testosterone levels are normal in cryptorchidism, azoospermia and oligospermia.
TOTAL TESTOSTERONE LEVELS (MALES) ARE INCREASED IN:
- Hyperthyroidism
- Syndromes of androgen resistance
- Adrenal tumors
- Precocious puberty and adrenal hyperplasia
- Steroid therapy
- Estrogen therapy
TOTAL TESTOSTERONE LEVELS (MALES) ARE DECREASED IN:
- Hypogonadism
- Klinefelter’s syndrome
- Hypopituitism
- Orchidectomy
- Hepatic cirrhosis
- Down’s syndrome
- Delayed puberty
- Alcoholism
Total testosterone levels (females) are increased in:
- Adrenal neoplasms
- Ovarian tumors (virilizing)
- Trophoblastic disease during pregnancy
- Idiopathic hirsutism
- Hilar cell tumor
TOTAL TESTOSTERONE ng/dL nmol/L
Men 270-1070 9-38
Women 15-70 0.52-2.4
Pregnant women 3-4 times normal
Postmenopausal 8-35 0.3-1.2
Children 2-20 0.07-0.7 (depends on age)