Why are pituitary hormones (LH & FSH) levels measured?
Testing of LH and FSH levels can help with diagnosing the cause of the androgen deficiency. If testosterone levels fall, the hypothalamus and pituitary gland respond by increasing LH and FSH production to activate the Leydig cells within the testes to produce more testosterone. A low testosterone level together with a higher than normal LH level may mean that a testicular problem is the cause of the androgen deficiency. Low levels of both testosterone and LH may point to there being a pituitary/hypothalamus problem as the cause of androgen deficiency. High levels of FSH usually mean that sperm production is damaged, and together with low testosterone levels, points to a testicular problem being the cause of the androgen deficiency.
