What happens if my sex drive (libido) is low? What causes it, can it be treated?

Your interest in sex is governed by sex hormones^[1], primarily testosterone, and by psychosocial factors. Low testosterone levels are associated with decreased libido. Stress, depression, or anxiety may also affect your libido. In men with erectile dysfunction, interest in sex may be diminished as a result of their inability to achieve an adequate erection.

Any man with decreased libido should have his serum testosterone level checked. Normally, there is a feedback loop between the brain and the testes^[2]. The brain, through the release of luteinizing hormone (LH), tells the testicles to produce testosterone. The production of testosterone by the testicles acts on the brain to decrease the release of LH. If the testicles don't produce enough testosterone, the brain releases more LH in an attempt to stimulate the testicles to produce more testosterone. If the brain does not release enough LH, the testicles won't produce enough testosterone. This problem may occur in men with brain tumors or congenital abnormalities.

Another problem that can affect testosterone production is overactivity of the pituitary gland. The pituitary gland is a gland in the brain that is comprised of an anterior lobe and a posterior lobe. The anterior lobe produces such hormones as luteinizing hormone and prolactin. Overactivity of the pituitary gland can be caused by a pituitary adenoma (benign [noncancerous] tumor of the pituitary gland). This abnormality can lead to an elevated prolactin level, which in turn suppresses testosterone production.

Abnormalities of the testicles themselves that lead to impaired function of the testes may cause the testosterone levels to be low. Such abnormalities may include a history of testicular torsion, a history of undescended testes, prior testicular infections, and other congenital anomalies that affect the testes. Removal of both testes (bilateral orchiectomy) for prostate cancer or (rarely) bilateral testicular cancers causes a significant drop in testosterone level and decreases libido. Men with a single testis usually have adequate testosterone production, provided that the remaining testis is normal.

Testosterone levels do decrease as one ages, but this does not usually cause problems with libido.

If you have decreased libido and your testosterone level is low then you may benefit from testosterone replacement therapy (see Question 76). Men with prostate cancer on LHRH agonist hormonal therapy will have a low testosterone level and may suffer from associated low libido. In these men, testosterone replacement therapy is contraindicated, and there would need to be a conscious effort to think about sex. Similarly, individuals who are stressed or depressed may experience low libido, and if their testosterone level is normal, administration of testosterone replacement therapy would not be beneficial.

Are there different types of problems with ejaculation? What causes them and how are they treated?

There are three different types of ejaculatory problems that can occur: premature ejaculation, retrograde ejaculation, and anejaculation.

What is premature ejaculation and what causes it?

Premature ejaculation is ejaculation that occurs sooner than desired, either before or shortly after penetration, that causes distress to one or both partners. This condition tends to occur more frequently in younger men. Premature ejaculation is the most common form of sexual dysfunction, occurring in 21% of men ages 18 to 59 years in the United States. The condition may be lifelong (primary) or acquired (secondary). Despite its prevalence, men rarely seek help. Some men with ED may develop secondary premature ejaculation, possibly caused by either the need for intense stimulation to attain and maintain an erection or because of anxiety associated with difficulty in attaining and maintaining an erection. In these patients, treating the erectile dysfunction may lead to resolution of the premature ejaculation.

It appears that men with premature ejaculation may have an increased sensitivity and excitability of the glans penis and the dorsal nerve, which supplies sensation to the penis.

• [1] Substances (estrogens and androgens) responsible for secondary sex characteristics (e.g., hair growth and voice change in males).
• [2] One of two male reproductive organs that are located within the scrotum and produce testosterone and sperm.