Loss of Libido and Sexual Sensation
You may have more than one problem. Decreased libido, a loss of interest in sex, and the inability to maintain an erection may all be due to an inadequate level of testosterone (also called hypogonadism). However, it is also possible that your inability to maintain an erection comes secondary to the loss of libido, due to psychological concerns like performance anxiety.
Your testosterone level — including the free and total level – should be obtained at 8 a.m. and ideally should be checked on two separate occasions before making the diagnosis of hypogonadism. If testosterone levels are low, then additional studies need to be performed to make sure there are not pituitary gland (a gland in the brain that regulates hormone secretion) causes of the low hormone level.
Sleep apnea is associated with a higher risk of erectile dysfunction, and in overweight or obese patients, the obesity itself, in addition to causing sleep apnea, is associated with a higher risk of erectile dysfunction as well as low testosterone levels.
Diabetes imparts the highest risk of erectile dysfunction of all medical comorbid conditions and can also cause low hormone levels.
In summary, erectile dysfunction and low sexual desire may be two separate problems, and both issues need a careful evaluation. This is probably best performed in a specialty setting, either by a urologist who has experience treating sexual dysfunction or an endocrinologist with experience in this area. Evaluation of these conditions starts with a careful history and a physical examination, including laboratory testing. If the patient does in fact have both hypogonadism and erectile dysfunction, we often treat these conditions separately with testosterone replacement therapy on the one hand and oral medications like Viagra, Cialis, or Levitra on the other.