There may be medical causes to these disorders, such as decreased blood flow or lack of vaginal lubrication. Chronic disease can also contribute, as well as the nature of the relationship between the partners. As the success of sildenafil (Viagra) attests, most erectile disorders in men are primarily physical, not psychological conditions.
Orgasm disorders are a persistent delay or absence of orgasm following a normal sexual excitement phase. The disorder can occur in both women and men. Again, the SSRI antidepressants are frequent culprits -- these can delay the achievement of orgasm or eliminate it entirely.
The problem of an inadequate erection is probably one of the biggest issues a man confronts. Most men experience erectile problems on occasion, but impotence, also called erectile dysfunction, is defined as "the persistent failure to develop and maintain erections of sufficient rigidity for penetrative sexual intercourse." Of course, men have other kinds of sexual problems including lack of desire and problems with ejaculation, yet impotence is the most common and troubling.
A recent study estimates that 30 million men suffer from various degrees of erectile dysfunction. This can range from mild to severe. It is clearly an age-related phenomenon with the prevalence of erectile dysfunction increasing significantly with age. Surprisingly, by the time men reach 40, 5% of them are completely impotent never achieving an erection rigid enough for penetration. Approximately 15% have significant problems achieving or maintaining an erection.
Sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis) drugs can cause minor side effects such as flushing and headache, but they have been shown to be safe in most men, including those with heart disease. However, these drugs can interact with other medications and cause dangerously low blood pressure. In particular, they should never be taken with nitroglycerin or other nitrate medications commonly used to treat heart disease. Men with enlarged prostates who take alpha-blocker drugs such tamsulosin (Flomax) or doxazosin (Cardura) should probably avoid PDE5 drugs.