Premature ejaculation (PE) is the most common sexual dysfunction in men younger than 40 years. Most professionals who treat premature ejaculation define this condition as the occurrence of ejaculation prior to the wishes of both sexual partners. This broad definition thus avoids specifying a precise duration for sexual relations and reaching a climax, which is variable and depends on many factors specific to the individuals engaging in intimate relations. An occasional instance of premature ejaculation might not be cause for concern, but, if the problem occurs with more than 50% of attempted sexual relations, a dysfunctional pattern usually exists for which treatment may be appropriate.
To clarify, a male may reach climax after 8 minutes of sexual intercourse, but this is not premature ejaculation if his partner regularly climaxes in 5 minutes and both are satisfied with the timing. Another male might delay his ejaculation for a maximum of 20 minutes, yet he may consider this premature if his partner, even with foreplay, requires 35 minutes of stimulation before reaching climax. If intercourse is the method of sexual stimulation for the second example and the male climaxes after 20 minutes of intercourse and then loses his erection, satisfying his partner (at least with intercourse), who needs 35 minutes to climax, is impossible.
Because many females are unable to reach climax at all with vaginal intercourse (no matter how prolonged), this situation may actually represent delayed orgasm for the female partner rather than premature ejaculation for the male; the problem can be either or both, depending on the point of view. This highlights the importance of obtaining a thorough sexual history from the patient (and preferably from the couple).
The human sexual response can be divided into 3 phases: desire (libido), excitement (arousal), and orgasm. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) classifies sexual disorders into 4 categories: (1) primary, (2) general medical condition–related, (3) substance-induced, and (4) not otherwise specified. Each of the 4 DSM-IV categories has disorders in all 3 sexual phases.
Premature ejaculation may be primary or secondary. Primary applies to individuals who have had the condition since they became capable of functioning sexually (ie, postpuberty). Secondary indicates that the condition began in an individual who previously experienced an acceptable level of ejaculatory control, and, for unknown reasons, he began experiencing premature ejaculation later in life. With secondary premature ejaculation, the problem does not relate to a general medical disorder, and it is usually not related to substance inducement, although, rarely, hyperexcitability might relate to a psychotropic drug and resolves when the drug is withdrawn. Premature ejaculation fits best into the category of not otherwise specified because no one really knows what causes it, although psychological factors are suggested in most cases.