These motor neurons are located in the thoracolumbar and lumbosacral spinal cord and are activated in a coordinated manner when sufficient sensory input to reach the ejaculatory threshold has entered the central nervous system. Intromission time
The 1948 Kinsey Report suggested that three-quarters of men ejaculate within two minutes of penetration in over half of their sexual encounters.Current evidence supports an average intravaginal ejaculation latency time (IELT) of six and a half minutes in 18- to 30-year-olds. If the disorder is defined as an IELT percentile below 2.5, then premature ejaculation could be suggested by an IELT of less than about two minutes. Nevertheless, it is possible that men with abnormally low IELTs could be satisfied with their performance and do not report a lack of control. Likewise, those with higher IELTs may consider themselves premature ejaculators, have detrimental side effects normally associated with premature ejaculation, and even benefit from treatment. Diagnosis
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) defines premature ejaculation as "A persistent or recurrent pattern of ejaculation occurring during partnered sexual activity within approximately 1 minute following vaginal penetration and before the person wishes it," with the additional requirements that the condition occurs for a duration longer than 6 months, causes clinically significant distress, and cannot be better explained by relationship distress, another mental disorder, or the use of medications. These factors are identified by talking with the person, not through any diagnostic test.
Premature ejaculation (PE) occurs when a man expels semen (and most likely experiences orgasm) soon after beginning sexual activity, and with minimal penile stimulation. It has also been called early ejaculation, rapid ejaculation, rapid climax, premature climax and (historically) ejaculatio praecox. There is no uniform cut-off defining "premature", but a consensus of experts at the International Society for Sexual Medicine endorsed a definition of around one minute after penetration. The International Classification of Diseases (ICD-10) applies a cut-off of 15 seconds from the beginning of sexual intercourse.Although men with premature ejaculation describe feeling that they have less control over ejaculating, it is not clear if that is true, and many or most average men also report that they wish they could last longer. Mens typical ejaculatory latency is approximately 4–8 minutes. The opposite condition is delayed ejaculation.Men with PE often report emotional and relationship distress, and some avoid pursuing sexual relationships because of PE-related embarrassment. Compared with men, women consider PE less of a problem, but several studies show that the condition also causes female partners distress. Cause
The causes of premature ejaculation are unclear. Many theories have been suggested, including that PE was the result of masturbating quickly during adolescence to avoid being caught, performance anxiety, passive-aggressiveness or having too little sex; but there is little evidence to support any of these theories.Several physiological mechanisms have been hypothesized to contribute to causing premature ejaculation, including serotonin receptors, a genetic predisposition, elevated penile sensitivity and nerve conduction atypicalities.