First, we have to define it! The ISSM (International Society for Sexual Medicine) uses the definition of " ... ejaculation which always or nearly always occurs prior to or within about one minute of penetration, the inability to delay ejaculation on all or nearly all penetrations, and the presence of negative personal consequences, such as distress, bother, frustration and/or the avoidance of sexual intimacy." So when we look into this further, it's important to note that premature ejaculation isn't about ejaculating faster that what he would necessarily want. It's about ejaculating very quickly (some prior definitions used 2 minutes as the time frame), without being able to stop it, and probably the most important criteria, it needs to present itself as a problem. Because if it doesn't bother the patient and/or his partner, then it isn't a problem.
What causes premature ejaculation is still somewhat of a mystery. The theories range from the biological to the psychological, and all points in-between. In reality, there are probably multiple different answers which overlap. The theories range from: neuro-chemical/biological, concurrent urological problems including inflammation and ED, Thyroid disorders, hormonal imbalances (i.e. testosterone), anxiety and its influence on the nervous system ...
Are there ways to prevent it? Unfortunately, the current answer is no. In order to prevent an event, a basic understanding of what causes it, needs to be understood. Which, sadly, we do not have yet. The best advice for limiting the negative effects of premature ejaculation is awareness and education, with early evaluation and treatment.
Increasing endurance, otherwise referred to as treatment of premature ejaculation, can often be accomplished. It starts with a proper evaluation of the patient, including history and physical to determine possible causes for the dysfunction. If something is found, treatment of the underlying cause, can often resolved the premature ejaculation. If nothing specific is identified then there are several options available. First, patient education is an important step, limiting anxiety and optimizing treatment results. Medication does exist to help the problem, they can be given daily or even on-demand, these are often the SSRIs which have been shown to significantly delay ejaculation. Topical anesthetics have also been used with success. They were often dismissed in the past, as following application to the penis it was transferred to the partner with resulting de-sensitization. Newer technologies now allow the absorption with significantly reduced transfer. Counseling, has also shown to have a significant benefit to pt's with PE. It allows pts to become more at ease with the problem, help them develop techniques to increase partner satisfaction and length