Priapism is painful and can result in long-term damage to the penis
In many cases, the cause of priapism is unknown, but it is thought that it could be due to nerve damage or a side effect of some types of medication, such as drugs for erectile dysfunction. It may also be caused by conditions that affect the blood, such as sickle-cell anaemia or leukemia, or by an injury to the penis or genital area.
If it's been less than four hours, then you can try to get your erection to go down by taking gentle exercise such as jogging, or taking a warm bath at home. It can also help to pass urine (this may be easier in a warm bath), while painkillers might go some way to relieving the discomfort priapism causes.
However, if none of these methods work or if you've had a painful erection for more than four hours, then it is important that you go to accident and emergency to be seen by a doctor as soon as possible.
The treatment for this condition may involve taking medication or draining blood from the penis using a syringe. If the priapism was caused by an underlying medical condition, this will also need to be addressed to prevent the problem occurring again.
If other treatments don't work, surgery may be necessary to prevent permanent damage. There are a number of different surgical procedures available to treat the condition, depending on the type of priapism you have, and most men come through them without any serious side effects.