Causes of Priapism

Priapism often occurs without any sexual stimulation or desire. In about one third of cases of patients with priapism no cause can be found.
In children, the most common cause of priapism is sickle cell disease and leukaemia. In adults, the most common reason for priapism is because of the treatment of erectile dysfunction, especially the penile injection.
The causes of priapism are mentioned and briefly discussed:


    Injection of intra-cavernosal vasoactive substances

  • Treatment of erectile dysfunction
  • The most common cause of priapism in men above 40 years of age is from the injection of intra-cavernosal vasoactive substances. This often happens when the patient injects too much of the drug into his penis, or if he uses it too regularly. That is why patients are encouraged to use medications as directed. If the medication was used as directed and priapism still occurs the man should report to his healthcare provider for a possible change in dosage or seek alternative management of his erectile dysfunction.


    There are many medications which have been reported to cause priapism as one of its side effects

  • Medications
  • There are many medications which have been reported to cause priapism as one of its side effects. Medications used to treat erectile dysfunction, like Sildanifil (Viagra) and Testosterone, have been reported to cause priapism. Even supplements which are considered as a “natural” treatment of erectile dysfunction like Yohimbe supplements can cause priapism. Other medications known to be linked to priapism are anti-depressants, anti-psychotics, anti-coagulants (warfarin) and Prazosin (Alpha-adrenergic blocker).

  • Recreational drugs
  • Consumption of alcohol and drugs like cocaine, ecstasy and marijuana have also been reported to be a cause of priapism. Cocaine abuse may cause recurrent episodes of priapism and eventual impotency.

  • Illnesses
    • Sickle cell disease
    • Sickle cell disease is an inherited blood disorder which affects the shape of red blood cells. About 42% of adult males with sickle cell disease develop priapism. People of African and Caribbean descent are more likely to have sickle cell disease.

    • Leukaemia
    • Priapism can sometimes be the first presentation of leukaemia which is commonly known as blood cancer. Different types of leukaemia can present with priapism. The incidence of priapism in patients with leukaemia has been estimated to be about 5%.

    • Malaria
    • Priapism can occur in patients affected with Vivax malaria.

    • Pelvic tumours and pelvic infections
    • Pelvic tumours and pelvic infections can cause priapism either by compressing vessels or by affecting blood coagulation and flow.

    • Other illnesses

    Although rare, diabetes, renal failure, gout, multiple myeloma and amyloidosis have been linked to playing a role in the cause of priapism.

  • Spinal cord problems
  • Priapism has been reported in a wide range of spinal pathologies including spinal cord injuries and spinal cord lesions. Injury of the cerebellum can also result in priapism.

  • Trauma to the genitals
  • Trauma to the genitals or to the genital area may result in arterial injury which can be a cause of high flow priapism. Occasionally the development of priapism is delayed because the artery involve may still be in spasm or a clot may have developed. Once the spasm and clot clear up, priapism occurs.

  • Rare causes
    • Carbon monoxide poisoning
    • Chronic and acute carbon monoxide poisoning may cause priapism.

    • Black Widow spider bite

    This is a rare cause of priapism but cases have been reported. Not all black widow spider bites result in priapism.