Diagnosis of Priapism

The diagnosis of priapism is typically made with a medical history and examination. Differentiating between high and low flow priapism is important because the treatment varies. Low flow priapism needs to be diagnosed or excluded urgently as prolonged low flow priapism can cause permanent erectile dysfunction.


    It is important to differentiate between a low flow and a high flow priapism

  • Medical history
  • The usual time period before a diagnosis of priapism is made is four hours. It is important to differentiate between a low flow priapism and a high flow priapism. In patients with high flow priapism a history of trauma to the genital area is almost always present. In this case the patient may still complain of pain as a result of the trauma but the actual erection is not usually painful. Patients with low flow priapism will complain of a very painful, prolonged erection.

    Other important factors to determine in the history are the presence of any known medical diseases or symptoms which are pathological. History of all medication and any drug use should also be reported in the history.

  • Medical examination
  • On examination of the penis, an erect penis is present. Often the glans (the tip of the penis) is not involved and is flaccid. A thorough medical exam is always important. An enlarged spleen may be felt with is indicative of leukaemia. Unusual lymph nodes may also alert the medical professional to some other type of cancer.

    Piesis sign may be present in young children with high-flow priapism. When the perineal area is compressed, Piesis sign occurs if the compression results in detumescence of the penis.


    A blood sample can be taken from the penis by the doctor

  • Bloods
    • A blood sample can be taken from the penis by the doctor. This can determine the oxygen content of the blood and therefor the type of priapism the patient has. A high oxygen content in the blood (arterial blood) will signify high flow priapism.
    • A full blood count which measures red cells, white cells and platelets can also help establish the cause of priapism.
    • Blood for coagulation studies may also be useful.
  • Doppler Studies of the penis
  • If a diagnosis of high flow priapism is suspected, an ultrasound Doppler study can be done to determine where there is arterial injury. A low-flow priapism can also be diagnosed with Doppler studies of the penis by viewing occlusive blood flow.

  • Angiogram of penis
  • In patients with high flow priapism an angiogram is done to determine the location of the injured arteries or fistula. An angiogram of the penis is usually done before surgical repair to determine the exact site of injury.