A normal erection occurs in response to sexual stimulation. Priapism occurs in several conditions that interfere with the blood flow to the penis or blood drainage from the penis. This condition is unrelated to sexual stimulation and can last for several hours. The condition develops when blood in the penis becomes trapped and is unable to drain. If the condition is not treated immediately, it can lead to scarring and permanent erectile dysfunction. Priapism can occur in all age groups, including newborns. However, it usually affects men in two different age groups: between the ages of 5 and 10, and 20 and 50.

Two types of priapism: 

• Low-flow priapism: This is the result of blood being trapped in the erection chambers. It often occurs without a known cause in men who are otherwise healthy, but it also affects men with sickle-cell disease, leukemia (cancer of the blood), or malaria.
• High-flow priapism: This is rarer and is usually not painful. It is the result of a ruptured artery from an injury to the penis or the perineum (the area between the scrotum and anus), which prevents blood in the penis from circulating normally.

Priapism is usually divided into three categories

• Ischemic priapism is the most common category of priapism. Blood is not able to leave the penis causing the erection. This painful event is considered an emergency if it lasts for more than 4 hours.
• Non-ischemic (high-flow) priapism is the second category of priapism, and much less common. In this form, too much blood flows into the penis. The erection tends to be painless and less rigid than the ischemic form.
• Stuttering priapism is the third category of priapism. In stuttering priapism, the erection occurs repeatedly but is transient in nature.

What causes priapism?

• Sickle cell anemia: Some adult cases of priapism are the result of sickle-cell disease.
• Medications: A common cause of priapism is the use and/or misuse of medications, including drugs such as Desyrel (used to treat depression or as a sleeping aid) or Thorazine (used to treat certain mental illnesses). For people who have erectile dysfunction, injection therapy medications to treat the condition may also cause priapism.

Other causes of priapism include:

• Trauma to the spinal cord or to the genital area.
• Black widow spider bites.
• Carbon monoxide poisoning.
• Drug use, such as marijuana and cocaine.

In rare cases, priapism may be related to cancers that can affect the penis and prevent the outflow of blood.

What are the complications of priapism?

Ischemic priapism can cause significant complications. Due to the lack of oxygen, there can be significant damage if priapism lasts for more than four hours. The complications include erectile dysfunction as well as disfigurement of the penis.

How is priapism treated?

The goal of all treatment is to make the erection go away and preserve the ability to have erections in the future. If a person receives treatment within four to six hours, the erection can almost always be reduced with medication. If the erection has lasted less than four hours, decongestant medications, which may decrease blood flow to the penis, may be very helpful. Other treatment options include:

• Ice packs: Ice applied to the penis and perineum may reduce swelling.
• Surgical ligation: Used in some cases where an artery has been ruptured, the doctor will ligate (tie off) the artery that is causing the priapism in order to restore normal blood flow.
• Intracavernous injection: This treatment is used for low-flow priapism. Drugs known as alpha-agonists are injected into the penis. They cause the arteries to narrow, reducing blood flow to the penis and causing the swelling to decrease.
• Surgical shunt: Also used for low-flow priapism, a shunt is a passageway that is surgically inserted into the penis to divert the blood flow and allow circulation to return to normal.
• Aspiration: After numbing the penis, doctors will insert a needle and drain blood from the penis to reduce pressure and swelling.

Can priapism be prevented?

Priapism or recurrence of priapism can be prevented by treating the underlying medical cause that resulted in priapism or changing medications that have priapism as their side effects. No medications should be discontinued or changed until you speak with your healthcare provider.

Written by Dude Arnel Flores Lopez, BSN, RN  20 April 2021

Medically reviewed and updated by Dr.Deyn Natthakhet Yaemim, 24 April 2021