Priapism is a prolonged erection of the penis. The unwanted, persistent erection isn’t caused by sexual stimulation or arousal and priapism is usually painful.

Priapism is an uncommon condition that needs immediate medical attention. Prompt treatment for priapism is usually needed to prevent tissue damage that could result in the inability to get or maintain an erection (erectile dysfunction).

Priapism is most common in boys between ages 5 and 10 years old and in men from ages 20 to 50 years.


Priapism causes abnormally persistent erections. Priapism symptoms vary somewhat depending on the type of priapism.

Ischemic, or low-flow, priapism is the result of blood not being able to leave the penis. It’s the most common type of priapism. Signs and symptoms include:

  • Unwanted erection lasting more than four hours
  • Rigid penile shaft, but usually soft tip of penis (glans)
  • Erection not related to sexual stimulation or persistent after stimulation
  • Usually painful or tender penis

Nonischemic priapism

Nonischemic, or high-flow, priapism occurs when too much blood flows into the penis. Signs and symptoms include:

  • Unwanted erection lasting at least four hours
  • Erect but not rigid penile shaft
  • Erection not related to sexual stimulation or persistent after stimulation
  • Usually painless

Stuttering priapism

Another type of ischemic priapism, stuttering, or recurring, priapism occurs off and on. A stuttering erection is usually painful and generally lasts several hours.

When to see a doctor: Go to the emergency room if you have an erection lasting longer than four hours.

If you experience a painful, persistent erection that resolves on its own in less than four hours, see your doctor, because you may need treatment to prevent further episodes.


An erection normally occurs in response to physical or psychological stimulation. This stimulation causes certain blood vessels to relax and expand, increasing blood flow to spongy tissues in the penis. Consequently, the blood-filled penis becomes erect.

After stimulation ends, the blood flows out and the penis returns to its nonrigid (flaccid) state.

Priapism occurs when some part of this system — the blood, blood vessels or nerves — changes normal blood flow. Subsequently, an unwanted erection persists. Factors that can contribute to priapism include the following.

Blood disorders

Blood-related diseases may contribute to priapism — usually ischemic priapism, a persistent erection caused by blood not being able to flow from the penis. These disorders include:

  • Sickle cell anemia
  • Leukemia

Sickle cell anemia, a common cause of priapism, is an inherited disorder characterized by abnormally shaped red blood cells. These abnormally shaped cells can block the flow of blood. Sickle cell anemia is the most common cause of priapism in boys.

Prescription medications

Priapism, usually ischemic priapism, is a known side effect of a number of drugs. The following drugs can sometimes cause priapism:

  • Oral medications used to manage erectile dysfunction, such as sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra)
  • Drugs injected directly into the penis to treat erectile dysfunction, such as papaverine
  • Antidepressants, such as fluoxetine (Prozac) and bupropion (Wellbutrin)
  • Drugs used to treat psychotic disorders, such as risperidone (Risperdal) and olanzapine (Zyprexa)
  • Blood thinners, such as warfarin (Coumadin) and Heparin

Illegal drug use

Some illegal drugs or the abuse of drugs can cause priapism, particularly ischemic priapism. Possible causes include:

  • Recreational use of erectile dysfunction drugs
  • Drinking too much alcohol
  • Use of illegal drugs such as marijuana or cocaine


A common cause of nonischemic priapism — a persistent erection caused by excessive blood flow into the penis — is trauma or injury to your genitals, pelvis or the perineum, the region between the base of the penis and the anus.

Other factors

Other causes of priapism include:

  • Spinal cord injury
  • Blood clots
  • Poisonous venom, such as venom from scorpions or black widow spiders
  • In some cases, doctors are unable to identify the specific cause for priapism.


Ischemic priapism

Ischemic priapism — the result of blood not being able to exit the penis — is an emergency situation that requires immediate treatment. This treatment usually begins with a combination of draining blood from the penis and using medications.


After your penis is numbed with local anesthetic, excess blood is drained from it, using a small needle and syringe. As part of this procedure, the penile veins may also be flushed with a saline solution. This treatment relieves pain, clears the tissues of oxygen-poor blood and may stop the erection. This treatment may be repeated until the erection ends.


Injection of a drug called an alpha-adrenergic sympathomimetic, such as phenylephrine, may be injected into the spongy tissue of the penis. This drug constricts blood vessels transporting blood into the penis, thereby limiting blood flow in.

This action allows blood vessels transporting blood out of the penis to open up, allowing increased blood flow out. This treatment may be repeated frequently over several hours if necessary. There is some risk of side effects, such as headache, dizziness and elevated blood pressure.


If other treatments aren’t successful, a surgeon may implant a shunt, a device that reroutes blood flow so that it moves through your penis normally.

Additional Treatments

If you have sickle cell anemia, you may receive additional treatments that are used to treat disease-related episodes, such as supplemental oxygen or an intravenous solution to keep you well hydrated.

Nonischemic Priapism

Nonischemic priapism often goes away with no treatment. Because there isn’t a risk of damage to the penis, your doctor may suggest a watch-and-wait approach. Putting ice and pressure on the perineum — the region between the base of the penis and the anus — may help end the erection.