Priapism is a prolonged erection of the penis. The persistent erection continues hours beyond or isn't caused by sexual stimulation. Priapism is usually painful.

Although priapism is an uncommon condition overall, it occurs commonly in certain groups, such as people who have sickle cell anemia. 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 most commonly affects men in their 30s and older.


Priapism symptoms vary depending on the type of priapism. The two main types of priapism are ischemic and nonischemic priapism.

Ischemic priapism

Ischemic priapism, also called low-flow priapism, is the result of blood not being able to leave the penis. It's the more common type of priapism. Signs and symptoms include:

  • Erection lasting more than four hours or unrelated to sexual interest or stimulation
  • Rigid penile shaft, but the tip of penis (glans) is soft
  • Progressive penile pain

Recurrent or stuttering priapism, a form of ischemic priapism, is an uncommon condition. It's more common in males who have an inherited disorder characterized by abnormally shaped red blood cells (sickle cell anemia). Sickle cells can block the blood vessels in the penis. Recurrent priapism describes repetitive episodes of prolonged erections and often includes episodes of ischemic priapism. In some cases, the condition starts off with unwanted and painful erections of short duration and might progress over time to more frequent and more prolonged erections.

Nonischemic priapism

Nonischemic priapism, also known as high-flow priapism, occurs when penile blood flow isn't regulated appropriately. Nonischemic priapism is usually less painful than ischemic priapism. Signs and symptoms include:

  • Erection lasting more than four hours or unrelated to sexual interest or stimulation
  • Erect but not fully rigid penile shaft

When to see a doctor

If you have an erection lasting more than four hours, you need emergency care. The emergency room doctor will determine whether you have ischemic priapism or nonischemic priapism. This is necessary because the treatment for each is different, and treatment for ischemic priapism needs to be done as soon as possible.

If you experience recurrent, persistent, painful erections that resolve on their own, see your doctor. You might need treatment to prevent further episodes.


An erection normally occurs in response to physical or psychological stimulation. This stimulation causes certain smooth muscles to relax, 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, smooth muscles or nerves — changes normal blood flow, and an erection persists. The underlying cause of priapism often can't be determined, but several conditions may play a role.

Blood disorders

Blood-related diseases might contribute to priapism — usually ischemic priapism, when blood isn't able to flow out of the penis. These disorders include:

  • Sickle cell anemia
  • Leukemia
  • Other hematologic dyscrasias, such as thalassemia, multiple myeloma and others

The most common associated diagnosis in children is sickle cell anemia.

Prescription medications

Priapism, usually ischemic priapism, is a possible side effect of a number of drugs, including:

  • Medications injected directly into the penis to treat erectile dysfunction, such as alprostadil, papaverine, phentolamine and others
  • Antidepressants, such as fluoxetine (Prozac), bupropion (Wellbutrin), and sertraline
  • Alpha blockers including prazosin, terazosin, doxazosin and tamsulosin
  • Medications used to treat anxiety or psychotic disorders, such as hydroxyzine, risperidone (Risperdal), olanzapine (Zyprexa), lithium, clozapine, chlorpromazine and thioridazine
  • Blood thinners, such as warfarin (Coumadin) and heparin
  • Hormones such as testosterone or gonadotropin-releasing hormone
  • Medications used to treat attention-deficit/hyperactivity disorder (ADHD), such as atomoxetine (Strattera)

Alcohol and drug use

Alcohol, marijuana, cocaine and other illicit drug abuse can cause priapism, particularly ischemic priapism.


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

Other factors

Other causes of priapism include:

  • A spider bite, scorpion sting or other toxic infections
  • Metabolic disorders including gout or amyloidosis
  • Neurogenic disorders, such as a spinal cord injury or syphilis
  • Cancers involving the penis


Ischemic priapism can cause serious complications. The blood trapped in the penis is deprived of oxygen. When an erection lasts for too long, this oxygen-poor blood can begin to damage or destroy tissues in the penis. As a result, untreated priapism can cause erectile dysfunction.


If you have recurrent or stuttering priapism, to prevent future episodes your doctor might recommend:

  • Treatment for an underlying condition, such as sickle cell anemia, that might have caused priapism
  • Use of oral or injectable phenylephrine
  • Hormone-blocking medications — only for adult men
  • Use of oral medications used to manage erectile dysfunction


If you have an erection lasting more than four hours, you need emergency care. The emergency room doctor will determine whether you have ischemic priapism or nonischemic priapism. This is necessary because the treatment for each is different, and treatment for ischemic priapism needs to be done as soon as possible.

Medical history and exam

To determine what type of priapism you have, your doctor will ask questions and examine your genitals, abdomen, groin and perineum. He or she might be able to determine what type of priapism you have based on whether you're experiencing pain and the rigidity of the penis. This exam might also reveal the presence of a tumor or signs of trauma.

Diagnostic tests

Diagnostic tests might be needed to determine what type of priapism you have. Additional tests might identify the cause of priapism. In an emergency room setting, your treatment will likely begin before all test results are received. Diagnostic tests can include:

  • Blood gas measurement. In this test, a tiny needle is inserted into your penis to remove a sample of blood. If the blood is black — deprived of oxygen — the condition is most likely ischemic priapism. If it's bright red, the priapism is more likely nonischemic. A lab test measuring the amounts of certain gases in the blood can confirm the type of priapism.
  • Blood tests. Your blood can be tested to measure the number of red blood cells and platelets present. Results might show evidence of diseases, such as sickle cell anemia, other blood disorders or certain cancers.
  • Ultrasound. You might have Doppler ultrasonography, a noninvasive test that can be used to estimate your blood flow through blood vessels by bouncing high-frequency sound waves (ultrasound) off circulating red blood cells. This test can be used to measure blood flow within your penis that would suggest ischemic or nonischemic priapism. The exam might also reveal an injury or abnormality that might be an underlying cause.
  • Toxicology test. Your doctor might order a urine test to screen for drugs that might be the cause of 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.


Excess blood is drained from your penis using a small needle and syringe (aspiration). As part of this procedure, the penis might also be flushed with a saline solution. This treatment often relieves pain, removes oxygen-poor blood and might stop the erection. This treatment might be repeated until the erection ends.


A sympathomimetic medication, such as phenylephrine, might be injected into the penis. This drug constricts blood vessels that carry blood into the penis. This action allows blood vessels that carry blood out of the penis to open up and allow increased blood flow out. This treatment might be repeated several times if needed. You will be monitored for side effects, such as a headache, dizziness and high blood pressure, particularly if you have high blood pressure or heart disease.

Surgical or other procedures

If other treatments aren't successful, a surgeon might perform surgery to reroute blood flow so that blood can move through your penis normally.

If you have sickle cell anemia, you might receive additional treatments that are used to treat disease-related episodes.

Nonischemic Priapism

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

Surgery might be necessary in some cases to insert material, such as an absorbable gel, that temporarily blocks blood flow to your penis. Your body eventually absorbs the material. You might also need surgery to repair arteries or tissue damage resulting from an injury.

Preparing for your appointment

If you have an erection lasting more than four hours, you need emergency care. If you experience recurrent, persistent, partial erections that resolve on their own, see your doctor. Treatment might be needed to prevent further episodes. The doctor might suggest that you make a follow-up appointment with a specialist in sexual medicine, such as a urologist or an andrologist.

Here's some information to help you prepare for your appointment, and what to expect from your doctor.

What you can do

  • Write down symptoms you're experiencing,including any that might seem unrelated.
  • Make a list of all medications, vitamins and supplements that you're taking. Tell your doctor if you're taking any other drugs.

To prepare for your appointment, write down a list of questions to discuss with the doctor. Questions might include:

  • What is likely causing the problem?
  • What kind of tests might be needed?
  • What can be done to prevent this problem in the future?
  • If medication is necessary, is there a generic alternative?
  • Are there activities, such as exercise or sex, that should be avoided? If so, for how long?
  • Does priapism increase the risk of developing erectile dysfunction?
  • Do you have brochures or can you suggest websites that explain more about priapism?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask other questions that occur to you.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them might allow time later to cover other points you want to address. Your doctor might ask:

  • When did your symptoms first start?
  • How long did the erection or erections last?
  • Was the erection painful?
  • Have you had an injury to your genitals or groin?
  • Did the erection occur after using a particular substance, such as alcohol, marijuana, cocaine or other drugs?

Your doctor might order lab tests to determine if a health condition is causing priapism.

What you can do in the meantime

Don't stop taking any prescription medications without consulting your doctor.