Priapism: Definition, Treatments, Causes & More

If you had to play a word association game with “erections” as a prompt, chances are, descriptors like “long,” “strong” and “enjoyable” wouldn’t be too far from your reasoning. 

And that’s understandable. What’s not to love about erections?

But just how long is too long? An erection is considered prolonged when it persists for longer than four hours, at which point it is no longer caused by sexual or psychological stimulation, but is instead, a medical emergency.

Should you experience this, it is important to identify and take the appropriate steps when a prolonged erection, referred to as “priapism,” occurs. 

What is Priapism? Definition & Symptoms

Priapism is a prolonged and often painful erection, usually occurring beyond or without any sexual or mental stimulation. While it is relatively uncommon, it is an important phenomenon to be aware of because prolonged erections can lead to tissue damage and erectile dysfunction. 

Any erection that lasts longer than four hours is deemed an emergency and must receive immediate medical attention.

While priapism can occur in all age groups (including newborns), it usually affects males between the ages of five to 10 years old and 20 to 50 years old.

There are two main types of priapism — ischemic and nonischemic. 

Ischemic — or low-flow — priapism occurs when blood is unable to leave the penis. It is the more commonly occuring form of priapism. It results in painful and prolonged erections where the penile shaft is rigid, but the tip of the penis remains soft.

Ischemic priapism can become recurrent or stuttering following repeated incidents of prolonged erections. These recurrent episodes typically last under four hours, but could increase in frequency and duration.

High-flow or nonischemic priapism, however, is a rare form of priapism that occurs when blood flow to the penis isn't properly regulated. It is commonly due to an injury to the penis which may rupture an artery, preventing the normal flow of blood in the organ. It is usually painless.

Causes of Priapism

It might not seem like it, but an erection is a delicate process that requires the collaborative efforts of the muscular, nervous and notably the circulatory systems. Erections are typically in response to sexual stimulation. 

To produce one, the brain sends messages to the blood vessels in the penis when arousal occurs. 

This causes the arteries to open up, allowing increased blood flow to the penis while the veins simultaneously close up to trap the inflow. 

When the penis is filled with blood, it becomes erect, eventually losing this hardness and returning to its flaccid state after the blood flows out.

In the event that this normal flow of blood is disrupted, an erection can persist for a prolonged period. This may be for a number of reasons:

  • Blood disorders: Hematological disorders like sickle cell anemia and leukemia are known causes of priapism.

    Sickle cell anemia is an especially common cause of prolonged erections, with scientists believing at least 42 percent of adult men with the condition will experience priapism.

    This is due to the red blood cells becoming hard and sticky, changing shape from round to a C-shape (known as sickling).

    This disrupts the flow of blood into the penis. These sickled red blood cells stick together, block blood vessels and slow the movement of oxygen to the penis. Additionally, these sickle cells don’t live as long as the normal red blood cells, causing a shortage of cells to carry oxygen to tissue.

    Priapism in leukemia is thought to be caused by the body’s abnormal production of white blood cells, which can cause blood to thicken and clog the veins of the penis, preventing the outward flow of blood from the penis and a retained erection.

    At an incidence rate of around five percent in adult men, leukemia-related priapism is relatively uncommon.

  • Medications: Drug-induced incidents make up about 15 percent to 41 percent of all cases of priapism, with antipsychotic drugs being the most implicated priapism-inducing class of drugs.

    Prolonged erections can arise as a known side-effect of certain medications, some of which include: anticoagulants, antihypertensives, antidepressants, blockers, drugs administered directly to the penis, as well as recreational drugs like marijuana, cocaine and ethanol.

  • Penile Injuries: These are a common cause of the not very common nonischemic priapism.

    These injuries cause trauma to the penis, pelvis or the perineum, leading the artery within the penile structure to rupture and pump a steady, pain-free stream of blood out of the artery and into the penile tissue.

In addition to blood disorders, medications and penile trauma, priapism may also be caused by metabolic disorders like gout, diabetes and renal failure. 

Likewise, it may also be cause by neurogenic disorders such as spinal cord injuries and, in other cases, cancers involving the penis, otherwise known as malignant priapism.

Diagnosing Priapism

While ischemic and nonischemic priapisms are characterised by prolonged erections, they are distinct in causes and treatments, making their accurate diagnosis incredibly important. 

The following are the usual standards of care when diagnosing priapism:

Medical History and Exam: A healthcare provider will ask questions ranging from drug history and the presence of pain, to whether the patient suffers from sickle cell anaemia, length of the erection and if there are any penile injuries.

The physical examination will also involve the healthcare professional examining the genitalia.

They will inspect the penis and groin for any signs of trauma or cancers. By examining the hardness of the penis and if any pain is involved, a specialist is usually able to determine if high- or low-flow priapism is at play.

Diagnostic Tests: These offer a measure of accuracy in determining the type of priapism. They include:

  • Ultrasounds: Which can be used to determine the flow of blood within the penis. Through these tests, it can be determined whether the priapism is low-flow or high-flow.

  • Blood gas measurement: This is an invasive procedure requiring the insertion of a tiny needle into the penis to remove a sample of blood. The state of the blood removed will determine the type of priapism. Where it is black, it is usually indicative of ischemic priapism, as the blood has been deprived of oxygen. Where bright red, it is more likely to be nonischemic priapism.

  • Blood tests: These can be used to show evidence of diseases like sickle cell anaemia and leukaemia.

Where it is suspected that drugs — especially recreational drugs — are at the cause of priapism, a urine toxicology test can also be carried out.

How to Treat Priapism. 

This depends on whether ischemic or nonischemic priapism is in question. 

To understand the urgency of treating ischemic priapism, here’s what happens to the penis when an erection lasts beyond four hours: the blood trapped inside the shaft becomes deprived of oxygen, which in turn causes penile tissue to become deprived of oxygen. 

This can lead to tissue damage, scarring or destruction. Studies show ischemic priapism lasting longer than 24 hours increases the chances of erectile dysfunction by 90 percent.

To treat it, the following options can be used:

Treating priapism, particularly ischemic priapism, is something that must be done urgently in order to prevent the condition from having lasting damaging effects on the penile tissue.

Healthcare professionals employ several methods of treatment, usually from least invasive to most invasive, depending on what works and what doesn’t. 

To get a prolonged erection down, conservative approaches can be attempted first, where appropriate. These include ejaculation — a no-brainer first-call in getting an erection down.

Alternatively, physical exercise and cold showers can be used to stimulate smooth muscles in the penis to stretch, contract and relax to allow blood flow out of the penis and induce detumescence.

Where the erection persists, more invasive approaches need to be adopted to treat ischemic priapism. These include:

Using a needle and a syringe, a healthcare professional may drain the excess, deoxygenated blood in the penis through a process called aspiration.

Another method is injecting medication into the penis. These medications will shrink blood vessels carrying blood into the penis and expand vessels carrying blood out of the penis, allowing for increased blood flow and the reduction of the erection.

Where these measures fail, surgery can be performed to correct the abnormal blood flow in the penis.

For priapism due to underlying conditions like sickle cell disease, the already mentioned treatments may suffice to treat ischemic priapism.

Patients with sickle cell disease also benefit from hydration and oxygenation to reduce the chance of blood cells sickling even more.

If none of these strategies work, then blood transfusions or exchange transfusions may be necessary, but these are not often employed due to potential side effects .

Nonischemic priapism, on the other hand, does not require complicated therapies to be treated, especially because it is largely painless and not a surgical emergency.

Usually, it goes away on its own, but ice packs can be placed over the erection to coerce its reduction. If these conservative measures do not work, then more invasive procedures — including surgery — may be necessary.

In Closing

Here's what you should know: erections? ⁠Great. Prolonged erections? Not so much. 

While we wouldn't suggest keeping a timer on you to measure the length of your erections, being attentive to changes in your body is always a great look out. 

Upon noticing an erection that lasts around or longer than four hours after sexual stimulation or without it — especially if it hurts⁠ — you must consider that prolonged erection an emergency and head to the nearest hospital for immediate treatment.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.