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Persistent Erection



Geetha Maddukuri

, MD, Saint Louis University

Reviewed/Revised Dec 2022
Topic Resources

Persistent erection (priapism) is a painful, persistent, abnormal erection unaccompanied by sexual desire or excitation. It is most common in boys aged 5 to 10 years and in men aged 20 to 50 years. (See also Overview of Urinary Tract Symptoms Overview of Urinary Tract Symptoms Kidney and urinary tract disorders can involve one or both kidneys, one or both ureters, the bladder, or the urethra, and in men, the prostate, one or both testes, or the epididymis. Problems... read more .)

The penis is composed of three cylindrical spaces (sinuses) of tissue through which blood can flow (called erectile tissue). The larger two sinuses, the corpora cavernosa, occur side by side. The third sinus (the corpus spongiosum) surrounds the urethra and ends as the cone-shaped end of the penis (glans penis). When these sinuses fill with blood, the penis becomes larger and rigid (erect). Muscles then tighten around the veins of the groin, preventing blood from flowing out of the penis and keeping the penis erect.

Did You Know...

  • Erections can last a long time and become painful.

  • A boy or man with a prolonged, painful erection should see a doctor immediately.

Ischemic priapism

Most cases of persistent erection involve failure of blood to flow out of the penis. Blood backs up, preventing new oxygen-rich blood from entering the penis. As a result, the penis can become starved of oxygen. This condition is known as ischemic priapism or low-flow priapism. Severe pain occurs if an erection lasts longer than 4 hours. The penis may be erect while the glans penis may be soft. Prolonged priapism can lead to erectile dysfunction Erectile Dysfunction (ED) Erectile dysfunction (ED) is the inability to attain or sustain an erection satisfactory for sexual intercourse. (See also Overview of Sexual Dysfunction in Men.) Every man occasionally has... read more or even the death of penile tissue.

Stuttering priapism is a recurring form of ischemic priapism in which episodes of erection alternate with periods when the penis is not erect.

Nonischemic priapism

Less commonly, priapism is due to uncontrolled flow of blood into the penis. Such abnormal blood flow usually results from an injury to an artery in the groin area. Nonischemic priapism is also known as high-flow priapism. It is less painful than ischemic priapism and does not lead to tissue death. The penis is erect but not fully rigid. Subsequent erectile dysfunction is much less common than in ischemic priapism.

The Penis and Urethra

Causes of a Persistent Erection

Priapism probably results from abnormalities of blood vessels, red blood cells, or nerves that cause blood to become trapped in the erectile tissue of the penis. Sometimes doctors are not able to determine the cause of priapism.

Common causes

Less common causes

Evaluation of a Persistent Erection

The following information can help people know when to see a doctor and what to expect during the evaluation.

Warning signs

In boys and men with priapism, certain symptoms and characteristics are cause for concern. They include

  • Severe pain

  • Age less than 10 years

  • Recent injury to the penis or groin area

  • Fever and night sweats

When to see a doctor

All boys and men who have priapism should see a doctor immediately for treatment. If warning signs are present, further evaluation may be necessary to determine whether the cause of priapism is something unusual or serious.

What the doctor does

Doctors first ask questions about symptoms and medical history and then do a physical examination. What they find during the history and physical examination often suggests a cause of priapism and the tests that may need to be done (see table Some Causes and Features of Priapism Some Causes and Features of Priapism Some Causes and Features of Priapism ).

Doctors ask

Although doctors focus the physical examination on the genitals to detect signs of injury or cancer, they also examine the abdomen and do a digital rectal examination. Doctors may also do a neurologic examination to look for signs of a spinal cord disorder.



The need for testing depends on what doctors find during the history and physical examination. Often, the type of priapism (ischemic or nonischemic) and cause are obvious, such as the use of a drug to treat erectile dysfunction Erectile Dysfunction (ED) Erectile dysfunction (ED) is the inability to attain or sustain an erection satisfactory for sexual intercourse. (See also Overview of Sexual Dysfunction in Men.) Every man occasionally has... read more . If it is not clear whether priapism is ischemic or nonischemic, doctors may take a sample of blood from the penis to test for the presence of oxygen and other gases (arterial blood gas measurement). They may also do duplex ultrasonography (ultrasonography that measures blood flow and shows structure of the blood vessels through which the blood is flowing). These tests help differentiate ischemic from nonischemic priapism. Ultrasonography may also show the blood flow patterns in priapism and the anatomic abnormalities contributing to priapism. If the cause is still not obvious, doctors test for blood disorders and urinary tract infections Overview of Urinary Tract Infections (UTIs) In healthy people, urine in the bladder is sterile—no bacteria or other infectious organisms are present. The tube that carries urine from the bladder out of the body (urethra) contains no bacteria... read more . Testing includes

Hemoglobin electrophoresis is a blood test to check for abnormal hemoglobin (the protein that carries oxygen in red blood cells) as occurs in sickle cell disease.

Treatment of a Persistent Erection

Simple measures that can be taken immediately include applying ice, climbing stairs, or both. However, priapism is an emergency. Treatment should begin as soon as possible, preferably by a urologist in an emergency department.

Doctors give boys and men who have significant pain a pain killer (analgesic). Other measures are usually needed if priapism is ischemic. After numbing the penis with a local anesthetic, doctors may inject the penis with a drug that causes the blood vessels carrying blood to the penis to narrow (for example, phenylephrine), decreasing blood flow to the penis and causing the swelling to subside. Doctors may also draw blood out of the penis using a needle and syringe (aspiration). Drawing out blood helps reduce pressure and swelling. Sometimes doctors also flush the veins of the penis with a salt water (saline) solution to help remove oxygen-depleted blood or blood clots.

These measures may be repeated. If they are still not effective, doctors may create a surgical shunt. A shunt is a passageway that is surgically inserted into the penis to divert excess blood flow and allow circulation in the penis to return to normal.

Key Points

  • Priapism is an emergency that requires urgent evaluation and treatment.

  • Drugs, including those used to treat erectile dysfunction, and sickle cell disease are the most common causes.

  • Treatment usually involves injecting a drug into the penis and removing the excess blood from it.

Drugs Mentioned In This Article

Generic Name Select Brand Names
LiQrev, Revatio, Viagra
Adcirca, ALYQ, Cialis, Tadliq
Levitra, Staxyn
Caverject, Caverject Impulse, Edex, Muse, Prostin VR
Desyrel, Oleptro
Eskalith, Eskalith CR, Lithobid
4-Way Nasal, Ah-Chew D, AK-Dilate, Anu-Med, Biorphen, Formulation R , Foster & Thrive Nasal Decongestion, Gilchew IR, Hemorrhoidal , IMMPHENTIV, Little Remedies for Noses, Lusonal, Mydfrin, Nasop, Nasop 12, Neofrin, Neo-Synephr, Neo-Synephrine, Neo-Synephrine Cold + Allergy, Neo-Synephrine Extra Strength, Neo-Synephrine Mild, Neo-Synephrine Non-Drowsy Cold + Allergy, Ocu-Phrin, PediaCare Children's Decongestant, PediaCare Decongestant, PediaCare Infants' Decongestant, Sinex Nasal, Sudafed PE, Sudafed PE Children's Nasal Decongestant , Sudafed PE Congestion, Sudafed PE Sinus Congestion, Sudogest PE, Vazculep
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