• A painful and harmful medical condition in which the erect penis doesn't return to its flaccid state, despite the absence of both physical and psychological stimulation, within four hours.
  Human Phenotype Ontology (HPO)
  The Human Phenotype Ontology Project, 2025
• A prolonged painful erection that may lasts hours and is not associated with sexual activity. It is seen in patients with SICKLE CELL ANEMIA, advanced malignancy, spinal trauma; and certain drug treatments.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• An erection that lasts longer than three hours. Emergency medical treatment is required to prevent permanent damage to the penis.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• Persistent and usually painful erection that lasts for at least four hours in the absence of physical or psychological stimulation, which can be caused by hematologic disorders, including sickle cell disease and leukemia, spinal cord injuries, and medications.
  NCI
  U.S. National Cancer Institute, 2021
• Priapism is 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.
  Merck Manuals
  Merck & Co., Inc., 2025
• Priapism is defined as an abnormal persistent erection of the penis. It is usually painful and it is unrelated to sexual stimulation and unrelieved by ejaculation.
  Medscape
  WebMD, 2025
• 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.
  Mayo Clinic
  Mayo Foundation for Medical Education and Research, 2025
• Priapism is defined as a prolonged and persistent penile erection lasting >4 hours, unassociated with sexual interest or stimulation. It is a true medical emergency with complications potentially resulting in permanent erectile dysfunction. In stuttering or recurrent priapism, individual priapic episodes may last <4 hours.
  Epocrates
  Athenahealth, Inc., 2019
• Priapism, a persistent, painful erection of the penis unaccompanied by sexual excitation or desire. When normal erection occurs, the sides and the bottom of the penis, the corpora cavernosa and the corpus spongiosum, respectively, become engorged with blood so that the penis enlarges, hardens, and...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025