• Diabetes Mellitus
• Hypertension (also known as High Blood Pressure)
• Atherosclerosis
• Kidney Failure
• Heart Disease
• Neurological Disorders such as Multiple Sclerosis, Parkinson’s Disease, Stroke, Paraplegia, or Spinal Cord Lesions
• Pelvic or Perineal Injuries
• Gradual Injuries, as in bicycle-riders
• Surgery on areas such as Bowel, Rectum, Bladder, Spine, Prostate, Urethra
• Local Problem such as Peyronie’s Disease
• Some Prescribed Medications