| Psycho-social Issues |
Performance anxiety |
| Sexual attitudes |
| Social upbringing and cultural issues |
| Relationship problems |
| Employment and financial stress |
| Depression |
| Psychiatric disorders |
| Physical (metabolic) problems |
Diabetes |
| High blood pressure |
| High cholesterol |
| Obesity |
| Liver failure |
| Renal failure |
| Endocrine disorders |
Over- or under-active thyroid |
| Low testosterone |
| High prolactin |
| Vascular disorder |
Atherosclerosis |
| Substance abuse and medications |
Cigarettes |
| Alcohol and substance abuse |
| Medication for high blood pressure, high cholesterol, depression, psychiatric disorders, prostate cancer |
| Neurological disorders |
Spinal cord injury |
| Alzheimer’s disease |
| Parkinson’s disease |
| Multiple sclerosis |
| Diabetic neuropathy |
| Pelvic surgery (Prostate, bowel) |
| Urological disorders |
Peyronie’s disease |
| Pelvic injury |