Here is a list of possible causes:

Medications…

…for Anti-anxiety, Antidepressants, Antihistamines, Blood Pressure, Cholesterol, NSAIDS (nonsteroidal anti-inflammatory drugs) are all notorious offenders:

  • deal with the root of your issues and replace drugs with diet and therapy

Periodonditis

…is a type of prolongued inflammation of the gums that causes damage to blood vessels which can lead to impotence:

  • maintaining gum health by brushing, flossing and regular professional cleaning can improve ED in 3 months

Salt

…causes a reduction in endothelial nitric oxide in blood vessels causing a restriction of blood flow to the penis:

  • cut back on salt by avoiding processed foods and include potassium-rich foods like spinach, yogurt, avocado, sweet potato & bananas

Sleep Apnea:

Decreased oxygen levels chronically affects the vasculature of the penis while lack of REM (rapid eye movement) sleep interferes with testosterone production

  • lose excess weight to decrease symptoms and possibly eliminate the sleep apnea

Smoking:

75% of those who quit achieved firmer, faster erections and reached arousal 5 times faster than smokers