In the study, Selvin's team collected data on more than 2,100 men who participated in the National Health and Nutrition Examination Survey. Men who said they were "sometimes able" or "never able" to achieve and keep an erection were classified as having erectile dysfunction, while men who said they were "always or almost always able" or "usually able" were not. By changing lifestyle and treating underlying heart disease and diabetes, you can decrease the chances of developing erectile dysfunction, Sadeghi-Nejad said. "Erectile dysfunction is not a mandatory side effect of aging," he said. "Don't think of it as a normal process of aging." Causes of Erectile Dysfunction: - Best Canadian Online Pharmacy where you can buy viagra canadian pharmacy viagra for sale canadian pharmacy no prescription buy cheap cialis Diabetes: Diabetes can cause nerve and artery damage that can make achieving an erection difficult. Between 35% and 50% of men with diabetes experience ED, according the National Institutes of Health. Some estimates are higher, stating that up to 75% of men with diabetes will experience at least some degree of ED during their lifetime and the risk increases with age.