Source: drjohnhong .
erectile dysfunction is more recognized probably because of Viagra and the other ED medicines -- and their huge ad campaigns. In 1994 the Massachusetts Male Aging Study found male sexual dysfunction begins 40 years of age and worsens each decade of life. 40 year old men: 40% some level of dysfunction and 10% had declining libido. Sexual dysfunction includes ED, decreased libido, less satisfaction with sex or orgasm, or abnormal ejaculation. ED worsens by age 50. One study showed 47% of men 55 or older had ED.