Is impotence treatable at the age of 37-years-old?
It depends on the cause of the impotence.
Viagra has many side effects on the body and so only to be taken if erectile dysfunction is present and that too under proper doctor's supervision.
Reasons for erectile dysfunction in elderly include low testosterone with aging, higher incidence of medical conditions causing ED such as hypertension, dyslipidemia, diabetes mellitus, atherosclerotic heart disease.
Yes, anxiety both directly and indirectly in the form of other health conditions (Heart disease, high blood pressure/cholesterol, obesity) can cause erectile dysfunction.