Impotence is about.

As not long erection keeping, or absences she is as in nerve exhaustion, obesity, hypertension, diabetes, alchokolism, narcomania, after injuries of spine and head brain, tumor, epilepsy, or Parkinson, hormonal disorders, atherosclerosis, where vessels are closed in blood current penetrating to the penis, as in porostatitis, urethritis, eggs damages, urinary bladder, anti depressants, tranquilizers, over tiredness, lowering secretions and anti hypertensive, as if reasons are found,thus cure theirs.
As within a half year if erection absences,thus visit a doctor, where checking tests on testorone in the blood, ultrasound prostate, test on urinary ways infections.

If reason are psychological, doctor will advice right regime for work, rest, avoid alchokol, smoke, add diet, but these remedies are effecting on erection by using in prescription as alprostadil, caverdgect, in cavering injection in penis, or in urinary canal.