I am 50 yars old. Since last fortnight I am unable to get Erection required for successful intercourse. It has happened all of a sudden. I don't have any major health problem. What could be the reason?

Any number of reasons, all of which should be discussed with your own medical practitioner.

Infection you are not aware of, prostrate issues not known. Hormone level getting lower due to age. Kidney issues. I could keep listing.

It is not uncommon at 50 to once in a while have a failure at erection. So a complete exam by your doctor is needed to see or find a problem

Infection you are not aware of, prostrate issues not known. hormone level getting lower due to age. Kidney issues. I could keep listing.

it is not uncommon at 50 to once in a while have a failure at erection. So a complete exam by your doctor is needed to see or find a problem

It isn't uncommon to have a failure at erection at ANY age.

At 50 it is more common