Need more info.

All faucets?

When did it start?

Had any plumbing work done?

How is cold?

Answer these and any other info u can give us and we can help.

Chuck

Please answer Chuck's questions. If its just the one sink its likely a clogged hot inlet in the mixing valve.

This is a long shot, but... bathroom sink faucets that don't have aerators usually have screens in the fuacet supply ports. These screens are very fine and clog easily. Odds that you have this type of faucet is probably slim, but I just thought Id throw it out there.

MGD think you missed that the OP says only hot is a problem.

Nope, on faucet like the one I posted, the hot and the cold supply ports each have a screen right where you hook the lav supply to. In this case, one or the other may plug up and the other one be just fine.