In the bathroom sink, I see the hotwater pressure is very good . When I open the cold water it is very low. It is was fine 2 weeks ago.

What could be the problem?

Thanks

Asaad

Some mineral build-up in the pipe let go and your faucet sucked it up and now it's blocking the cold water inlet ports of the cartridge.
The solution would be to shut the water off to the valve and open it up to check and clean the cartridge. If you need further instructions I'll need the brand name of the faucet. Regards, Tom