Loss of water pressure upstairs after changing shut off valves downstairs?

Question

I changed my shut off valves in my dowstairs half bath. I used compression fittings for both hot and cold water pipes. Now the bathroom upstairs has very little water pressure, actually it's just a trickle. The lines go from the downstairs bath up through the wall and into the upstairs bath. THe toilet and tub work fine. What could I have done to block the water flow to the upstairs? THere was nothing unusual about the installation. Thanks!

Answer 1

I agree with stinky seems like you loosened some calcium or something working downstairs

Answer 2

Did you remove the screen from the faucet and clean it? May be some debris in there from your work downstairs.

Answer 3

Replace the aerator on the upstairs faucet. Its like  2 dollars at any home center or hadware store