Low hot and cold water pressure in shower/tub and sink not as bad in the rest of the house cold water pressure good in the rest of the house old house no basement

How old are the pipes? Do you have a well or water main? Is the tub and sink on the second or higher floor? More details could help pin point the problem.

How old are the pipes? Do you have a well or water main? Is the tub and sink on the second or higher floor? More details could help pin point the problem.

It's a water main'its a one floor house, I put new bath and shower fixtures on and changed a pipe all related to the bathroom ,house is old mostly galvanized pipe

It could be a partial clog somewhere, every once and a while do you get discolored water?

Look for valves that could be not turned on all the way.