Why is my cat suddenly peeing outside the litter box?

Sudden changes in litter box habits (especially when a cat uses the box for one function but not the other) are almost always worth investigating medically first. A urinary tract infection, bladder inflammation, or early kidney changes can make urination painful, and the cat begins to associate the box with that pain. The box itself is not the problem, but it becomes the place where something hurt. Rule out medical causes with a vet visit before making any environmental changes. If the vet gives a clean bill of health, the next step is reviewing the box setup: location, size, litter type, and how often it is cleaned. A cat avoiding liquids but not solids often points to a surface or texture preference that developed alongside the medical episode, even after the physical cause is resolved.