It may be difficult to know if your cat has a health problem. Cats are experts at hiding illness. In the wild, this instinct can protect them from predators or other animals that might be a threat. Our domesticated cats have the same tendency to hide if they are not feeling well. The behaviour is an instinct of self-protection.
For us, humans, is difficult to move on when we have a heath problem. For cats is much easier to accept the problem and move on. This is the reason why some cats have to be very ill for their sickness to become obvious for their humans.
This is why it is very important for us to notice subtle changes in our cats behavior. If you notice even small changes, always contact your vet and ask for advice.
So what are those subtle changes that might tell us that something can be wrong with our cat?