Some of the symptoms of stress in a cat is spraying (even if neutered), inappropriate elimination, loss of appetite, trembling, excessive meowing and hiding. I would also say shedding is part of a cat being stressed.
Stressed out cats often over groom themselves to the point of losing fur. They may also stop using a litterbox. They may meow and follow you around the house. They may stop eating or drinking. They may lose weight. In extreme cases they may even become ill. If possible, avoid this by making changes slowly.
A cat that is stressed will sometimes mark their territory by spraying, they will also cry alot. A couple of good products to help deal with stressed cats are feliway or pet ease. You can get these products at a pet store or find them on the internet.
