Call your vet and describe your cat's symptoms with any of your concerns about the cat's well-being. Your veterinarian may discover changes in your cat's health that you have overlooked. It is always better to err on the side of caution. There are many reasons that cats can develop such fears. There may have been limited exposure to people and other animals when the cat was young.
Socialization is an important aspect of raising a kitten.
Without adequate, continuous and positive interactions with people and other animals, cats may develop fears. Because the socialization period in cats begins and ends earlier than it does in dogs, the early environment of the kitten is most important. This learning may then generalize to similar situations. For example, a bad experience with a small child could result in a cat that is fearful of all small children. Genetics is another important contributing factor to the development of fear.