Mother cats and their kittens both purr when the kitten is suckling their mother's milk. However, purring is not simply a sign of contentment. Cats also purr when injured, afraid or lonely and even when giving birth.
Depending on the mood of your furry friend the sound of their purr can range from a high pitched trill to a low rumble.A cat's purr can also possess great healing powers for the elderly or sick. Many hospitals and retirement homes bring in cats to sit with their patients to aid in the healing process. It is widely accepted that cat owners possess lower blood pressure. This may be because there is nothing in this world that compares to cuddling a friendly feline and feeling the smooth vibrations against your chest.