Cats purring and rubbing against people may be due to the following four reasons:

1. Showing goodwill: It may be because the cat likes its owner and expresses its affection to the owner.

2. Acting coquettishly: The cat may be hungry, so it uses coquettish behavior to attract the owner's attention and beg for food.

3. In estrus: When a cat is in estrus, it will become clingy and will use its body to rub against its owner, and will always follow the owner.

4. Disease: If the cat purrs continuously, it may be due to respiratory infection virus. At this time, it should be taken to the animal hospital for further examination and confirmation.