A cat may suddenly become more aggressive for a variety of reasons. Here are some possible causes: 1. Physical issues: Cats may be experiencing pain, discomfort, or illness, which may cause them to behave abnormally. 2. Stress response: The cat may be under some form of stimulation or pressure, such as fighting with other cats, changes in family members, changes in the environment, etc. These may cause the cat to have a stress response and then show aggressive behavior. .

3. Behavioral problems: Some cats may have behavioral problems, such as being overly dependent on humans and being too aggressive towards humans. These issues may cause cats to behave aggressively in certain situations.

4. Diseases: Certain diseases, such as hyperthyroidism, epilepsy, abscesses, arthritis, dental disease, rabies, trauma, as well as sensory decline or cognitive dysfunction in older cats, may cause Causing increased aggression in cats.