Thyroid disease in cats is linked to heart disease and a fast heartbeat in conjunction with any other symptoms of thyroid problems is cause for a trip to the vet. Once the hyperthyroidism is treated, your cat's heart rate should return to normal.
Stress reaction â some studies have found that paranoia is more common in people who have experienced severe and ongoing stress â for example, prisoners of war. How stress can trigger paranoia is unclear.
The dangers of stress. While the jury may still be out on whether prolonged stress can damage the heart, we do know that stress can cause upsetting symptoms such as anxiety, insomnia, irritability and low self-esteem. It can also lead to unhealthy coping mechanisms such as drinking, overeating and drug use.