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.
All of these factors can lead to stress: 1  Fear and uncertainty. When you regularly hear about the threat of terrorist attacks, global warming, and toxic chemicals on the news, it can cause you to feel stressed, especially because you feel like you have no control over those events. 2  Attitudes and perceptions.