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.
Here are some other specific examples of paranoia: 1  Loathing or hatred of activities you or normal people would usually feel comfortable in, such as parties, large crowds, and the mall.  Excessive worry about what people think about you, or that they are laughing about or whispering about you behind your back.