@bereese From what I have read, medical experts speculate the symptoms may stem from autonomic nervous system dysfunction, nerve damage, or central sensitization where the brain becomes overly reactive to stimuli...and over 30% of long covid patients have the "vibration". I sense the "vibration" as "heart palpitations". Although no standardized cure exists, some clinicians have reported success using low-dose naltrexone (LDN) to reduce inflammation and alleviate discomfort.