It is not good to doubt more than required.I have an uncle who is a little sick these days. His sons make him visit the doctors and all his reports are normal but still, he is not trusting any doctor or report. The family is worried and disturbed due to his behaviour. It is not that he has behaved like this only now, rather he was of such nature from the beginning. He did not trust anyone easily but looked at each one with suspicion. As his age grew, his nature became even more complex. Now the situation is such that he needs the help of a good psychiatrist.
We often take such natures seriously only when it becomes a problem for us. Both, believing everyone too much or keep doubting everyone, can cause problems in life. It is important to take care of such things so that the balance of trust can be made, otherwise, the problem will increase with the age.