What does fear do to the body?
Fear causes your body to release hormones so that it can respond, like fight/flight or freeze/faint. It increases cortisol and adrenaline in the body. All good things if it happens on occasion and in response to a real threat.
But many times, this day in age, our body/brains react with a full on fear response when it perceives a threat (and it really isn’t a threat since we don’t live in caveman times) and your body is thrown into this automated response. Over time, you may have a chronic fear/stress response and that can take a toll on your memory, mental health, physical well-being and much more.
So if you are constantly having fear responses, anxiety, etc. I would take care of it before it begins to have long term damaging effects on your brain and body.