Stress impacts our health in many ways. Stress can cause rapid thinning of hair, which is very true in my case. Cortisol, a hormone brought on by stress, is responsible for hair loss. When we are stressed, our body goes into fight and flight mode. Adrenaline and cortisol, among other stress hormones, are released by our nervous system in response to threats, helping our body deal with them. Our heart beats faster, blood pressure rises, and senses become sharper. These physiological changes are present to help us focus and improve our strength, reaction time, and endurance, preparing us to either fight or flee from the danger at hand. Moreover, during fight-or-flight response, blood and nutrients flow to the body's most vital parts — our bodies divert blood to life-supporting organs and muscles. This keeps us alive and prepares us to fight or flee from whatever is stressing us out. Since we do not need our hair for survival, hair loss or thinning happens.
Reference:
https://www.thehairfuel.com/stress-hair-loss-and-hair-growth/