How can an anxiety disorder cause the adrenal glands to affect the body?

More adrenalin: If anxiety is acute enough, the sympathetic nervous system can be activated, causing Adrenalin to be pumped into the patient's system. Witness what happens in extreme cases of, let's say a car falling on someone and someone nearby able to lift the car off the person. That seemingly superhuman strength is caused by Adrenalin triggered by catastrophic anxiety, not to mention empathy!

Anxiety & fear: Trigger the fight/flight reaction to a perceived threat. The brain signals the adrenal glands to release Adrenalin as part of that reaction. Fight/flight includes muscle tension, cold hands & feet, increased heart rate, rapid & shallow breathing, stomach upset, headaches, dry mouth, increased sweating, mind racing, & insomnia.