some confusion with the greater then and less then values

I set up a armor tick and i set the armor to the same as leather so torso health is 80, I set the procedure to detect the if (((itemstack.getItemDamage()) >= 25)) then it it only works when the item breaks witch not sure why. then when i do if (((itemstack.getItemDamage()) <= 25)) it dose nothing. I might have to restart the whole thing I imported this from the last version witch the if (((itemstack.getItemDamage()) >= 25)) work just fine tell I added more code to the procedure. I am starting to wonder if I under stand values or not. I tried taking away equal to and just use the >< but same results.