Sounds very simple indeed..
Could you explain what fall damage is in your opinion?
Well, with fall damage I mean that if there is X distance from one place to another, the player doesnt take damage, and if there is B distance, it does take damage, for example, if the player falls from 500 pixels, he doesnt take damage, if he falls from 1000 pixels, he does. Now that I think about it, instead of that, can I make a variable to check how much time the player stays on the air and then for example if he is 3 seconds on the air, subtract 3 from health, and if he is 7 seconds, subtract 7 from health?