Kevin Grande is right, if your ‘health’ is high enough then your regeneration rate (while asleep) will be faster and you will heal after a few days. ‘health’ is a hidden stat in CataclysmDDA which determines your immunity against ambient diseases like Common-Cold & Influenza, it gradually comes down to 0 if its not increased or decreased. Drugs and Alcohol drastically decrease your ‘health’ so you should avoid them for a while. As far as increasing ‘health’ goes, the only useful source that I’ve found are vitamins. Taking vitamins regularly (2 per day is good enough), should increase your ‘health’. From what I’ve observed, I think if your Health (of any body part) decreases by 1 (i.e. it changes color to light-green or light red instead of the regular dark-green), it takes a long time to heal.
I think its a bug in the latest version 0.B “Brin”. When I was playing in this version, I installed a Power-Storage CBM which I got from a Shocker-Brute, suddenly my Health (all the body parts) decreased by 1 even when the CBM installed successfully and it never healed even after 2-3 days. So I looted all the pharmacies, crafted some bandages and first aid kits and somehow managed to heal myself. Even now (after 5 days from the incident), I’ve not healed completely. I really think its some kind of bug (though I’m not sure of it so I’ve not got it reported) since I’m playing an experimental release. I don’t use much drugs and alcohol, except Aspirin and Codeine, so it cannot be due to low ‘health’ (but there’s a possiblity since ‘health’ is a hidden stat).
But anyway, I think maintaining your health is vital in CataclysmDDA since it protects you from diseases like Common-Cold (and it can also prevent infections from zombie bites!).
Thanks