Implemented medical side-effects.

code/modules/mob/living/carbon/human/life.dm

@@ -99,6 +99,8 @@ var/const/BLOOD_VOLUME_SURVIVE = 122
 
 	handle_pain()
 
+	handle_medical_side_effects()
+
 	//Status updates, death etc.
 	handle_regular_status_updates()		//TODO: optimise ~Carn
 	update_canmove()

code/modules/reagents/Chemistry-Reagents.dm

@@ -1501,6 +1501,7 @@ datum
 					return
 				if(!M) M = holder.my_atom
 				M.heal_organ_damage(2*REM,0)
+				M.add_side_effect("Headache")
 				..()
 				return