Your health slowly regenerates out of combat as well, and anything you can break or defeat has a chance of dropping food items that will help restore your health. You will notice bread, meat, sausages, hamburgers, and even haggis (yuck!) appear. Walking over these food items will restore your Hero's health.
Want more food? Play as, or travel with, a Battle Chef! Battle Chefs can cook food on the fly, and they also create food randomly when fighting. Their Dungeon Buster, called Meateors, rains exploding cows that turn into healing hamburgers on impact.
You can also use a Health Shot (gifted from friends) or Health Potion (found in Item Boxes or in Daily Reward Mystery Boxes) while in a dungeon, if you have equipped it before entering.
Some characters, like Rangers and Sorcerers, can also equip healing scrolls which can be purchased in the Shop as early as level 4 or found in the dungeons.
Healing scrolls will heal everyone (including pets) within a short distance of the person using the scroll.