Rehydrating the body is key in order to tackle a hangover.
Pain killers can help with headaches and muscle cramps. Sugary foods may help you feel better. In some cases, an antacid may be needed to settle your stomach first. Bouillon soup, a thin vegetable-based broth, is a good source of vitamins and minerals, which can top up depleted resources. Its main advantage is it's easy for a fragile stomach to digest.
You can replace lost fluids by drinking bland liquids that are easy on the digestive system, such as water, soda water and isotonic drinks.