Colds and the flu usually bring on dehydration, so drinking water is a crucial part of your recovery. "Juice, broth, lemon water and herbal teas also help,” says Davtyan. But avoid caffeine and alcohol. “They act as a diuretic and increase the degree of dehydration," she says. As unappealing as that glass of water might sound, your body needs it to replenish. So drink up.