Many cold and flu viruses first enter through the nose. With every breath we take, tiny airborne viruses can land inside our nasal passages, which act like a main "doorway" into the body. Essential oils are one of the best ways to help stop these germs before they take hold. They can boost your immune system, reduce your chances of getting sick, and even help you feel better faster if a cold or flu does sneak in. How Aromatherapy Can Help Essential oils are concentrated plant