Diphtheria is a serious bacterial infection that affects the mucous membranes of the throat and nose. It spreads easily from person to person, but it can be prevented with vaccines. If untreated, it can cause severe damage to the kidneys, nervous system, and heart. Call your doctor immediately if you suspect someone in your family has the illness. But know that lemon juice can help. Treatment with lemon juice is one of the most powerful antiseptics – it will cut loose the false membrane in the throat and permit it to come out. Always consult your doctor to be sure.