Diphtheria is caused by a bacterial infection that typically affects the mucous membranes in the nose and throat. Diphtheria is spread through airborne droplets, such as a cough or sneeze from an infected person. It is easily spread, particularly in crowded spaces. It can also be spread by touch, through the handling of contaminated objects such as tissues or towels, or by touching an infected wound. Thanks to widespread vaccinations against diphtheria, it has been pretty much eradicated in the United States and other developed countries, with cases being very rare. While it can be treated with medications, it can be very deadly, particularly in children. If contracted and left untreated, in advanced stages diphtheria can cause damage to your kidneys, heart and nervous system. Like any illness, diphtheria can present itself differently from one infected individual to the next. Symptoms of diphtheria can include a thick, grey membrane on the throat and tonsils, sore throat and hoarse voice, swollen neck glands, difficulty or rapid breathing, nasal discharge, fever and chills, and malaise. In others, there may be only a minor illness or no symptoms or signs of illness at all. Individuals who are infected with diphtheria can spread the illness to other people, regardless of if they have symptoms or not. Diphtheria can also form on the skin, although this is more common in tropical climates. In the US it is typically found on people living in crowded, unclean spaces where poor hygiene is a common problem. On the skin, diphtheria shows up through redness and swelling that are similar to bacterial skin infections, as well as pain. Affected individuals may also experience ulcers on their skin that are covered by a gray membrane.