"Damage from tobacco smoke is immediate. The chemicals in tobacco smoke reach your lungs quickly every time you inhale, and your blood then carries the toxins to every organ in your body. These chemicals and toxicants damage DNA, which can lead to cancer. Nearly one-third of all cancer deaths every year are directly linked to smoking, and smoking causes about 85% of lung cancers in the United States. Exposure to tobacco smoke quickly damages blood vessels throughout the body and makes blood more likely to clot. This damage can cause heart attacks, strokes, and even sudden death. The chemicals in tobacco smoke inflame the delicate lining of the lungs and can cause permanent damage that reduces the ability of the lungs to exchange air efficiently and leads to chronic obstructive pulmonary disease, including emphysema and chronic bronchitis. Smoking longer means more damage. Both the risk and the severity of many diseases caused by smoking are directly related to how long the smoker has smoked and the number of cigarettes smoked per day. Chemicals in tobacco smoke cause inflammation and cell damage and can weaken the immune system. White blood cell counts stay high while smoking continues, meaning the body is constantly fighting against the damage caused by smoking, which can lead to disease in almost any part of the body. Smoking can cause cancer and weaken the body’s ability to fight cancer. With any cancer, even those not related to tobacco use, smoking can decrease the benefits of chemotherapy and other cancer treatments. Exposure to tobacco smoke can help tumors grow. The chemicals in tobacco smoke also complicate the regulation of blood sugar levels, exacerbating the health issues resulting from diabetes. Smokers with diabetes have a higher risk of heart and kidney disease, amputation, eye disease causing blindness, nerve damage, and poor circulation. Poisons in smoke pose a danger right away. Sudden blood clots, heart attacks, and strokes can be triggered by tobacco smoke. Even smoking a cigarette now and then is enough to hurt you, and sitting in a smoky bar raises your odds of a heart attack."