Smoking is one of the most common forms of recreational drug use. Tobacco smoking is the most popular form and beingis practiced by over one billion people globally. Smoking generally has negative health effects. FirstFirstly, smoke inhalation inherently poses challenges to various physiologic processes such as respiration. Smoking damages the airways and air sacs (known as alveoli) in the lungs. Often, lung disease caused by smoking can take years to become noticeable, this means it is often not diagnosed until it is quite advanced. SecondSecondly, smoking narrows the arteries, making it harder for blood to flow, and increasing blood pressure and heart rate. Also, chemicals in tobacco smoke increase the chance of heart problems and cardiovascular diseases. Finally, the immune system protects the body against infection and disease. Smoking compromises this and can lead to autoimmune diseases, such as rheumatoid arthritis. In conclusion, quitting smoking can cut your risk of health problems. The earlier you quit, the greater chance to survive.