Our blood requires oxygen for various processes in our body and oxygen supply is managed by the lungs. When we breathe in air, dust and debris also settle in, blocking the airways. Also, the air inhaled should be moist. For this purpose, the lining of the lungs continually produces mucus. Looking after the chest and keeping the lungs clear is extremely important to prevent infection in the lungs. If the sputum is not cleared regularly, then the lungs start to work below its capacity and we get less supply of oxygen. Very often this phenomenon is termed as restrictive lung disease which restricts lung expansion, resulting in decreased lung volume, leading to inadequate oxygenation of the blood (blood carrying less oxygen). Any infection or inflammation can block the airways, making breathing difficult, leading to a life threatening disease known as cystic fibrosis. To avoid such problems, mucus should be expelled from the lungs. Lung infections and diseases can easily spread from one person to another. Personal hygiene e.g. Washing hands, covering your nose and mouth when coughing and sneezing and disposing of tissues and sputum pots in appropriate waste bins, should be maintained to prevent cross infection.