The respiratory system is the network of organs and tissues that help you breathe. It includes your airways, lungs and blood vessels. The muscles that power your lungs are also part of the respiratory system. These parts workt ogether to move oxygen throughout the body and clean out waste gases like carbon dioxide. The respiratory system has many functions. Besides helping you inhale (breathe in) and exhale (breathe out), it allows you to talk and to smell. Warms air to match your body temperature and moisturises it to the humidity level your body needs. Delivers oxygen to the cells in your body. Removes waste gases, including carbon dioxide, from the body when you exhale. Protects your airways from harmful substances and irritants. Many conditions can affect the organs and tissues that make up the respiratory system. Some develop due to irritants you breathe in from the air, including viruses or bacteria that cause infection. Others occur as a result of disease or getting older. Conditions that can cause inflammation (swelling, irritation and pain) or otherwise affect the respiratory system include: Allergies: Inhaling proteins, such as dust, mild, and pollen, can cause respiratory allergies in some people. These proteins can cause inflammation in your airways. Asthma: A chronic (long-term) disorder, asthma causes inflammation in the airways that can make breathing difficult. Infection: Infections can lead to pneumonia (inflammation of the lungs) or bronchitis (inflammation of the bronchial tubes). Common respiratory Infections include the flu (influenza) or a cold. Disease: Respiratory disorders include lung cancer and Chronic Obstructive Pulmonary Disease (COPD). These illnesses can harm the respiratory systemâ??s ability to deliver oxygen throughout the body and filter out waste gases. Aging lung capacity decreases as you get older. Damage: Damage to the respiratory system can cause breathing problems.