- At rest, a person breathes about 14 to 16 times per minute. After exercise it could increase to over 60 times per minute.
- New babies at rest breathe between 40 and 50 times per minute. By age five it decreases to around 25 times per minute.
- The total surface area of the alveoli (tiny air sacs in the lungs) is the size of a tennis court.
- The lungs are the only organ in the body that can float on water.
- The lungs produce a detergent-like substance (surfactant) which reduces the surface tension of the fluid lining, allowing air in.
Among the most common symptoms of lung disorders are cough, shortness of breath (dyspnea), and wheezing. Less commonly, a blockage in the airways between the mouth and lungs results in a gasping sound when breathing (stridor). Problems in the lungs can also lead to coughing up of blood (hemoptysis), a bluish discoloration of the skin due to a lack of oxygen in the blood (cyanosis), or chest pain. Prolonged lung disease can even produce changes in other parts of the body, including finger clubbing. Some of these symptoms do not always indicate a respiratory problem. Chest pain, for example, may also result from a heart or gastrointestinal disorder, and shortness of breath can be caused by a heart or blood problem. The lungs are a pair of organs in the chest which are primarily responsible for the exchange of oxygen and carbon dioxide between the air we breathe and the blood.