The two lungs located in the chest are spongy organs that are divided into sections called nodes. The Mayo Clinic calls the lungs a complicated system of airways that are utilized with every breath. The two major airways, called the bronchi, are subdivided into a million tiny airways that lead to the alveoli, or air sacs, and move the oxygen through the bloodstream and release carbon dioxide. In healthy lungs, the flow of air is unimpeded, allowing the lungs to expand with each inhalation and collapse as air is expelled.
Breathing Easy
Breathing freely is one of the most obvious signs of healthy lungs. The National Heart Lung and Blood Institute reports that signs of healthy lungs, free of chronic obstructive pulmonary disease, or COPD, move freely without any coughing or struggle. Healthy lungs are quiet because there is not a buildup of mucus found in COPD and asthma patients. Mucus causes a wheezing sound that is not present in healthy lungs. Breathing is deep and full with no shortness of breath. The chest expands fully when healthy lungs fill with air, unlike COPD-damaged lungs that often have a tight feeling in the chest. Breathing with healthy lungs is a non-stressful even when the lungs are taxed while performing strenuous activities. People with healthy lungs can hold a moderate conversation while running.
Elasticity
The airways and sacs in healthy lungs are very elastic and expand and contract quickly, responding to the flow of oxygen. The sacs fill up like small balloons and deflate just as rapidly. The walls between the various sacs and airway walls are wide open and free of any blockage. Airway passages often are collapsed and closed in people with conditions such as bronchitis or emphysema. Healthy lungs do not produce an overabundance of mucus that must be coughed up.
No Spots
Healthy lungs do not have any unusual spots or clots in them. Blood clots in the lungs are usually formed as a result of medications and other diseases. On X-rays of healthy lungs, there are no spots or shadows that could be due to cancerous tumors. Healthy lungs are pink and clear, unlike the black lungs often seen in X-rays and autopsies of smokers' lungs or those exposed to radon or other harmful inhalants for a long period of time. Healthy lungs are free from infection and bacteria, unlike lungs infected with pneumonia-causing bacteria.
