Lungs

The lungs are two spongy organs located inside the chest on either side of the heart. Their main function is to exchange gases between the air and the blood. When we inhale, air travels through the nose or mouth, passes down the trachea and bronchi, and reaches millions of tiny air sacs called alveoli.

Their thin walls are surrounded by small blood vessels, allowing oxygen to pass into the bloodstream while carbon dioxide moves from the blood into the air to be exhaled. The diaphragm, a broad muscle beneath the lungs, contracts and relaxes to help draw air in and push it out. The right lung is slightly larger than the left because the heart occupies part of the left side of the chest.

Healthy lungs supply oxygen to every cell in the body, making energy production possible while removing carbon dioxide, a waste product of metabolism. They also help regulate the body's acid-base balance and protect against harmful particles and microorganisms through mucus, tiny hair-like structures called cilia, and immune cells.

Regular physical activity improves breathing efficiency, while avoiding tobacco smoke and reducing exposure to air pollution help preserve lung function. Vaccination against certain respiratory infections can also lower the risk of serious illness. Doctors assess lung health with physical examinations and tests such as spirometry, chest X-rays or computed tomography scans, depending on the condition being investigated.