The lungs are a pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles), finally becoming microscopic.
The bronchioles eventually end in clusters of microscopic air sacs called alveoli. In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled. Between the alveoli is a thin layer of cells called the interstitium, which contains blood vessels and cells that help support the alveoli.
The lungs are covered by a thin tissue layer called the pleura. The same kind of thin tissue lines the inside of the chest cavity — also called pleura. A thin layer of fluid acts as a lubricant allowing the lungs to slip smoothly as they expand and contract with each breath.
Overview
A cancer that begins in the lungs and most often occurs in people who smoke.
Two major types of lung cancer are non-small cell lung cancer and small cell lung cancer. Causes of lung cancer include smoking, second-hand smoke, exposure to certain toxins and family history.
Symptoms include a cough (often with blood), chest pain, wheezing and weight loss. These symptoms often don’t appear until the cancer is advanced.
Treatments vary but may include surgery, chemotherapy, radiation therapy, targeted drug therapy and immunotherapy.
Symptoms of Lung Cancer
- A cough that does not go away or gets worse.
- Coughing up blood or rust-colored sputum (spit or phlegm)
- Chest pain that is often worse with deep breathing, coughing, or laughing.
- Hoarseness.
- Loss of appetite.
- Unexplained weight loss.
- Shortness of breath.
- Feeling tired or weak.
Causes of Lung Cancer
Cigarette smoking is the number one cause of lung cancer. Lung cancer also can be caused by using other types of tobacco (such as pipes or cigars), breathing secondhand smoke, being exposed to substances such as asbestos or radon at home or work, and having a family history of lung cancer.