Lung cancer is the leading cancer cause of death among people ages 45 to 70, according to the Merck Manual. Cigarette smoke is cited as the most common contributor to lung cancer. Originating in the lung tissue, lung cancer is considered a primary cancer that carries multiple complications.
Blocked Airway
As lung cancer grows, it can block the major airways of the lungs causing wheezing and, with severe blockage, lung collapse. Blocked airways also cause pneumonia when bacteria become trapped in the alveoli, or the small air sacs of the lungs. Fever and possible sepsis can occur as a result of pneumonia.
Hemoptysis
Hemoptysis, or coughing up blood, can occur in lung cancer. According to the Merck Manual, 20 percent of cases of hemoptysis are caused by lung tumors. If lung cancer grows into a surrounding blood vessel and erodes the vessel, significant blood loss can be experienced. According to American Family Physician, lung cancer can also erode the lining of the airways, which also causes bleeding and hemoptysis.
Nerve Damage
Lung cancer that spreads into the neck and affects the nerves can cause Horner’s syndrome. Horner’s syndrome is characterized by a drooping eyelid, a small pupil and sunken eye as well as decreased sweating on one side of the face. Cancer that is located in the top of the lungs is called a Pancoast tumor and can affect the nerves in the arm, making it weak, painful and numb.
In the mid-chest, cancer can grow into the heart covering called the pericardium and cause irregular heart rhythms and fluid buildup. The esophagus can be constricted by lung cancer causing difficulty swallowing.
Superior Vena Cava Syndrome
Superior vena cava syndrome occurs when lung cancer compresses the superior vena cava, the large vein that returns blood back to the heart from the rest of the body. Swelling of the upper extremities, face, neck and breasts occurs because of the back up of blood. According to Merck Manual, symptoms of superior vena cava syndrome include shortness of breath, headache, distorted vision, dizziness and drowsiness. Bending forward makes the symptoms worse.
Metastasis
Metastasis means that the cancer has spread from its original location to other parts of the body. It does this by entering the bloodstream. Lung cancer typically spreads to the other lung, bones, adrenal glands, brain and liver. Cancer that spreads to the bones can cause significant pain. Spreading to the brain can cause severe headaches, and spreading to the liver and other abdominal organs can cause nausea and vomiting.
