Typically, lung cancer in its early stages does not cause any symptoms, so it can be difficult to catch before it progresses. Many common symptoms of lung cancer are signs of a variety of other diseases as well, so it can be difficult to know for sure whether the cause of these symptoms is in fact lung cancer.
Common symptoms of lung cancer include a persistent cough that may get worse, coughing up blood or rust-covered mucus, chest pain, loss of appetite, weight loss, shortness of breath, wheezing, fatigue or weakness, and chronic infections such as bronchitis or pneumonia.
If lung cancer spreads to other parts of the body, it may cause other symptoms such as bone pain felt in the back or hips, nervous system changes from cancer spreading to the brain (which can include headache, numbness of extremities, dizziness, balance problems, and seizures), jaundice from cancer spreading to the liver, and swelling of lymph nodes such as those in the neck or above the collarbone.
Some lung cancers can cause syndromes, which are groups of specific symptoms. Cancer that affects the upper part of the lungs is sometimes called a Pancoast tumor, and is usually a form of NSCLC. These tumors can affect certain nerves in the eyes and face, causing a group of symptoms known as Horner syndrome. These symptoms include drooping or weakness of one upper eyelid, a smaller pupil in the same eye, little or no sweating on that side of the face, and severe shoulder pain.
Another syndrome, called Superior vena cava (SVC) syndrome, is caused by tumors that back up the blood flow in the veins. This can lead to symptoms such as headaches, dizziness, a bluish-red skin color, swelling in the face, neck, arms, and upper chest. This syndrome has the possibility of becoming life-threatening, so it is important to get it checked right away.