Lung cancer

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Symptoms of lung cancer

Lung cancer may not cause any signs or symptoms in its early stages. Signs and symptoms often appear as the tumour grows and causes changes in the body, such as a cough or shortness of breath. Other health conditions can cause the same symptoms as lung cancer.

Many of the signs or symptoms for non–small cell lung cancer and small cell lung cancer are the same. See your doctor if you have these signs or symptoms of both types of lung cancer:

  • a cough that gets worse or doesn’t go away
  • shortness of breath
  • chest pain that you can always feel, and that gets worse with deep breathing or coughing
  • blood in mucus coughed up from the lungs
  • wheezing
  • weight loss
  • fatigue
  • hoarseness or other changes to your voice
  • difficulty swallowing
  • swollen lymph nodes in the neck or above the collarbone
  • headache
  • bone pain

Non–small cell lung cancer

Non–small cell lung cancer can cause Horner syndrome. This is a group of symptoms caused by lung cancer growing into the nerves found at the top of the lung. See your doctor if you have this group of symptoms:

  • eye changes – drooping of the eyelid or a smaller pupil in the eye
  • very little or no sweating on the side of the face as the eye changes

Small cell lung cancer

A paraneoplastic syndrome is a group of symptoms that occurs when substances released by cancer cells affect the normal function of other organs or tissues. Small cell lung cancer is more likely than non–small lung cancer to cause paraneoplastic syndromes.

See your doctor if you have any of these groups of symptoms.


Syndrome of inappropriate antidiuretic hormone (SIADH) is when the body makes too much antidiuretic hormone (ADH). Symptoms of SIADH include muscle weakness and cramping, restlessness, confusion, fatigue, nausea and vomiting. Find out more about SIADH.

Cushing syndrome is when the body makes high amounts of corticosteroids. Symptoms of Cushing syndrome include high blood pressure, high blood sugar, a round face with thin arms and legs, and muscle weakness. It may also cause weight gain that causes purple marks on the stomach.

Lambert-Eaton syndrome is caused by the lack of a chemical that transmits messages between muscles and nerves. Symptoms of Lambert-Eaton syndrome include muscle weakness, loss of movement, and difficulty chewing, climbing stairs or lifting objects.

Paraneoplastic cerebellar degeneration is a very rare paraneoplastic syndrome. It is caused when the body’s immune system has an abnormal reaction and attacks the cells of the central nervous system. Symptoms of this disorder include dizziness, nausea, a loss of balance, blurred vision, rapid eye movements, shaking (tremors) and problems with speaking or swallowing.

When to see your doctor right away about a symptom

In some cases, lung cancer or its treatment can cause serious problems.

Superior vena cava syndrome occurs when the cancer obstructs the large vein (superior vena cava) that returns blood from the head and arms, resulting in headache and swelling of the head and neck. It is a serious cancer-related emergency that needs to be treated right away.

Spinal cord compression occurs when cancer spreads to the spine and compresses the spinal cord, resulting in back pain, weakness in the legs or change in bladder or bowel function. It is a serious cancer-related emergency that needs to be treated right away.

See your healthcare team as soon as possible if you have any symptoms of superior vena cava syndrome or spinal cord compression.