Lung cancer is the abnormal growth of tissues in the lungs. When a person breathes, air goes down the trachea (windpipe) and into the lungs, where it spreads through tubes called bronchi (air passages). Most lung cancers begin in the cells that line these tubes. Types of lung cancer There are 2 main types of lung cancer: Non-small cell lung cancer is the most common type of lung cancer Small cell lung cancer is less common, but spreads quickly to other parts of the body through the blood

Lung Cancer - Symptoms & Causes

Symptoms & Causes Diagnosis & Treatment Our Expertise & Doctors FAQ

What is lung cancer?

Lung cancer is the abnormal growth of tissues in the lungs.

When a person breathes, air goes down the trachea (windpipe) and into the lungs, where it spreads through tubes called bronchi (air passages). Most lung cancers begin in the cells that line these tubes.

Lung cancer

Types of lung cancer

There are 2 main types of lung cancer:

Non-small cell lung cancer is the most common type of lung cancer
Small cell lung cancer is less common, but spreads quickly to other parts of the body through the blood

What are the symptoms of lung cancer?

Early stage lung cancer often does not cause symptoms. As the cancer grows, the following symptoms may appear:

A cough that gets worse or does not go away
Breathing difficulties, such as being short of breath
Constant chest pain
Coughing up blood
A hoarse voice
Feeling very tired all the time
Frequent lung infections, such as pneumonia
Unexplained weight loss

As these symptoms may also be related to other health problems, it is best to consult a doctor if you experience these symptoms to confirm your diagnosis.

What causes lung cancer?

The main cause of lung cancer is tobacco smoke from cigarettes, pipes or cigars.

Harmful substances in tobacco smoke damage the lung cells. Inhaling second-hand smoke from people smoking nearby can also cause lung cancer.

What are the risk factors of lung cancer?

You may be at risk for lung cancer if you:

Are older than 40 years – Most people are older than 65 years when they are diagnosed with lung cancer
Have contact with certain substances such as radon (a radioactive gas), asbestos, arsenic, chromium, nickel and air pollution
Have family members with a history of lung cancer