Overview

A malignant tumor called lung cancer starts in the cells of the lungs, usually in the lining of the air passages. It happens when abnormal cells grow out of control and can spread to other tissues or organs far away. There are two main types of lung cancer: non-small cell lung cancer and small cell lung cancer. This is based on how the cells look under a microscope. It's hard to find early because there aren't many symptoms at first. Screening people at high risk can lead to better outcomes.

Symptoms
Some common signs include a persistent cough, coughing up blood, chest pain, shortness of breath, and unexplained weight loss. You might experience hoarseness, fatigue, and recurrent respiratory infections. In the later stages, symptoms may include bone pain, headaches, or swelling of the face and neck as the cancer spreads. Symptoms that come on early are often mild or mistaken for other illnesses.

Causes
Smoking, even second-hand smoke, is the biggest risk factor for lung cancer. Exposure to radon gas, asbestos, air pollution, and some chemicals used at work are other things that can put you at risk. A family history of cancer and previous radiation therapy to the chest may also raise the risk. Although less frequently, non-smokers can still get lung cancer.

Diagnosis
Imaging tests such as chest X-rays and CT scans are used to detect abnormal growths as part of the diagnostic process. PET scans may check for spread. To confirm the diagnosis and find out what kind of cancer it is, a biopsy is needed. More tests help determine the stage of the disease and plan the best treatment.

Treatment
The type and stage of cancer will determine how it is treated. The majority of treatment includes surgery, chemotherapy, radiation therapy, targeted therapy, and immunotherapy. Surgery alone may be enough to treat cancers that are still in their early stages. Combination therapy is often needed for more severe cases.

The stage of lung cancer at diagnosis and the person's overall health affect the outlook. Finding it early makes a big difference in how long people live. Not smoking and taking part in screening programs for people at high risk can help lower the death rate.