Lung cancer is a type of cancer, which affects the lungs. Lungs are an important part of respiratory system and during respiration inhaled air goes to lungs through windpipe or trachea and then distributed through bronchi. Bronchi are small tubes and are widely affected by lung cancer.

Types of Lung Cancer

Lung cancer can be primarily of two types – Small Cell Lung cancer and Non-small cell lung cancer. If the lung is affected by both types of cancer, it is known as mixed cell cancer. Lung cancer, which spreads to other parts of body is called metastatic lung cancer. Other, less common lung cancers are carcinoid tumors, adenoid cystic carcinomas, lymphomas and sarcomas.

Small cell lung cancerĀ 

Small cell lung cancer or SCLC is also known as oat cell carcinoma or small cell undifferentiated carcinoma. It is an aggressive cancer, which grows quickly and is capable of spreading through lymph nodes, bones, brain, adrenal glands, and the liver. Most common risk factor for this disease is tobacco smoking.

Non-small cell lung cancerĀ 

Non-small cell lung cancer or NSCLC may be of various types. It is primarily divided into three categories.

  • Squamous cell carcinoma (SCC): It is caused due to tobacco smoking. It affects the central region of the lungs.
  • Adenocarcinoma: It is the most common type of non-small cell lung cancer. It affects the outer region of the lungs.
  • Large Cell Carcinoma (LCC): It is also a common type of non-small cell lung cancer. It is fast growing cancer and shows poor prognosis after treatment.

Causes and Risk Factors of Lung Cancer

It is one of the most wide spread cancers in the world. It is more common in elderly people or people above 45 years of age. Many few young people get affected by this disease. Smoking is the most common cause of Lung Cancer. Tobacco in cigarettes is held responsible for development of lung cancer in the smoker. More one smokes, more is the increase in risk of lung cancer. Second hand smoke or inhaling the smoke of others may also lead to development of lung cancer. Around 5% of lung cancer patients are non-smokers and have fallen prey to the disease due to second hand smoke. Other risk factors for lung cancer are as follows-

  • Exposure to Asbestos
  • Exposure to uranium, beryllium, vinyl chloride, nickel chromates, coal products, mustard gas, chloromethyl ethers, gasoline, and diesel exhaust, may increase risk of this disease. These chemicals are known as cancer triggers.
  • A person with family history of lung cancer is more likely to develop this disease.
  • High levels of air pollution could lead to inhalation of many harmful gases and substance and hence could increase risk of lung cancer.
  • High levels of arsenic in drinking water may also increase risk of lung cancer.
  • People, who have undergone radiation therapy to the lungs, are at higher risk of developing lung cancer.
  • Radon gas exposure also likely increases risk of this disease.

Symptoms of Lung Cancer

Lung cancer may not show any symptoms in early stages, but with the advancement of disease many symptoms may crop up. If a patient has any of these symptoms, he must consult his doctor and get checked for lung cancer. Symptoms may indicate other diseases as well, but only a doctor can decide if a patient is suffering from lung cancer. Symptoms of lung cancer may differ for each individual patient depending on type and stage of the disease. Symptoms of lung cancer are listed below:-

  • Pain in chest
  • Persistent cough
  • Blood in cough
  • Extreme tiredness or Fatigue
  • Unintended weight loss
  • Loss of appetite or hunger
  • Difficulty in breathing
  • Wheezing
  • Pain or tenderness of bone
  • Drooping eyelids
  • Paralysis of face
  • Alteration in voice
  • Hoarseness of voice
  • Pain in joints
  • Problems in nails
  • Pain in Shoulder
  • Difficulty in swallowing
  • Swelling in the face or arms
  • Weakness

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