Lung Cancer: Types, Symptoms, Causes, and diagnosis

Lungs cancer types, symptoms and diagnosis

Lungs are two spongy organs inside the chest that bring oxygen to the blood and remove carbon dioxide from our bodies. Lung cancer is the most common type that begins in the lungs and spreads to the lymph nodes and other body parts like the brain, bone, and liver. It is caused by the abnormal growth of lung cells, resulting in a tumor. Furthermore, lung cancer has caused the most deaths throughout the world. 

Types of Lung Cancer

Lung cancers are divided into two groups according to their different growth rate and treatments. They are referred to as small cell and non-small cell cancer. 

  • Small cell lung cancer (SCLC) accounts for about 10 to15% of all this cancer. It is the most fast-growing type of lung cancer and is difficult to cure. Smoking is the common cause of SCLC. Furthermore, SCLC starts in bronchi and spreads fast than NSCLC. The doctor may suggest radiation therapy and chemotherapy treats this  cancer. 
  • Non-small cell lung cancer (NSCLC) is the most common form of cancer of lungs that exists in around 80% to 85% of people with this cancers. Generally, NSCLC starts from different locations and grows slowly compared to SCLC. There are many types of NSCLC, which may include:
  • Adenocarcinoma: Adenocarcinoma is the most common type of tumor that may occur in several body parts. It is formed in the mucus secreted substances in the lungs. The symptoms of adenocarcinomas are weight loss, coughing, bloody mucus, hoarseness, and exhaustion. 
  • Large cell carcinoma: This rapidly growing cancer is also one form of NSCLC. Its symptoms are persistent cough, fatigue, breathing difficulty, chest pain, and wheezing. Chemotherapy is used to treat large cell carcinoma. 
  • Squamous cell carcinoma: It starts in squamous cells. Generally, it appears as a thick, persistent, or rough patch with a scaly, flat surface. The symptoms are headache, fatigue, or weight loss. 

Symptoms of Lung Cancer

The symptoms may depend on the severity of the infection. These are as follows:

  • Chest pain
  • Breathing difficulty
  • Chest infections, like pneumonia and bronchitis
  • Weight loss
  • Persistent cough
  • Coughing with the small amount of blood
  • Headache
  • Wheezing
  • Hoarseness (Changings in someone’s voice tone) 
  • Bone pain
  • Bone fractures
  • Swelling in the chest and lymph nodes
  • Fatigue
  • Pain in swallowing
  • Blood clots

Causes of Lung Cancer

Smoking is a particular cause of cancer of lungs among smokers and secondhand smokers. Around 90% of cancer of lungs is caused by smoking. When a person inhales smoke that contains carcinogenic substances, several changings begin immediately in the lungs. Due to smoking, normal lung cells are excessively damaged, eventually causing cancer cells to develop. The risk of this cancer of lungs reduces by quitting smoking, but the risk of cancer of lungs is higher in smokers than in nonsmokers. 

Risk factors of Lung Cancer

Many factors increase the risk of cancer of lungs, which may include:

  • Smoking: Tobacco smoke consists of 60 carcinogenic substances that damage lung cells. There are many harmful chemicals in cigars, chewing tobacco, snuff, and pipe tobacco. They increase the risk of lung, stomach, mouth, esophagus, pancreas, liver, kidney, and urinary bladder cancer. In addition, cannabis smoke also increases the risk of cancer of lungs. 
  • Passive smoking: If a person doesn’t smoke, continuous exposure to other people smoking increases cancer of lungs risk. Therefore, smoking is not only dangerous for his health but for others. 
  • Radon gas: Radon is a radioactive gas, the second primary reason for lung cancer after smoking. It is formed by breaking uranium into rocks, water, and soil. This gas can travel through pipes or soil, sometimes accumulating in buildings. People in these buildings and homes, when inhaling radon gas, it damages the lungs cells. Furthermore, radon gas causes many deaths. 
  • Other carcinogens: Exposure to other substances and chemicals used in industries and occupations also increases the risk of this cancer. These substances are arsenic, asbestos, diesel, silica, nickel, chromium, and beryllium.   
  • Radiation therapy: Radiation therapy for the chest also increases the risk of cancer of lungs.
  • Family history: People with a family history of cancer of lungs also risk having it. 
  • Diet: When smokers use certain supplements, such as beta carotene, their risk of cancer of lungs increases. 


People should immediately contact the doctor if they feel symptoms like breathing difficulties or persistent cough. The doctor evaluates the symptoms and may recommend different diagnostic tests. These diagnostic tests are as follows: 

  • Imaging tests: These tests reveal the abnormal mass of cancerous cells. CT scan shows small lung lesions; it is done if an X-ray does not show an abnormality.    
  • Sputum cytology: This technique is used to detect the lung secretions of cancerous cells. If a person has a cough that produces sputum, that sputum is checked to identify the lung cancer cells. 
  • Biopsy: Lung biopsy is used to remove the cancer cells. The specialist performs this procedure using many ways, such as bronchoscopy. It is a procedure in which a pulmonologist evaluates the lungs using a flexible tube passed through the mouth into the lungs. Similarly, a needle biopsy takes suspicious samples from lung tissue by using CT images or X-rays. 


Lung cancer treatment depends on its type, treatment of lung cancer may include chemotherapy, surgery, targeted therapy, and radiation therapy. Chemotherapy and radiation therapy can be helpful in treating people with SCLC. 

    • Chemotherapy: In this treatment, particular medications have been inserted in a vein using an intravenous drip or needle to kill the rapidly growing cancer cells in the body. It is effective to treat the different types of NSCLC. Chemotherapy side effects are fatigue, hair loss, sickness, anemia, and sore mouth. 
    • Surgery is a unique technique in which the surgeon removes the cancer tissue. To remove the entire lung is called pneumonectomy; removing the large parts of the lungs is called a lobectomy. 
    • Targeted therapy: In this treatment, drugs are used to stop the growth of cancer cells. These drugs may be in the form of medicines given in the veins or pills to take to cure lung cancer. People may use targeted therapies with or without chemotherapy. Furthermore, they are commonly used for NSCLC treatment rather than SCLC. 
    • Radiation therapy: Radiation oncologists use high-energy rays to kill cancer cells and shrink tumors. People may experience side effects after radiation therapy, such as vomits, hair loss, fatigue, and nausea. 
  • Immunotherapy: This therapy helps the immune system fight lung cancer. Doctors suggest immunotherapy for NSCLC patients. In addition, it has few side effects than radiation or chemotherapy, but some people may face mild side effects such as constipation, headache, diarrhea, fever, chills, and fatigue. 


This cancer may cause potential complications, which are as follows:

  • Breathing problems
  • Hemoptysis (cough with a small amount of blood)
  • Pleural effusion (fluid inside the chest)


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