Lung Nodules

Lung nodule

What are Lung Nodules?

Having an abnormal growth anywhere on your body is worrisome. But when the abnormal growth happens in your lungs, that worry goes up exponentially as our first thought goes to cancer. However, lung nodules are often benign or non-cancerous. In fact, they are usually discovered by accident when an x-ray is taken for an entirely different issue1-4

Lung nodules also known as pulmonary nodules, are a growth of cells in the lungs, they are often described as a spot or spots on the lungs. Approximately 95% of lung nodules are benign while a small percentage of lung nodules are an early indication of lung cancer5. A good indication of whether a lung nodule is benign or not, is seeing if it grows over time; if it remains small and static in growth, there is a high chance that it is not cancerous. However, if the lung nodule is large and continues growing, it might be something more serious.

What are the causes of Lung Nodules?

There are a number of causes of lung nodules, most of them are benign, with only one cause being cancerous. The causes of lung nodules are6,7:

  • Past infections: scarring in the lungs can occur as a result of past infections such as pneumonia.
  • Current infections: infectious diseases such as tuberculosis can cause inflammation in the lungs, these often appear as nodules on x-rays.
  • Air irritants or pollution: able to cause inflammation in the lungs which may cause scarring in the lungs.
  • Autoimmune diseases: for example, sarcoidosis, which causes clumps of inflammatory cells to grow on organs including the lungs.
  • Lung cancer: these are usually characterised by lung nodules that are large and continue to grow and increase in size.

What are the common symptoms?

Lung nodules usually do not cause any symptoms if they are small. However, if the lung nodule begins to grow and becomes large, you may experience the following symptoms:

  • Chest pains
  • Fatigue or lethargy
  • Chronic cough
  • Haemoptysis or coughing up blood
  • Hoarseness
  • Unexplained weight loss
  • Loss of appetite
  • Breathlessness or shortness of breath
  • Recurrent respiratory infections

If you have lung nodules and experience any of the symptoms stated above, make an appointment with a respiratory specialist.

Are Lung Nodules painful?

Most of the time, lung nodules do not cause any symptoms let alone any pain. However, some people may experience chest pains if the lung nodules start to grow.

Who is at risk of Lung Nodules in Singapore?

Any can develop lung nodules; however, you are more likely to develop cancerous lung nodules if you have the following risk factors:

  • Age: individuals older than 65 years old have an increased risk.
  • Family history: having a family history of any type of cancer increases your risk.
  • Smoker: if you smoke or live in a smoke-filled environment increases your risk of lung nodules and other respiratory conditions.
  • Radiation therapy: if you have received radiation therapy to the chest for other types of cancer such as breast cancer, you have an increased risk.
  • Lung conditions: having other lung diseases such as chronic obstructive pulmonary disease (COPD) increases your risk.

How are Lung Nodules diagnosed in Singapore?

Lung nodules are often discovered by accident when an x-ray or computed tomography scan (CT-scan) is taken for something unrelated to it. If the lung nodules are small, you may be required to have a follow-up every 6-12 months after to check if the nodules are growing. Lung nodules that remain static with no growth after 2 years are considered to be benign. However, if the lung nodules are growing, the following tests may be conducted:

  • Bronchoscopy: a long, thin tube with a light and camera attached at one end will be inserted into your throat and gently guided down to your lungs.
  • CT-scan guided biopsy: a sample of the nodule will be taken to be biopsied. This helps to check if the nodule is cancerous.
  • Positron emission tomography (PET) scan: a radioactive glucose solution is injected into the body. Areas of the body with cancer will show a higher and quicker uptake of the glucose solution. 

What are the treatment options for Lung Nodules in Singapore?

Benign and small lung nodules do not require any treatment since they are not causing any symptoms or discomfort. If the lung nodules are causing problems or are cancerous, the following treatment options are available:

  • Thoracotomy: removal of the lung nodule via surgery.
  • Video-assisted thoracoscopy surgery (VATS): another way to remove lung nodules.

Frequently asked questions

What are ground glass lung nodules?

Ground glass nodules usually appear hazy on x-rays and CT-scans. They tend to have a higher likelihood of being cancerous compared to solid lung nodules.

Can lung nodules go away on their own?

If the lung nodules are due to inflammation, they can disappear or shrink when the infection goes away. 


  1. Jeffrey B Alpert, J. P. (2018). Management of Incidental Lung Nodules: Current Strategy and Rationale. Radiologic Clinics of North America, 339-351.
  2. Lea Azour, J. P.-A. (2021). Incidental Lung Nodules on Cross-sectional Imaging: Current Reporting and Management. Radiologic Clinics of North America, 535-549.
  3. Satish Kalanjeri, A. A. (2021). Invasive modalities for the diagnosis of peripheral lung nodules. Expert Review of Respiratory Medicine, 781-790.
  4. Jane P Ko, L. A. (2018). Management of Incidental Lung Nodules. Seminars in Ultrasound, CT, and MR, 249-259.
  5. Annette McWilliams, M. C. (2013). Probability of cancer in pulmonary nodules detected on first screening CT. New England Medical Journal, 910-919.
  6. Stuart, A. (2021, November 1). Benign Lung Tumors and Nodules. Retrieved from WebMD:
  7. Cleveland Clinic Medical Professional. (2021, May 28). Pulmonary Nodules. Retrieved from Cleveland Clinic: 
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