Pulmonary nodule: causes, symptoms and treatment.


If you hear your healthcare provider tell you that you have a lump in your lungs or nodules in your lungs, it can be intimidating. However, these small abnormal lesions are common and generally not a cause for concern. About 95% of lung nodules found on primary CT scan are not cancerous. However, it is important to be diagnosed even if you have never smoked.

This article explains what causes lung nodules, how they are diagnosed, the risk of lung nodules being cancerous, and how to treat them.

Get Medical Information / Emily Roberts


Pulmonary nodules look like "spots" on X-rays and CT scans. They are also sometimes referred to as "coin-shaped lesions" because of their round, coin-like shape.

Pulmonary nodules are three centimeters (cm) or 1.2 inches in diameter or smaller. They must be at least 1 cm in size to be visible on a chest X-ray. CT scans provide more detailed images and can detect nodules that vary in size from 1 to 2 millimeters.

Lesions larger than 3 cm are called lung masses rather than nodules and have an increased risk of malignancy.


Pulmonary nodules are common. They are found in 1 in 500 chest X-rays and 1 in 100 CT scan of the chest. About 150,000 lung nodules are diagnosed in people in the United States each year. About half of adults who have a chest X-ray or CT scan have them.


Nodules in the lungs are so small that they do not cause breathing problems or other symptoms. That is why they are usually found "by accident" or "by accident" when a chest X-ray is taken for some other reason.

If symptoms are present, they may include:

  • Cough
  • Hemoptysis
  • Wheezing
  • Shortness of breath, often mild at first and only with physical activity
  • Respiratory infections if the nodule is near the main airway.


Pulmonary nodules can be benign , which means benign, and malignant , which means cancerous. Most benign nodules in the lungs are the result of inflammation from infection or disease.

When your lungs become inflamed, small masses of tissue can form. Over time, the lumps can develop into a nodule in the lung.

The causes of most benign lung nodules can be divided into several main categories.

  • Infections, including bacterial infections such as tuberculosis and pneumonia; fungal infections from inhalation of spores found in bird or bat droppings, or in damp soil, wood, and leaves; and parasitic infections such as roundworms and tapeworms
  • Inflammation from irritants in the air, air pollution, or autoimmune diseases such as rheumatoid arthritis or sarcoidosis.
  • Scars from surgery or radiation on the chest.

Other less common causes of a pulmonary nodule include:

  • Pulmonary infarction: areas of lung tissue deprived of blood supply)
  • Arteriovenous malformations – a type of abnormality of the blood vessels
  • Atelectasis : collapse of part of the lung.
  • Pulmonary fibrosis : thickening, scarring of the lung tissue.
  • Amyloidosis : accumulation of a type of protein in the lungs.

The most common causes of malignant nodules in the lungs are lung cancer or cancer of other parts of the body that has spread to the lungs.

  • Malignant tumors. Cancers that were first discovered as nodules include lung cancer, lymphomas , sarcomas, carcinoid tumors, and a type of neuroendocrine tumor.
  • Metastases: The nodules can be other cancers, such as breast cancer, colon cancer, bladder cancer, and prostate cancer, that have spread to the lungs. When a nodule is due to metastasis from another cancer, there are often multiple nodules present in the lungs .


There are three diagnoses of pulmonary nodules; benign, malignant or indeterminate. When healthcare professionals see a lung nodule on an X-ray, the first thing they usually do is take any previous X-rays you may have and compare them.

If the nodule has been around for a long time and hasn't changed, it's probably not cancer. Further testing may not be required. However, if you do not have previous X-rays to compare, the nodule has changed, or the nodule is new, further testing may be required.

Your doctor will also receive a detailed medical history from you. The questions will focus on the risk factors you may have for any type of lung nodule.

Examples of some of the questions you may be asked:

  • Do you smoke? Have you ever smoked?
  • Have you had tuberculosis, pneumonia, surgery, or radiation to the chest?
  • What is your job?
  • Have you been exposed to asbestos or radon ?
  • Do you work outdoors?
  • Where did you travel?

For example, if you work outdoors with wood or damp soil, live in the Southwest, or have traveled to certain countries, a fungal or parasite infection may be the cause of a lung nodule. And if you smoke or have smoked before, a malignant tumor may develop.

If the nodule hasn't changed, or your healthcare providers think your risk of cancer is low, they may take a wait-and-see approach. They will force you to take another viewing test in six months or a year. Solitary, solitary nodules that have not changed for two or more years usually do not need further investigation.

Visual tests

If a nodule is found on a chest X-ray, the first step is usually a computed tomography (CT) scan of the chest. CT scans can provide images with a higher level of detail and taken from different angles. This is important because small cancers may not be visible on a chest X-ray .

Healthcare providers may order other tests, including:

  • MRI (Magnetic Resonance Imaging): This imaging test uses magnetic fields and radio frequencies to give your healthcare provider a more detailed view of your node.
  • PET (positron emission tomography): Unlike computed tomography and magnetic resonance imaging, which are "structural" tests, a PET scan is a "functional test." This helps to understand what is happening inside the nodule. These tests are especially helpful for those who have previously had chest radiation, lung infections, or surgeries that can lead to scar tissue.

The number of nodules in the lungs, which radiologists consider "vague," meaning the diagnosis is unclear, has increased with the use of lung cancer screenings. Hearing that your nodule or nodules are vague can be confusing.

Unfortunately, there are times when it is impossible to determine if a node is malignant based solely on imaging tests. To answer this question, a biopsy must be performed. Fortunately, radiologists, surgeons, and pathologists are working together to find less invasive methods of tissue sampling and analysis.


If your nodule changes in size or appearance, your diagnosis is uncertain, or your nodules may be metastatic cancer from another tumor, a sample of your nodule may be needed to determine if it is cancerous.

You can obtain this sample in different ways:

  • Needle biopsy You will be given local anesthesia. Your healthcare provider will use CT scans or even some type of X-ray to guide a needle through your chest and obtain a tissue sample from a nodule in your lung.
  • Bronchoscopy – You will receive a sedative. Your doctor will pass a long, thin fiberoptic tube with a surgical cutting instrument at the end down your throat and into your lung to take a sample of the nodule for laboratory analysis.
  • Watt's biopsy: He was given general anesthesia. Healthcare providers use a special type of video to help insert a tube through the chest wall to obtain a tissue sample from the nodule in the lungs for analysis. They can also remove the entire lung lump.

Research shows that even when a lung nodule is found in a person who can be expected to have lung metastases, only half of the nodules were biopsy metastases. Rather, up to 25% were second primary lung cancers.


To diagnose a pulmonary nodule, your healthcare provider will first ask about your history and risk factors. If a nodule was found on an x-ray, you may need other imaging tests to get more detailed images. In some cases, a sample of the nodule needs to be obtained and examined to confirm the diagnosis.

Cancer risk

Overall, there is a 60% chance that a lung nodule found on an X-ray is benign. The probability that a lung nodule found on CT scan is not malignant is 99%.

However, the actual risk for a person depends on many factors, such as age. In people under 35 years of age, the probability of a malignant lung nodule is less than 1%, while half of all lung nodules in people over 50 are malignant.


Sixty percent of lung nodules found on x-rays are benign, while 99% of lung nodules found on CT scans are not cancerous.

Where you live and where you've traveled can also make a difference. For example, studies have shown that nodules in the lungs caused by schistosomiasis, a parasitic infection, are quite common in African immigrants . Likewise, nodules caused by fungal infections such as coccidioidomycosis are common in the Southwest.

There are other factors that can affect whether the lung nodules found on an X-ray are benign or cancerous.

Low risk of lung cancer.

  • Up to 35 years

  • Small nodule (less than 3 cm in diameter)

  • Patient does not smoke (never smoked)

  • No exposure to toxins in the workplace

  • No history of lung cancer in family members

  • There are no other signs or symptoms of lung cancer.

  • The knots are smooth and round in shape.

  • Nodules are only partially hard

  • The nodules do not grow over time.

  • The nodules are calcified (contain calcium deposits)

  • The inside of the nodule is a "cavity", darker on X-ray images.

  • Only one or more nodules are present

  • Nodules are found in the right or left lower lobe or right middle lobe of the lung.

High risk of lung cancer

  • Over 50 years

  • The nodule is more than 3 cm in diameter.

  • The patient smokes or is a former smoker.

  • Exposure to occupational toxins such as asbestos or radon

  • A first or second degree relative with lung cancer

  • Having symptoms of lung cancer, such as a persistent cough or trouble breathing.

  • The nodules are spike-shaped, the edges are irregular or lobulated.

  • Hard nodules

  • The nodules grow rapidly (on average, they double in size in four months)

  • The nodules show no signs of calcification.

  • Nodules are not cavities

  • The presence of multiple nodules (may indicate lung cancer metastasis)

  • The nodules are found in the upper left or right lobe of the lungs.

Lung cancer screening

Lung cancer screening has been found to reduce lung cancer death rates by 20%.

US health officials recommend that if you are between the ages of 50 and 80, still smoke, have quit in the past 15 years, or have what they call a '20-year smoking history ,' you should get tested. proof. annually for lung cancer.

This measurement allows you to determine how much you have smoked in your life. This means that if you have smoked one pack a day for 20 years or two packs a day for 10 years, you should have a lung cancer screening test annually.

The recommendations call for the use of low-dose computed tomography. The chest x-ray exam does not reduce the risk of dying from lung cancer.

As with any screening test, there is a risk of false positive results and nodules can often be found on CT screening. Finding nodules does not always mean cancer. In fact, research to date shows that only about 5% of the nodules found on the first CT scan of the lungs are malignant.


If you are between the ages of 50 and 80, smoke, have quit in the past 15 years, or have '20 packs of smoking years, 'you should get screened for lung cancer annually. A history of smoking 20 packs of cigarettes means that you have smoked one pack of cigarettes a day for 20 years, or two packs of cigarettes a day for 10 years.

Watch out

Treatment of pulmonary nodules varies greatly depending on the diagnosis. Most benign lung nodules can be left alone, especially those seen on previous imaging tests that have not changed for two or more years.

If your nodule is cancerous, finding such a small size is very curable. In fact, lung cancer treatment and survival rates in general have improved significantly in recent years.


Nodules are "spots" in the lungs that are 3 cm or smaller. Most nodules are not cancerous, but are caused by infection or scarring. They are more likely to develop cancer in people over 50 and in smokers. Some people with an increased risk of lung cancer are advised to get screened for lung cancer.

Get the word of drug information

If you have heard that you or your loved one have a lump in your lungs, you are probably feeling nervous and depressed. There are so many different diagnostic options, and some of them are overwhelming.

While you are being tested and awaiting your diagnosis, it can help to know that most of the nodules in your lungs are not cancerous.

If a nodule in the lung is cancerous, it can be treated very easily. New technologies and treatments have significantly improved the survival rate of people with lung cancer.

Finally, if your nodule turns out to be lung cancer, seek support and help from family and friends. There is also a lung cancer community that will welcome you.

Frequently asked questions

  • Most lung nodules are not cancerous. Sixty percent of those found on X-rays and 99% of those found on CT scan are benign. However, sometimes the nodules in the lungs can be small cancers. That is why it is so important to follow the diagnosis.

  • Some nodules in the lungs can be small and develop cancers. Lung cancer is the leading cause of cancer death in the United States. Up to one fifth of lung cancer deaths in the United States now occur among people who have never smoked or used any form of tobacco.

Related Articles
Choosing foods to diet after a heart attack

All cardiovascular specialists agree that a healthy diet is important to reduce the risk of coronary artery disease (CHD) Read more

Different types of hysterectomies.

A hysterectomy is the surgical removal of all or part of a woman's uterus . Hysterectomy is usually done Read more

Esthetician: experience, specialties and training

An esthetician is a person who specializes in cosmetic skin care. Cosmetologists (sometimes called estheticians ) are not medical Read more

Benefits, Side Effects, Dosages, and Interactions.

CBD oil is an extract from Cannabis indica or Cannabis sativa , the same plants that produce marijuana when Read more