If your doctor runs tests to look at your lungs, they may see something unexpected. Unusual substances in your lungs are known as lung infiltrates, or pulmonary infiltrates. Lung infiltrates can show up during screening tests and may be a sign of lung cancer or another underlying health problem (a condition you already have).

If you’ve been diagnosed with lung cancer or have symptoms of lung disease, you may be concerned about lung infiltrates. In this article, we’ll cover important information you should know about lung infiltrates and how they may be related to cancer. If you have any questions, reach out to your doctor — they can give you more information about the types of diagnostic tests they use and what comes next if lung infiltrates are found.

What Are Lung Infiltrates?

Lung infiltrates include biological materials that are not normally found in the lung, though they can be found in other parts of the body. These might be different substances, such as:

• Pus
• Immune cells
• Tumor cells
• Blood
• Proteins
• Water or fluid

Some types of lung infiltrates may also be considered lung consolidation (or pulmonary consolidation). This term refers to substances in the open spaces inside the lungs where there should be air. Your doctor may also mention lung consolidation when talking about lung infiltrates, but not all types of lung infiltrates are lung consolidation.

What Causes Lung Infiltrates?

Lung infiltrates can be caused by health conditions that damage the lung tissue. Malignancies (cancers) that affect the lungs — including lung cancer or other cancers that spread to the lungs — can lead to lung infiltrates. Other conditions that have been linked to lung infiltrates include:

• Bacterial, viral, or fungal infections
• Reactions to certain drugs
• Pulmonary hemorrhage (bleeding in the lungs)
• Pulmonary edema (buildup of fluid in the lungs)
• Pulmonary embolism (blood clot in the lungs)
• Interstitial lung diseases, conditions that cause scarring of the lungs
• Autoimmune diseases, such as sarcoidosis and lupus
• Pneumonitis caused by an allergic reaction or exposure to radiation
• Lung injury

Lung infiltrates can occur more often in people with weakened immune systems. This is because they have less protection from infections and are more likely to have complications like pneumonia.

In some cases, lung infiltrates are related to more serious conditions. These include acute respiratory distress syndrome, a severe lung problem that stops enough oxygen from reaching the blood, and pulmonary embolism, a blockage in one of the lung’s blood vessels. These conditions require immediate medical attention and can be life-threatening if not treated quickly.

What Are the Symptoms of Lung Infiltrates?

Diseases that can lead to lung infiltrates can negatively affect lung function. If your lungs aren’t working as well as they should, you may have symptoms like:

• Dyspnea (shortness of breath)
• Chest pain
• Feverishness and tiredness
• Rough or rapid breathing
• Hemoptysis (coughing up blood or blood-stained mucus)

Although these symptoms can certainly point to a problem with your lungs, different diseases may cause some of the same symptoms. Therefore, if you haven’t already been diagnosed with lung cancer or another condition, your doctor likely won’t be able to make a diagnosis based on symptoms alone.

How Are Lung Infiltrates Diagnosed?

If you’re having breathing problems or other symptoms, your health care provider will start by looking at your medical history to understand if you have any risk factors for lung cancer or other diseases. They may also use different approaches to see if there are problems with your lungs.

Radiology

Studying the lungs usually involves radiology techniques, which are imaging tests that allow a doctor to see the tissues inside the body. A chest X-ray or CT scan may be used to diagnose different diseases that affect the lungs.

Your doctor may not be specifically looking for lung infiltrates, but if any are present, they may be able to see them on the chest X-ray or CT scan. Lung infiltrates or other lesions (abnormal marks) can cause the image to have a different appearance compared to a scan of a healthy lung.

Bronchoscopy

Doctors aren’t always able to make a diagnosis based on radiology results alone. If this happens, they may use another technique called a bronchoscopy. The doctor uses a long tube with a light on the end to get a closer look at the inside of your lungs.

During a bronchoscopy, your doctor may also collect fluid from inside your lungs — this procedure is known as bronchoalveolar lavage (BAL). Once collected, the fluid can be studied more closely in a laboratory. The BAL fluid may contain a fungus or bacteria that can help your doctor better understand the cause of the lung infiltrates.

Biopsy

If the cause of lung infiltrates remains unclear even after a bronchoscopy, your doctor may need to collect a sample of lung tissue, also known as a lung biopsy. A CT scan or a bronchoscopy may be used to help collect the sample.

A doctor can then look at the tissue sample under a microscope and perform additional laboratory tests. Lung biopsies can help doctors confirm whether someone has lung cancer or another health issue.

Are Lung Infiltrates Harmful?

Although the main concern is generally the underlying health condition that’s affecting the lungs, lung infiltrates themselves may make it hard for the lungs to work properly. If your lungs aren’t able to get enough oxygen into the blood, this can cause respiratory failure and prevent you from breathing properly. One study cited in the journal Critical Care showed that lung infiltrates were associated with a higher risk of respiratory failure in people with cancer.

How Are Lung Infiltrates Treated?

Lung infiltrates are typically not treated directly. Rather, the underlying condition that’s causing lung infiltrates should be treated. The best treatment option varies, depending on the health condition you have.

Infections are one of the most common causes of lung infiltrates. Treatment with antibiotics or antiviral medication can help clear up the infections, and the lung infiltrates should go away.

For people with lung cancer, cancer treatments like radiation therapy or chemotherapy are commonly used to destroy cancer cells. Although these treatments can help lower the levels of lung infiltrates, they may not disappear completely because cancer is a long-term health condition that requires ongoing management.

How Are Lung Infiltrates Connected to Lung Cancer?

Lung infiltrates don’t necessarily mean you’re at a higher risk for getting lung cancer, but they may be a sign that you have lung cancer. If you’ve been diagnosed with another type of cancer, finding lung infiltrates could be a sign that the cancer has spread to the lungs.

If you’ve been diagnosed with lung cancer and tests show lung infiltrates, this may change your treatment plan. Adjusting the treatment can help prevent serious breathing issues and boost your chances of getting better. Your doctor will use the test results to create the best treatment plan for you.

Talk With Others Who Understand

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