Diagnosis

To diagnose your condition, your doctor may review your medical and family history, discuss your signs and symptoms, review any exposure you've had to dusts, gases and chemicals, and conduct a physical exam. During the physical exam, your doctor will use a stethoscope to listen carefully to your lungs while you breathe. He or she may also suggest one or more of the following tests.

Imaging tests

• Chest X-ray. A chest X-ray shows images of your chest. This may show the scar tissue typical of pulmonary fibrosis, and it may be useful for monitoring the course of the illness and treatment. However, sometimes the chest X-ray may be normal, and further tests may be required to explain your shortness of breath.
• Computerized tomography (CT) scan. CT scanners use a computer to combine X-ray images taken from many different angles to produce cross-sectional images of internal structures in the body. A high-resolution CT scan can be particularly helpful in determining the extent of lung damage caused by pulmonary fibrosis. Also, some kinds of fibrosis have characteristic patterns.
• Echocardiogram. An echocardiogram uses sound waves to visualize the heart. It can produce still images of your heart's structures, as well as videos that show how your heart is functioning. This test can evaluate the amount of pressure occurring in the right side of your heart.

Lung function tests

• Pulmonary function testing. Several types of pulmonary function tests may be conducted. In a test called spirometry, you exhale quickly and forcefully through a tube connected to a machine. The machine measures how much air your lungs can hold and how quickly you can move air in and out of your lungs. Other tests may be conducted to measure your lung volumes and diffusing capacity.
• Pulse oximetry. This simple test uses a small device placed on one of your fingers to measure the oxygen saturation in your blood. Oximetry can serve as a way to monitor the course of the disease.
• Exercise stress test. An exercise test on a treadmill or stationary bike may be used to monitor your lung function when you're active.
• Arterial blood gas test. In this test, your doctor tests a sample of your blood, usually taken from an artery in your wrist. The oxygen and carbon dioxide levels in the sample are then measured.

Tissue sample (biopsy)

If other tests haven't diagnosed the condition, doctors may need to remove a small amount of lung tissue (biopsy). The biopsy is then examined in a laboratory to diagnose pulmonary fibrosis or rule out other conditions. The tissue sample may be obtained in one of these ways:

• Bronchoscopy. In this procedure, your doctor removes very small tissue samples — generally no larger than the head of a pin — using a small, flexible tube (bronchoscope) that's passed through your mouth or nose into your lungs. The tissue samples are sometimes too small for an accurate diagnosis. The biopsy may also be used to rule out other conditions.

  The risks of bronchoscopy are generally minor and might include a temporary sore throat or discomfort in your nose from the passage of the bronchoscope. However, serious complications can include bleeding or a deflated lung.

  During bronchoscopy, your doctor may conduct an additional procedure called bronchoalveolar lavage. In this procedure, your doctor injects salt water through a bronchoscope into a section of your lung, and then immediately suctions it out. The solution that's withdrawn contains cells from your air sacs.

  Although bronchoalveolar lavage samples a larger area of the lung than other procedures do, it may not provide enough information to diagnose pulmonary fibrosis. It might also be used to rule out other conditions.

• Surgical biopsy. Although a surgical biopsy is more invasive and has potential complications, it may be the only way to obtain a large enough tissue sample to make an accurate diagnosis. This procedure may be done as a minimally invasive surgery, called video-assisted thoracoscopic surgery (VATS), or as an open surgery (thoracotomy).

  During VATS, your surgeon inserts surgical instruments and a small camera through two or three small incisions between your ribs. The camera allows your surgeon to view your lungs on a video monitor while removing tissue samples from your lungs. This procedure is performed after you've been given a general anesthetic, so you'll be asleep during the procedure.

  During open surgery (thoracotomy), a surgeon removes a lung sample through an incision in the chest between your ribs. The procedure takes place after you've been given a general anesthetic.

Blood tests

Doctors may also order blood tests to evaluate your liver and kidney function, and to test for and rule out other conditions.