Diagnosis

Blood tests help search for causes of ILD. Basic blood tests include:

• Complete blood count (CBC) to check the types of cells in your blood
• Complete metabolic panel to check how well your liver and kidneys work
• Tests to see how well your blood clots

Other blood tests check for collagen vascular or autoimmune diseases or infections such as:

• Dermatomyositis or polymyositis (see The Myositis Foundation)
• Infections like tuberculosis and hepatitis
• Lupus
• Rheumatoid arthritis (see Arthritis Foundation)
• Sarcoidosis
• Scleroderma (see Scleroderma Foundation)
• Sjögren’s syndrome (see Sjögren’s Foundation)
• Vasculitis (see Vasculitis Foundation)

Lung function tests show how your lungs work and how they handle exercise, sleep and other activities.

Pulmonary Function Test (PFT): The PFT is a series of breathing exercises. It takes about 45 minutes and is done multiple times a year to check for any progression of ILD. The PFT checks:

• How much air your lungs can hold
• How quickly and forcefully you can breathe in and out
• How well oxygen can move in and out of your lungs

Types of PFT tests include:

• Spirometry: A simple test performed in your doctor’s office that measures how much air you inhale and exhale
• Pulse oximetry: An electronic device that measures the amount of oxygen in your red blood cells

Six-Minute Walk Test: This test checks how far you can walk in 6 minutes. During a 6-minute walk test, you wear a heart rate and oxygen saturation monitor while you walk. The test is repeated during the year to see if your lung function changes. It also determines if you need to use oxygen.

Overnight Oximetry: This test records your oxygen levels while you sleep, which helps your doctor decide if you need oxygen therapy while you sleep. This test is different from an evaluation for sleep apnea, which requires an overnight sleep study.

Imaging allows doctors to see your chest, lungs and other organs so they can make an accurate diagnosis.

X-Ray: A chest X-ray gives your doctor a quick view of your chest, lungs, and heart.

Computed Tomography (CT) Scan: A CT scan uses a computer to combine many

X-rays taken from different angles. It gives a very precise view of your organs. A high-resolution CT (HRCT) scan allows your doctor to see your lungs with more detail than traditional CT.

Echocardiography: An echocardiogram is an ultrasound of your heart. It uses sound waves to create pictures of your heart. This test helps your doctor know if ILD is affecting your heart. It will also tell your doctor if you have a type of high blood pressure that affects the blood vessels of your lungs (pulmonary hypertension).

Sometimes your doctor might need to take a small amount of tissue from your lungs to make a correct diagnosis. This is called lung biopsy. Watch this video to learn more about lung biopsies.

Bronchoscopy: During a bronchoscopy, a long, bendable tube with a camera is placed in your nose or mouth and inserted into your windpipe (trachea). The camera allows your doctor to see inside your lungs. Tools can then be used to collect fluid.

You will need anesthesia for this test:

• Local anesthesia numbs the pain in an area of your body but does not make you tired.
• General anesthesia puts you to sleep.

Cryobiopsy: Some providers perform this newer tissue sample test. A bronchoscopy is performed, and a small region of your lung is frozen with a special tool. You will need anesthesia and may need to stay in the hospital for observation. Cryobiopsies are usually performed at large academic hospitals.

Video-Assisted Thoracoscopic Surgery (VATS): This tissue sample test is a type of lung surgery. A surgeon will use a few small incisions in your chest in between your ribs to insert tools into the chest cavity. Your doctor will use a camera to help guide the procedure and take a larger tissue sample from your lung. You will need general anesthesia to be put to sleep for the test. This test usually requires an overnight hospital stay. Find out more about VATS (PDF).

Thoracotomy: During a thoracotomy, a surgeon opens your chest with an  incision and takes a few samples of your lung tissue. You will have a tube in your chest (chest tube) for several days after the surgery as you recover in the hospital.

CT Guided Needle Biopsy: Your doctor may be able to take a sample of lung tissue with a needle while also performing a CT scan. However, this is not the best way to get a tissue sample and diagnose a person with ILD. During a needle biopsy (PDF), the skin where the needle is inserted is numbed with local anesthesia, so you won’t need to be asleep.