Alveoli
Very small air sacs found in the lungs. Click here to see how the alveolar tissue changes with IPF.

Antifibrotic/antifibrogenic agents
Experimental medications used to suppress the scarring process associated with IPF.

Antioxidants
Experimental medications that may prevent or reverse lung tissue damage caused by IPF.

Azathioprine
A medication commonly prescribed for IPF patients that can suppress the activity of the immune system and reduce inflammation.

Bronchoalveolar lavage (BAL)
A diagnostic technique in which fluid is instilled into the lungs and removed for examination.

Clubbing
A buildup of tissue in the fingertips (or sometimes the toes). Clubbing is a sign of advanced IPF. Click here to see what clubbing looks like.

Collagen
Proteins found in tendons, bones, and connective tissue. Scar tissue found in the lungs of patients with IPF also contains collagen.

Computed tomography (CT or CAT scan) or high-resolution computed tomography (HRCT)
A type of x-ray for which a computer is used to construct a three-dimensional image from a series of cross-sectional images. The procedure generates multiple pictures of your lungs in layers (slices) from the top (at your shoulders) to the bottom (just above your waist). This test requires that you lie on a table while the pictures are taken, holding your breath and letting it out as instructed.

Corticosteroids
Medications used to suppress the activity of the immune system and reduce inflammation. The most commonly prescribed corticosteroid is prednisone.

Cyclophosphamide
A medication commonly prescribed for IPF patients that can suppress the activity of the immune system and reduce inflammation.

Cytokines
Molecules produced by the immune system. A cytokine imbalance may be the cause of IPF.

Dyspnea
Shortness of breath or labored breathing usually associated with physical exertion.

Epidemiology
The incidence, distribution, and control of a disease in a population.

Etiology
The cause(s) of a disease.

Familial
Tending to occur in more members of a family than would be expected by chance alone.

Fibrosis
An abnormal scarring of body tissue.

Histopathology
Tissue changes (e.g., scarring of the lungs) that accompany a disease and are recognized by microscopic examination.

Hypertension
High blood pressure.

Hypoxemia
A lack of oxygen in the blood.

Hypoxia
A lack of oxygen in the tissues of the body.

Idiopathic
Arising spontaneously or from an obscure or unknown cause.

Idiopathic pulmonary fibrosis (IPF)
A disease characterized by progressive scarring (fibrosis) and deterioration of the lungs.

Interferon gamma-1b
A regulatory cytokine that has antifibrotic and antifibrogenic effects and may regulate macrophage, fibroblast, and mast cell function; inhibit a variety of neutrophil-derived cytokines; and modify the balance of Th1 and Th2 cells in the lung.

Interstitial lung disease (ILD)
A general term for the approximately 200 disorders characterized by inflammation and scarring (fibrosis) of the lungs' interstitium. IPF is an example of an interstitial lung disease.

Interstitium
The tissue layers between the lungs' air sacs (alveoli) and blood vessels.

Lung biopsy
A procedure in which a tissue sample is obtained through a flexible tube or by means of a small surgical incision between the ribs.

Lung transplant
Replacement of a lung or lungs with donor organ(s).

Monoclonal antibodies
Experimental medications for the treatment of IPF. They may inhibit "bad" cytokines.

Pathogenesis
The mode of origin or development of a disease.

Pathology
The abnormalities that characterize a particular disease.

Phase I trial
The first phase of drug testing in humans. It usually involves 20 to 100 subjects and focuses on safety.

Phase II trial
The second phase of drug testing in humans. It involves up to several hundred patients, lasts as long as two years, and focuses on safety and effectiveness.

Phase III trial
The third phase of drug testing in humans. It involves several hundred to several thousand patients, often lasts several years, and focuses on safety, dosage, and effectiveness.

Prednisone
The most commonly prescribed therapy for IPF. Prednisone is a corticosteroid that can suppress the activity of the immune system and reduce inflammation.

Prognosis
The prospect for survival and recovery from a disease.

Pulmonary
Having to do with the lungs.

Pulmonary embolism
A blood clot in the lungs.

Pulmonary fibrosis
Thickening and scarring of the lungs, specifically the pulmonary interstitium.

Pulmonary hypertension
High blood pressure in the lungs.

Usual interstitial pneumonia (UIP)
A condition indicated by specific changes in the lung tissue. Finding UIP in a lung biopsy strongly points to a diagnosis of IPF (although other criteria must be met).