Fibrosis is the formation of excess fibrous tissues or scar tissue, usually because of injury or long-term inflammation. The two most well-known types of this condition are pulmonary fibrosis, which affects the lungs; and cystic fibrosis (CF), which affects the mucus glands. There also are many other types, including those that affect the heart, skin, joints and bone marrow. Cirrhosis of the liver also is a type of this condition.
There are many potential causes of this condition. It is sometimes caused by disease or the treatment of a disease. Other causes include injuries, burns, radiation, chemotherapy and gene mutation. Some types of this condition are idiopathic, which means that the causes are unknown.
Fibrosis causes the affected tissues to harden. They sometimes also swell. These changes can make the tissues unable to function properly. For example, the flow of fluids through the affected tissues is often reduced. When the condition is present in the lungs, they are unable to expand as normal, causing a shortness of breath.
In the lungs, this condition is called pulmonary fibrosis, and it involves the overgrowth, hardening and/or scarring of lung tissue because of excess collagen. In addition to shortness of breath, the common symptoms include a chronic dry cough, fatigue, weakness and chest discomfort. A loss of appetite and rapid weight loss also are possible. This condition usually affects people between the ages of 40 and 70, and men and women are equally affected. The prognosis for patients with this disease is poor, and they usually are expected to live an average of only four to six years after diagnosis.
Another common form of this condition is CF, a chronic, progressive and often fatal genetic disease of the body's mucus glands. Symptoms sometimes include abnormal heart rhythms, malnutrition, poor growth, frequent respiratory infections and breathing difficulties. This condition can also cause other medical problems, including sinusitis, nasal polyps and hemoptysis, or the coughing of blood. Abdominal pain and discomfort, gassiness, and rectal prolapse also are possible.
CF primarily affects the respiratory and digestive systems in children and young adults. The symptoms are often apparent at birth or shortly thereafter; rarely do the signs not show up until adolescence. It is most commonly found in Caucasians, and the prognosis is moderate, with many patients living for as long as 30 years after diagnosis. Although this form of fibrosis was once characterized by death in childhood, modern doctors view it as a chronic illness, with the majority of patients living to adulthood. There was no cure as of 2012, however, and most patients eventually succumb to lung failure or other infections of the respiratory tract.