Cystic fibrosis is an inherited disease. It causes cells to produce mucus that is sticky and thicker than normal. This mucus builds up, particularly in the lungs and organs of the digestive tract.
Cystic fibrosis affects many parts of the body, including the lungs, liver, pancreas, urinary tract, reproductive organs and sweat glands. Certain cells in these organs normally make mucus and other watery secretions. But in cystic fibrosis, these cells produce secretions that are thicker than normal. This leads to other problems.
In the lungs, thick secretions trap germs. This leads to repeated lung infections.
In the pancreas, thick secretions block the normal flow of pancreatic juices. This makes it more difficult for the body to digest and absorb fats and fat-soluble vitamins. This can lead to nutritional problems, especially in babies.
Other problems related to cystic fibrosis include:
Liver problems, including cirrhosis
Infertility, especially in males.
To develop cystic fibrosis, a person must inherit two cystic fibrosis genes. One gene is inherited from each parent.
People who inherit only one cystic fibrosis gene are called cystic fibrosis carriers. They can pass the cystic fibrosis gene to their children. But they do not have the disease themselves.