Cystic fibrosis is a genetic disease that causes abnormally thick, sticky mucus to develop in the lungs, pancreas and digestive tract.  In the lungs, this mucus clogs airways and causes inflammation, leading to scarring of the lung tissues—frequent infections lead to additional permanent lung damage. In the digestive system, mucus blocks ducts in the pancreas, impairing the release of enzymes required to effectively digest food.
Cystic fibrosis (CF) is the most common fatal genetic (inherited) disease in the United States.  About 30,000 people in the US have CF, and many more carry the gene leading to CF —more than 1 million Americans carry this gene . Two copies of the gene, one from each parent, are required for a child to develop CF. This means if both parents are carriers of the gene that causes CF, a child has a 1 in 4 (25%) chance of having cystic fibrosis, a 50% chance of inheriting the CF carrier gene, and a 25% chance of not inheriting the gene. 
Cystic fibrosis is a serious disease, requiring lifelong treatment. The thick mucus clogging the lungs can make breathing difficult, but also cause lung damage due to frequent infections.  These respiratory infections can be fatal. Eventually, respiratory failure can develop—often, people with cystic fibrosis will require lung transplant , but they must be healthy enough to be able to survive the surgery. 
In recent years, new CF treatments have extended the average lifespan of people with cystic fibrosis. The median age of survival of people with CF is 37 years old for females, and 40 years old for males  In 1980, the median survival was less than 20 years of age . As treatment advances and more options become available, the projected lifespan of people living with cystic fibrosis continues to rise.  Adherence to regular treatment, medical appointments, and addressing co-occurring issues of CF such as osteoporosis and diabetes are imperative to both extending the life of a person with cystic fibrosis, and ensuring the highest possible quality of life.
Information on this page is for reference and educational purposes only. For more information about cystic fibrosis, talk to your doctor or primary care provider.
Page last updated: October 14, 2018
 National Human Genome Research Institute (National Institutes of Health). Learning about cystic fibrosis. Last updated: December 27, 2013 https://www.genome.gov/10001213/learning-about-cystic-fibrosis/
 Cystic Fibrosis Foundation. About cystic fibrosis. https://www.cff.org/What-is-CF/About-Cystic-Fibrosis/
 Cystic Fibrosis Foundation. Carrier testing for cystic fibrosis. https://www.cff.org/What-is-CF/Testing/Carrier-Testing-for-Cystic-Fibrosis/
 National Jewish Health. Lung transplantation: Is it right for you? https://www.nationaljewish.org/conditions/idiopathic-pulmonary-fibrosis-ipf/overview/ipf-management/lung-transplantation-is-it-right-for-you
 Medscape. Median survival in cystic fibrosis soars. https://www.medscape.com/viewarticle/830235#vp_2
 National Jewish Health. Cystic fibrosis life expectancy. Last reviewed: April 1, 2012. https://www.nationaljewish.org/conditions/cystic-fibrosis-cf/life-expectancy