What is cystic fibrosis (CF)?

Cystic fibrosis (CF) is a genetic disease that causes sticky, thick mucus to build up in organs including the lungs and the pancreas. In a healthy person, mucus that lines organs and body cavities, such as the lungs and the nose, is slippery and watery. In people with CF, thick mucus clogs the airways, making breathing troublesome. Its blockage of the ducts in the pancreas causes problems with digesting food. Babies and children with CF may not be able to absorb enough nutrients from food. Other organs that CF affects are the liver, sinuses, intestines, and sex organs. CF is a condition that is chronic (long-lasting) and progressive (getting worse over time).

What are the symptoms of cystic fibrosis?

Children with CF have the following symptoms:

  • Failure to thrive (inability to gain weight despite having good appetite and taking in enough calories)
  • Loose stools or oily stools
  • Trouble breathing
  • Recurrent wheezing
  • Frequent lung infections (recurrent pneumonia or bronchitis)
  • Recurrent sinus infections
  • A nagging cough
  • Slow growth

What causes cystic fibrosis?

CF is a disease that is passed through genes called the CFTR genes. People with CF inherit two faulty genes, one from each parent. The parents do not have to have CF. Many families do not have a family history of CF. In this case, the person with the faulty gene is called the carrier. About one in 31 people in the United States are carriers who are free of CF symptoms.

How common is cystic fibrosis?

Among white children in the United States, the rate of CF cases is one in 3,500 newborns. CF affects about one in 17,000 black newborns and one in 31,000 newborns of Asian descent.

How is cystic fibrosis diagnosed?

In most cases, CF is diagnosed during childhood. Doctors diagnose CF by a thorough evaluation and using different tests. These include:

  • Newborn screening—A health care provider takes a few drops of blood from a heel prick, usually while the newborn is in the hospital. The provider places the drops of blood on a special card known as a Guthrie card. Tests at a laboratory can diagnose conditions including CF. All states in the U.S. require the testing of newborns at birth as well as a few weeks later.
  • Sweat test—This is the most conclusive testing for CF. Sweat tests measure the amount of chloride in the body’s sweat, which is elevated in people with CF. People of any age can have a sweat test. In the test, a health care provider applies a chemical called pilocaprine to the skin. He or she then applies a small amount of electric stimulation to encourage the sweat glands to produce sweat. The provider then collects the sweat in a plastic coil or on a piece of filter paper or gauze. The test is not painful and does not use a needle.
  • Genetic tests— These are performed using a blood sample that is tested for the faulty genes that cause CF.
  • Chest X-rays—X-rays of the chest are used to support or confirm CF if a health care provider suspects that a person has the disease. Other forms of testing need to be used to confirm the presence of CF.
  • Sinus X-rays—As with chest X-rays, sinus X-rays can confirm CF in patients showing certain symptoms of CF. Other forms of testing are used along with sinus X-rays.
  • Lung function tests—The most common lung function test uses a device called a spirometer. The patient breathes in completely. He or she then empties the inhaled breath into the mouthpiece of the spirometer.
  • A sputum culture—A health care provider takes a sample of a patient's sputum (spit) and tests it for bacteria. Certain bacteria, such as pseudomonas, are most commonly found in people with CF.

How is cystic fibrosis treated?

In most cases, the patient visits a CF care center four times a year. The center shows the patient techniques for the clearing of mucus from the airways, which will aid in keeping their lungs healthier. They also detect complications of CF and treat these in a timely manner. The centers also offer medications and information about nutrition therapy and physical fitness.

What are the complications related to cystic fibrosis?

Adults with CF can have problems with breathing, digestion, and the reproductive organs. The thick mucus present in people with CF can hold bacteria, causing infection to occur more often. People with CF have a higher risk of developing diabetes or the bone-thinning conditions of osteopenia and osteoporosis. Men with CF are not able to father children without the aid of alternative reproductive technology. Women with CF can have complications in pregnancy.

What is the outlook for patients with cystic fibrosis?

There is not a cure for CF and it cannot be prevented. However, new treatment methods help children with CF to live well into adulthood and have a better quality of life. Advances in the treatment of CF have increased the expected age of survival from the mid-teens in the 1970s to more than 36 years old currently. Therapies are most helpful when CF is diagnosed early, which is why newborn screening is so important. These young patients can thus begin receiving the earliest, most up-to-date and aggressive therapy. These therapies include treating infections, helping to prevent weight loss, and being seen frequently by a CF specialist .


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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 12/16/2015...#9358

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