What Is Cystic Fibrosis?

Cystic fibrosis is an inherited chronic disease that affects the lungs and digestive system of about 30,000 children and adults in the United States (70,000 worldwide). A defective gene and its protein product cause the body to produce unusually thick, sticky mucus that:

  • clogs the lungs and leads to life-threatening lung infections; and
  • obstructs the pancreas and stops natural enzymes from helping the body break down and absorb food.

In the 1950s, few children with cystic fibrosis lived to attend elementary school. Today, advances in research and medical treatments have further enhanced and extended life for children and adults with CF. Many people with the disease can now expect to live into their 30s, 40s and beyond.

Symptoms of Cystic Fibrosis

People with CF can have a variety of symptoms, including:

  • very salty-tasting skin;
  • persistent coughing, at times with phlegm;
  • frequent lung infections;
  • wheezing or shortness of breath;
  • poor growth/weight gain in spite of a good appetite; and
  • frequent greasy, bulky stools or difficulty in bowel movements

Diagnosis – Most people are diagnosed with CF at birth through newborn screening, or before the age of 2. A doctor who sees the symptoms of CF will order a sweat test or a genetic test to confirm the diagnosis.

A sweat test is the most common test used to diagnose cystic fibrosis and is considered the diagnostic “gold standard.” A small electrode is placed on the skin (usually on the arm) to stimulate the sweat glands. Sweat is then collected and the amount of chloride, a component of salt in the sweat, is measured. A high level of chloride means that the person has cystic fibrosis.

For children who are less than six months old:

  • Chloride levels at or above 60 mmol/L (a measure of concentration) means the child has CF.
  • Chloride levels between 30 and 59 mmol/L are considered borderline and need to be examined on a case-by-case basis.
  • Chloride levels below 30 mmol/L are considered negative for CF.

For people over the age of six months:

  • Chloride levels at or above 60 mmol/L means the person has CF.
  • Chloride levels between 40 and 59 mmol/L are boderline.
  • Chloride levels below 40 mmol/L are considered negative for CF.

Organizations

 Cystic Fibrosis Foundation