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Cystic Fibrosis (CF)

What is Cystic Fibrosis?

Cystic fibrosis is an inherited disease of your mucus and sweat glands. It affects mostly your lungs, pancreas, liver, intestines, sinuses, and sex organs. Normally, mucus is watery. It keeps the linings of certain organs moist and prevents them from drying out or getting infected. But in CF, an abnormal gene causes mucus to become thick and sticky. The mucus builds up in your lungs and blocks the airways. This makes it easy for bacteria to grow and leads to repeated serious lung infections. Over time, these infections can cause serious damage to your lungs.

The thick, sticky mucus can also block tubes, or ducts, in your pancreas. As a result, digestive enzymes that are produced by your pancreas cannot reach your small intestine. These enzymes help break down the food that you eat. Without them, your intestines cannot absorb fats and proteins fully.


Most of the symptoms of cystic fibrosis are caused by the thick, sticky mucus. The most common symptoms include:

  • Frequent coughing that brings up thick sputum, or phlegm (flem).
  • Frequent bouts of bronchitis and pneumonia. They can lead to inflammation and permanent lung damage.
  • Salty-tasting skin.
  • Dehydration.
  • Infertility (mostly in men).
  • Ongoing diarrhea or bulky, foul-smelling, and greasy stools.
  • Huge appetite but poor weight gain and growth. This is called "failure to thrive." It is a result of chronic malnutrition because you do not get enough nutrients from your food.
  • Stomach pain and discomfort caused by too much gas in your intestines.



First, your doctor will obtain a detailed medical and family history and perform a thorough physical examination. Next, your doctor may order some tests to ensure an accurate diagnosis, including:

  • A sweat test to measure the amount of salt in your sweat. High salt levels mean CF.
  • Blood tests to look for an abnormal CF gene or other things that indicate CF.
  • A chest x ray takes a picture of your lungs. It can show scarring from inflammation in your lungs.
  • Sinus X-ray for signs of sinusitis.
  • Lung function tests.
  • Sputum (phlegm) cultures.


There still is no cure for CF, but treatments have improved greatly in recent years. The goals of CF treatment are to prevent and control infections in your lungs, loosen and remove the thick mucus from your lungs, prevent blockages in your intestines, and provide adequate nutrition.

The main treatments for lung problems include:

  • Antibiotics for infections of the airways
  • Chest physical therapy
  • Exercise
  • Other medications like anti-inflammatory medications to help reduce the inflammation in your lungs caused by ongoing infections.

Management of Digestive Problems

Nutritional therapy can improve your growth and development, strength, and exercise tolerance. It may also make you strong enough to resist some lung infections. Nutritional therapy includes a well-balanced, high-calorie diet that is low in fat and high in protein. As part of your nutritional therapy, your doctor may recommend:

  • Oral pancreatic enzymes to help you digest fats and proteins and absorb more vitamins.
  • Supplements of vitamins A, D, E, and K to replace the fat-soluble vitamins that your intestines cannot absorb.
  • A feeding tube to add more calories at night while you are sleeping.
  • Enemas and mucus-thinning medications to treat intestinal blockages
  • Medicines that reduce stomach acid and help the oral pancreatic enzymes work better

Cystic Fibrosis is managed by physicians, nurses and other clinical staff in the Division of Pulmonary Medicine at Hopkins Children’s.