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Cystic fibrosis

Cystic fibrosis (CF) is a disease caused by a defect in a gene that helps produce mucus. Mucus is the fluid that coats the lining of airways and other passageways in your body. Mucus prevents these passageways from drying out or becoming infected. Normally, mucus is watery. But CF causes the mucus to be thick and sticky. This type of mucus clogs the lungs, making it hard to breathe. It also makes it easy for germs to infect the lungs. Over time, these infections can damage the lungs.

The thick, sticky mucus can also make it hard for the small intestine to break down food. As a result, many of the nutrients in food are not absorbed, so a person with CF can become malnourished. People with CF are also at increased risk for diabetes and osteoporosis. CF also causes infertility in men, and it can make it harder for women to get pregnant.

The symptoms and severity of CF vary from person to person and also can vary over time. The most common symptoms of CF include:

  • Frequent coughing that brings up thick mucus
  • Frequent lung infections (such as bronchitis and pneumonia)
  • Salty-tasting skin (because the sweat glands produce sweat that is high in salt)
  • Diarrhea or bulky, foul-smelling, and greasy stools
  • Huge appetite but poor weight gain
  • Stomach pain and discomfort caused by too much gas in the intestines

As the disease gets worse, the symptoms become more severe. CF has no cure. But early and ongoing treatment for CF can improve quality of life and lifespan. Treatment usually involves nutritional and respiratory therapies, medicines, and exercise. A healthy lifestyle also is an important part of managing CF.

Although CF requires daily care, most people with CF are able to attend school or work and live a normal life in many ways. Still, living with a chronic disease like CF and its symptoms can be stressful and hard to cope with, especially as the disease gets worse. Let your doctor and loved ones know how you are feeling and what they can do to help you.

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Content last updated: September 22, 2009.

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