The severity of cystic fibrosis symptoms is different from person to person. The most common symptoms are:
- Very salty-tasting skin
- Persistent coughing that usually produces phlegm
- Frequent lung infections
- Wheezing or shortness of breath
- Poor growth/weight gain in spite of a good appetite
- Frequent greasy, bulky stools or difficulty in bowel movements
- Small, fleshy growths in the nose called nasal polyps
New research shows that the severity of CF symptoms is partly based on the types of CF gene mutations, or defects. Scientists have found more than 1,500 different mutations of the CF gene.
How and why does CF affect the body?
Scientists have many different ideas about what goes wrong in the lungs of a person with cystic fibrosis, but it all begins with defective CF genes.
Normally, the healthy CF gene makes a protein — known as CFTR (Cystic Fibrosis conductance Transmembrane Regulator) — that is found in the cells that line various organs, like the lungs and the pancreas. This protein controls the movement of electrically charged particles, like chloride and sodium (components of salt) in and out of these cells.
When the protein is defective, as in cystic fibrosis, the salt balance in the body is disturbed. Because there is too little salt and water on the outside of the cells, the thin layer of mucus that helps keep the lungs free of germs becomes very thick and difficult to move. And because it is so hard to cough out, this mucus will clog the airways and lead to infections that damage lungs.
In addition, the mucus that builds up in people with CF can block tubes, or ducts, in the digestive system. The pancreatic duct is especially vulnerable; when it is blocked, enzymes that help digest food cannot reach the intestines, and the body cannot properly absorb nutrition from food. The resulting malnutrition compromises the body’s immune system and can lead to diarrhea, poor growth and weight loss.
The reproductive system is also affected by CF, which can cause infertility, particularly in men. At least 97 percent of men with CF are infertile but are not sterile; they can have children with assisted reproductive techniques. Some women also have fertility difficulties due to thickened cervical mucus or malnutrition.
Sources: Cystic Fibrosis Foundation; Cystic Fibrosis Research Inc.