The thick and sticky mucus associated with cystic fibrosis clogs the tubes that carry air in and out of your lungs:
• A persistent cough that produces thick mucus (sputum)
• Wheezing
• Exercise intolerance
• Repeated lung infections
• Inflamed nasal passages or a stuffy nose
• Recurrent sinusitis
Digestive signs:
• Foul-smelling, greasy stools
• Poor weight gain and growth
• Intestinal blockage, particularly in newborns (meconium ileus)
• Chronic or severe constipation, which may include frequent straining while trying to pass stool, eventually causing part of the rectum to protrude outside the anus (rectal prolapse)
Causes:
In cystic fibrosis, a defect (mutation) in a gene — the cystic fibrosis transmembrane conductance regulator (CFTR) gene — changes a protein that regulates the movement of salt in and out of cells. The result is thick, sticky mucus in the respiratory, digestive and reproductive systems, as well as increased salt in sweat. Many different defects can occur in the gene. The type of gene mutation is associated with the severity of the condition.
Courtesy: Mayo Clinic