Babies are born with (Cystic Fibrosis) CF when they inherit faulty genes from both their parents.
CF is a disease in which the secretions from various glands are thick and sticky instead of being watery and free flowing.  The lungs and digestive system are particularly affected. A build up of thick mucus in the lungs reduces the ability to clear bacteria leading to cycles of infection and inflammation which damage the delicate lung tissues.

Lung function is progressively lost and respiratory failure is the major cause of death in CF patients.
The lower intestine can also become blocked by a build up of mucus, but the major digestive problem concerns the pancreas.

The pancreas, a gland situated behind the stomach, secretes digestive enzymes into the intestine.
In most CF patients the pancreas is damaged and fails to produce the enzymes required for proper digestion of food.  This means that food is not digested properly and can cause serious malnutrition. 

The pancreas has another important function the production of insulin.  
This is usually unaffected by CF in early life but diabetes is becoming an increasingly common complication in older patients. Liver damage can be another late-onset complication of CF.

Cystic Fibrosis also affects the reproductive system and most men with CF are infertile. However, women usually experience only slightly reduced fertility, if at all.  Other complications of CF can be sinusitis, nasal polyps and arthritis. 

CF is a variable disease, the organs involved being affected to differing degrees.
Survival varies correspondingly, however, the average survival time is currently around 30 years.
This represents a three-fold increase during the past thirty years and is attributable to improved treatments
and the development of specialist CF treatment centers.