People with CF lose excessive amounts of salt when they sweat. This can upset the balance of minerals in the blood, which may cause abnormal heart rhythms. Going into shock is also a risk. Mucus in CF patients is very thick and accumulates in the intestines and lungs. The result is malnutrition, poor growth, frequent respiratory infections, breathing difficulties, and eventually permanent lung damage.
Lung disease is the usual cause of death in most patients.
CF can cause various other medical problems. CF symptoms vary from child to child. A baby born with the CF genes usually has symptoms during its first year. Sometimes, however, signs of the disease may not show up until adolescence or even later. CF should be suspected in babies born with an intestinal blockage called meconium ileus.