Two people with cystic fibrosis dating each other
This thick, sticky mucus clogs passages in many of the body's organs and infection sets in.
The two organs most affected are the lungs and pancreas, where the thick mucus causes breathing and digestive problems.
However, these tests also won't always detect a CF gene.
Doctors diagnose most kids with CF by the time they are 3 years old, but if someone has a milder form of the disease, it may not be diagnosed until that person reaches the teen years.
The ends of the toes and fingers may become rounded and enlarged, a condition that's called clubbing.
If doctors suspect that a person has CF, they will order a sweat test.
They may also take antibiotics to prevent or fight lung infections.
They may have trouble growing or gaining weight because of digestive problems.
Adults with CF may also develop other illnesses, such as diabetes (when blood sugar is too high) or osteoporosis (a weakening of the bones).
The thicker mucus has trouble moving out of the lungs, so bacteria can remain and cause infections.
The thick mucus also is in the pancreas — an organ that produces proteins called enzymes that flow into the intestine to support the body's digestion process.