A test, used in the diagnosis of cycstic fibrosis, that measures the level of sodium and chloride excretions from the sweat glands.

The sweat test is used in the diagnosis of cystic fibrosis (CF), an incurable, inherited disease that affects the sweat glands, as well as glands in the lungs, intestines, bile duct, and pancreas. The test is administered as soon as CF is suspected, either because of a family history or symptoms such as frequent colds, recurrent lung infections, recurrent diarrhea, difficulty absorbing food, and slower-than-normal growth. Because early diagnosis and treatment can often ease the severity of the disease, sweat tests may be administered as early as the first week of life. However, this is recommended only when a family history of CF exists or symptoms specific to the disease are exhibited. Sweat tests should never be given for minor breathing problems. Because siblings...