Central line
An intravenous (IV) line that is placed into a large (central) vein in the body.

CF-related diabetes (CFRD)
A type of diabetes found in CF patients that results from decreased function of the pancreas due to scarring, which decreases the amount of insulin produced. It is usually diagnosed by measuring the patient’s blood glucose (sugar), which is elevated in those with diabetes. This type of diabetes is slightly different from Type I (juvenile-onset) and Type II (adult-onset) diabetes, and usually begins during early adulthood. Symptoms may include weight loss and muscle wasting, fatigue, decreased ability to respond to infections, respiratory problems, increased thirst and urination, and delayed puberty. Treatment may include insulin injections, nutrition management, and daily measurement of blood glucose levels. About 15 percent of CF patients develop CF-related diabetes.

CFTR (Cystic fibrosis transmembrane conductance regulator)
CFTR is located on chromosome 7 and encodes a chloride channel that sits on the surface of specialized cells throughout the body. Mutations in the CFTR gene led to cystic fibrosis.

Clubbing
Enlargement and rounding of the nailbeds of the fingers and toes, usually found in symptomatic CF patients older than 4 years of age. Clubbing is usually due to chronic respiratory problems, although it can be caused by several other medical conditions. The medical name for clubbing is hypertrophic osteoarthropathy.

Congenital bilateral absence of the vas deferens (CBAVD)
An absence of the tube (vas deferens) that transports sperm out of the testis leading to infertility in most men with cystic fibrosis.

Diabetes
See CF-related diabetes.

Distal intestinal obstruction syndrome (DIOS)
A blockage of the intestines due to the accumulation of stool in the small or large intestine. DIOS is often a sign of intestinal malabsorption. Patients develop progressive symptoms of recurrent, crampy abdominal pain, bloating, nausea, loss of appetite and decreased stooling. About 10-20 percent of patients with CF develop this syndrome. The incidence of DIOS tends to increase with age. DIOS is treated with laxatives and enemas. Preventive measures can include staying well hydrated, taking adequate pancreatic enzyme supplementation, increasing dietary fiber, and taking prescribed stool softeners or laxatives.

Enzyme
Substance needed for the proper digestion and absorption of food nutrients. Enzymes are produced mainly by the pancreas.

Epithelial cell
A specialized type of cell that lines the airways, intestines and other organs. A lining of epithelial cells is called and epithelium.

Expectorate
The process of removing mucus or sputum from the throat or lungs by coughing and spitting.

FEV1 (Forced expiratory volume in one second)
A measure of lung function that shows that amount of air a patient can forcefully exhale from the lungs in one second. This measure is compared to a predicted normal value that is based on the patient’s age and height.

Flu
See Influenza

FVC (Forced vital capacity)
The maximum amount of air the can be exhaled from the lungs after a maximum inspiration. This measure is compared to a predicted normal value that is based on the patient’s age and height.