Cystic fibrosis is a life-threatening disorder that causes severe lung damage and nutritional deficiencies.
An inherited condition, cystic fibrosis affects the cells that produce mucus, sweat and digestive juices. Normally, these secretions are thin and slippery, but in cystic fibrosis, a defective gene causes the secretions to become thick and sticky. Instead of acting as a lubricant, the secretions plug up tubes, ducts and passageways, especially in the pancreas and lungs.
Cystic fibrosis happens most often in white people of northern European ancestry, occurring in about 1 out of 3,000 live births. In the past, most people with cystic fibrosis died in their teens. Improved screening and treatments now allow many people with cystic fibrosis to live into their 30s or even longer.
One of the first signs of cystic fibrosis is an excessively salty taste to the skin. People with cystic fibrosis tend to have higher than normal amounts of salt in their sweat. Parents often can taste the salt when they kiss their child.
In cystic fibrosis, a defective gene alters a protein that regulates the normal movement of salt (sodium chloride) in and out of cells. This results in thick, sticky secretions in the respiratory and digestive tracts, as well as in the reproductive system. It also causes increased salt in sweat.
The affected gene, which is inherited from a child's parents, is a recessive gene. With recessive genes, children need to inherit two copies of the gene, one from each parent, in order to have the disease. If children inherit only one copy, they won't develop cystic fibrosis, but will be carriers and possibly pass the gene to their own children.
Most of the other signs and symptoms of cystic fibrosis affect the respiratory system or the digestive system.
Respiratory signs and symptoms
■Persistent cough
■Wheezing
■Repeated lung infections
■Repeated sinus infections
Digestive signs and symptoms
■Poor weight gain and growth
■Distended abdomen
■Intestinal blockage, particularly in newborns
Many different types of complications can occur with cystic fibrosis. The most common complications affect the respiratory, digestive and reproductive systems.
Respiratory system complications
■ Bronchiectasis. Cystic fibrosis is one of the leading causes of bronchiectasis, a condition in which damaged airways widen and become flabby and scarred.
■Chronic infections. Thick mucus in the lungs and sinuses provide an excellent breeding ground for bacteria. Most people with cystic fibrosis have almost constant infections in their lungs and sinuses.
■Collapsed lung. Repeated lung infections damage the lungs, making it more likely for the lung to collapse.
■Nasal polyps. Because the lining inside the nose is inflamed and swollen, it's more likely to develop large or multiple polyps — soft, fleshy growths inside your nose.
■Respiratory failure. Over time, cystic fibrosis can damage lung tissue so badly that it won't work anymore. Lung function typically worsens gradually, and it eventually can become life-threatening.
Digestive system complications
■Nutritional deficiencies. Thick mucus blocks the tubes that carry digestive enzymes from your pancreas to your intestines. Without these enzymes, your body can't absorb protein, fats or the fat-soluble vitamins — A, D, E and K.
■Diabetes. The pancreas also produces insulin, which your body needs to use sugar. Cystic fibrosis increases your risk of developing diabetes.
■Blocked bile duct. The tube that carries bile from your liver and gallbladder to your small intestine may become blocked and inflamed, leading to liver problems, such as cirrhosis, and sometimes gallstones.
Reproductive system complications
Many men with cystic fibrosis are infertile because the tube that connects the testes and prostate gland (vas deferens) is either blocked with mucus or missing entirely. Certain fertility treatments and surgical procedures sometimes make it possible for men with cystic fibrosis to become fathers.
Although women with cystic fibrosis may be less fertile than other women, it's possible for them to conceive and to have successful pregnancies. Still, pregnancy can worsen the signs and symptoms of cystic fibrosis.
Other complications
■Osteoporosis. People with cystic fibrosis are at higher risk of developing osteoporosis, a dangerous thinning of bones. This may be linked to the body's inability to absorb vitamin D, which helps build strong bones.
■Electrolyte imbalances. Because people with cystic fibrosis have saltier sweat, this can upset the balance of minerals in their blood. Symptoms include increased heart rate, fatigue, weakness and low blood pressure.
There is no cure for cystic fibrosis, but treatments can ease symptoms and reduce complications.
Medications
■Antibiotics. These drugs are used to treat and prevent lung infections. They may be swallowed in pill form, inhaled in a mist or delivered intravenously.
■Mucus-thinning drugs. Drugs that reduce the stickiness of your mucus make it easier to cough up the mucus, which improves lung function.
■Bronchodilators. Medications such as albuterol — delivered by an inhaler or a nebulizer — help keep your airways open by relaxing the muscles around your bronchial tubes.
Therapy
People with cystic fibrosis need a way to physically remove thick mucus from their lungs. This is often done by manually clapping with cupped hands on the front and back of the chest — a procedure that's best performed with the person's head over the edge of the bed so that gravity helps clear the secretions.
There also are mechanical devices that help loosen lung mucus. They include:
■Chest clapper. This hand-held device can mimic the effect of cupped hands clapping over the ribs.
■Inflatable vest. This device vibrates at high frequency to loosen chest mucus.
■Breathing devices. Performing specific breathing exercises while exhaling through the device's tube or a mask may also be helpful.
Surgical and other procedures
■Feeding tube. Cystic fibrosis interferes with digestion, so you can't absorb nutrients from food very well. Your doctor may suggest using a feeding tube to deliver extra nutrition while you sleep. This tube may be threaded through your nose to your stomach, or surgically implanted.
■Lung transplant. Your doctor may suggest lung transplantation if you have severe breathing problems, life-threatening pulmonary complications or increasing resistance to antibiotics used to treat lung infections. Because both lungs are affected by cystic fibrosis, both need to be replaced. Lung transplantation is a major operation and may lead to serious complications, especially post-surgical infections.
Information taken from:
http://www.mayoclinic.com/health/cystic-fibrosis/DS00287
© 1998-2010 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.
