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Cystic fibrosisBy Mayo Clinic staff
Original Article: http://www.mayoclinic.com/health/cystic-fibrosis/DS00287
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Cystic fibrosis is a life-threatening disorder that causes severe damage to the lungs and digestive system.
An inherited condition, cystic fibrosis affects the cells that produce mucus, sweat and digestive juices. These secreted fluids are normally 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 lungs and pancreas.
Cystic fibrosis is most common in white people of Northern European ancestry, but also occurs in Hispanics, African-Americans and some Native Americans. It is rare in people of Asian and Middle Eastern origin.
Although cystic fibrosis requires daily care, most people with the condition are able to attend school and work, and have a better quality of life than in previous decades. Recent improvements in screening and treatments mean most people with cystic fibrosis now live into their 20s and 30s, and some are living into their 40s and 50s.
Cystic fibrosis signs and symptoms vary, depending on the severity of the disease. Even in the same person, symptoms may worsen or improve as time passes. In some children, symptoms begin during infancy. Other people may not experience symptoms until adolescence or adulthood.
Screening of newborns for cystic fibrosis is now performed in all 50 states. As a result, the condition is diagnosed within the first month of life, before symptoms develop. For people born before newborn screening was performed, it's important to be aware of the signs and symptoms of cystic fibrosis.
People with cystic fibrosis tend to have a higher than normal level of salt in their sweat. Parents often can taste the salt when they kiss their children. Most of the other signs and symptoms of cystic fibrosis affect the respiratory system or the digestive system.
Respiratory signs and symptoms
The thick and sticky mucus associated with cystic fibrosis clogs the tubes that carry air in and out of your lungs. This can cause:
- A persistent cough that produces thick spit (sputum) and mucus
- A decreased ability to exercise
- Repeated lung infections
- Inflamed nasal passages or a stuffy nose
Digestive signs and symptoms
The thick mucus can also block tubes that carry digestive enzymes from your pancreas to your small intestine. Without these digestive enzymes, your intestines can't fully absorb the nutrients in the food you eat. The result is often:
- Foul-smelling, greasy stools
- Poor weight gain and growth
- Intestinal blockage, particularly in newborns (meconium ileus)
- Severe constipation
Frequent straining while passing stool can cause part of the rectum — the end of the large intestine — to protrude outside the anus (rectal prolapse). When this occurs in children, it may be a sign of cystic fibrosis. Parents should consult a physician knowledgeable about cystic fibrosis. Rectal prolapse in children may require surgery.
When to see a doctor
Talk to your doctor if your child:
- Isn't growing properly
- Has a persistent cough that produces mucus
- Has repeated lung or sinus infections
- Has frequent fatty, bad-smelling stools
- Has rectal prolapse
Seek immediate medical care if your child has difficulty breathing.
In cystic fibrosis, a defect (mutation) in a gene changes a protein that regulates the movement of salt in and out of cells. The result is thick, sticky mucus in the respiratory, digestive and reproductive systems, as well as increased salt in sweat. Many different defects can occur in the gene. The type of gene mutation is associated with the severity of the condition.
The affected gene, which is inherited from a child's parents, is a recessive gene. Children need to inherit one copy of the gene 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.
- Family history. Because cystic fibrosis is an inherited disorder, it runs in families.
- Race. Although cystic fibrosis occurs in all races, it is most common in white people of Northern European ancestry.
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|Collapsed and normal lung|
The sticky mucus associated with cystic fibrosis causes many complications, the most common in the respiratory, digestive and reproductive systems.
Respiratory system complications
- Bronchiectasis. Cystic fibrosis is one of the leading causes of bronchiectasis, a condition which damages the airways, making it harder to move air in and out of the lungs.
- Chronic infections. Thick mucus in the lungs and sinuses provides an ideal breeding ground for bacteria and fungi. People with cystic fibrosis may have frequent bouts of sinusitis, bronchitis or pneumonia.
- Nasal polyps. Because the lining inside the nose is inflamed and swollen, it can develop soft, fleshy growths (polyps). Nasal polyps can obstruct your breathing during sleep.
- Cough up blood. Over time, cystic fibrosis can cause thinning of the airway walls. As a result, teenagers and adults with cystic fibrosis may cough up blood (hemoptysis).
- Pneumothorax. This condition, in which air collects in the space that separates the lungs from the chest wall, is also more common in older people with cystic fibrosis. Pneumothorax can cause chest pain and breathlessness.
- Collapsed lung. Repeated lung infections damage the lungs, making it more likely for the lung to collapse.
- Respiratory failure. Over time, cystic fibrosis can damage lung tissue so badly that it no longer works. Lung function typically worsens gradually, and it eventually can become life-threatening.
Digestive system complications
- Nutritional deficiencies. Thick mucus can block the tubes that carry digestive enzymes from your pancreas to your intestines. Without these enzymes, your body can't absorb protein, fats or fat-soluble vitamins.
- Diabetes. The pancreas produces insulin, which your body needs to use sugar. Cystic fibrosis increases the risk of diabetes. Nearly 20 percent of people with cystic fibrosis develop diabetes by age 30.
- 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 and sometimes gallstones.
- Rectal prolapse. Frequent coughing or straining during constipation can cause internal rectal tissue to protrude outside the anus.
- Intussusception. Children with cystic fibrosis are at higher risk of intussusception, a condition in which a section of the intestines folds in on itself like an accordion. The result is bowel obstruction, an emergency that requires immediate treatment.
Reproductive system complications
Almost all 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, so be sure to discuss the possible risks with your doctor.
- Osteoporosis. People with cystic fibrosis are at higher risk of developing osteoporosis, a dangerous thinning of bones.
- Electrolyte imbalances. Because people with cystic fibrosis have saltier sweat, the balance of minerals in their blood may be upset. Signs and symptoms include increased heart rate, fatigue, weakness and low blood pressure.
Preparing for your appointment
Newborns in all 50 states are routinely screened for cystic fibrosis. For adults or older children who weren't screened at birth, make an appointment with your doctor if you or your child has signs or symptoms common to cystic fibrosis. After the initial evaluation, you may be referred to a doctor who specializes in cystic fibrosis.
Here's some information to help you prepare for your appointment, as well as what to expect from your doctor.
What you can do
You may want to write a list that answers these questions:
- What symptoms are you or your child experiencing?
- When did the symptoms start, and does anything make them better or worse?
- Has anyone in your family ever had cystic fibrosis?
- Has growth been normal and weight been stable?
What to expect from your doctor
After obtaining detailed information about the symptoms and your family's medical history, your doctor may order some tests to help with diagnosis.
Tests and diagnosis
Newborn screening and diagnosis
Every state in the U.S. now routinely screens newborns for cystic fibrosis. Early diagnosis means treatment can begin immediately. In the screening test, a blood sample is checked for higher than normal levels of a chemical (immunoreactive trypsinogen, or IRT) released by the pancreas.
A newborn's IRT may be high because of premature birth or a stressful delivery. For that reason other tests are needed to confirm a diagnosis of cystic fibrosis:
- Sweat test. A sweat-producing chemical is applied to a small area of skin. The collected sweat is then tested to see if it's saltier than normal.
- Genetic testing. DNA samples from blood or saliva can be checked for specific defects on the gene responsible for cystic fibrosis.
The sweat test is usually done when the infant is a month old, to ensure the sample is large enough to be analyzed. The sweat test can determine if the infant carries the cystic fibrosis gene or has the condition. Testing should be done at a center specializing in cystic fibrosis.
Testing of older children and adults
Cystic fibrosis tests may be recommended for older children and adults who weren't screened at birth. Your doctor may suggest genetic and sweat tests for cystic fibrosis if you have recurring bouts of inflamed pancreas (pancreatitis), nasal polyps, chronic sinus or lung infections, bronchiectasis, or male infertility.
Testing after diagnosis
If you have cystic fibrosis, you will need regular tests to help manage the condition:
- Imaging tests. Damage to your lungs or intestines can be monitored with X-rays, CT scans and MRI.
- Lung function tests. These tests measure the size of your lungs, how much air you can breathe in and out, how fast you can breathe in and out, and how well your lungs deliver oxygen to your blood.
- Sputum culture. Your spit (sputum) is analyzed for bacteria.
- Organ function tests. Blood tests can measure the health of your pancreas and liver. Children with cystic fibrosis should be regularly tested for diabetes after age 10.
Treatments and drugs
There is no cure for cystic fibrosis, but treatment can ease symptoms and reduce complications. Close monitoring and early, aggressive intervention is recommended. Managing cystic fibrosis is complex, so consider obtaining treatment at a center that specializes in cystic fibrosis.
The goals of treatment include:
- Preventing and controlling lung infections
- Loosening and removing mucus from the lungs
- Preventing and treating intestinal blockage
- Providing adequate nutrition
The options include:
- Antibiotics to treat and prevent lung infections
- Mucus-thinning drugs to help you cough up the mucus, which improves lung function
- Bronchodilators to help keep your airways open by relaxing the muscles around your bronchial tubes
- Oral pancreatic enzymes to help your digestive tract absorb nutrients
Chest physical therapy
Loosening the thick mucus in the lungs makes it easier to cough up. Chest physical therapy helps loosen mucus and is usually done from one to four times a day. A common technique is clapping with cupped hands on the front and back of the chest.
Mechanical devices also can help loosen lung mucus. The options include:
- Chest clapper, a hand-held device that mimics the effect of cupped hands clapping over the ribs
- Inflatable vest, a device worn around the chest that vibrates at high frequency
- Breathing devices, usually a tube or mask through which you exhale while performing breathing exercises
Your doctor may recommend a long-term program to improve your lung function and overall well-being. Pulmonary rehabilitation is usually done on an outpatient basis and may include:
- Exercise training
- Nutritional counseling
- Energy-conserving techniques
- Breathing strategies
- Psychological counseling or group support or both
Surgical and other procedures
- Nasal polyp removal. Your doctor may recommend surgery to remove nasal polyps that obstruct breathing.
- Oxygen therapy. If your blood-oxygen level declines, your doctor may recommend you sometimes breathe pure oxygen to prevent high blood pressure in the lungs (pulmonary hypertension).
- Endoscopy and lavage. Mucus may be suctioned from obstructed airways through an endoscope.
- Lung transplant. If you have severe breathing problems, life-threatening lung complications or increasing resistance to antibiotics used to treat lung infections, lung transplantation may be an option. Because both lungs are affected by cystic fibrosis, both need to be replaced. Lung transplants for people with cystic fibrosis are controversial because studies indicate the procedure is associated with many complications, and may not prolong life or enhance quality of life.
- 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 into the abdomen.
- Bowel surgery. If a blockage develops in your bowel, you may need surgery to remove it. Intussusception, where a section of bowel has folded in on itself, also may require surgical repair.
Lifestyle and home remedies
There are many things you can do at home to minimize cystic fibrosis complications. Always talk to your doctor before starting home remedies.
Cystic fibrosis can cause malnourishment because the enzymes needed for digestion can't reach your small intestine, preventing food from being absorbed. People with cystic fibrosis need 50 percent more calories daily than people without the condition. The best possible nutrition also is necessary to maintain good lung function. In addition to enzyme replacements prescribed by your doctor, consider adding:
- Supplemental high-calorie nutrition
- Special fat-soluble vitamins
- Extra fiber to prevent intestinal blockage
- Extra salt, especially during hot weather
Drink lots of fluids
Increasing fluid intake can help thin the mucus in your lungs.
Keep immunizations up to date
In addition to other usual childhood vaccines, people with cystic fibrosis should have the annual influenza vaccine. Cystic fibrosis doesn't affect the immune system, but children with cystic fibrosis are more likely to develop complications when they become sick.
Regular exercise helps loosen mucus in your airways, and strengthens your heart and lungs. For many people with cystic fibrosis, participating in sports can improve confidence and self-esteem. Anything that gets you moving, including walking and biking, can help.
Don't smoke in your home or car, and don't allow other people to smoke around your child. Secondhand smoke is harmful for everyone, but especially for people with cystic fibrosis.
Teach all the members of your family to wash their hands thoroughly before eating, after using the bathroom, when coming home from work or school, and after being around a person who is sick. Hand-washing is the best way to protect against infection.
Coping and support
If you or someone you love has cystic fibrosis, you may experience strong emotions such as anger or fear. These issues are especially common in teens. Talking openly about how you feel can help. It may also help to talk with others who are dealing with the same issues.
That might mean joining a support group for parents of children with cystic fibrosis. Older children with the disorder may want to join a cystic fibrosis group to meet and talk with others who have the disease. Psychologists are often an important part of the care team as the child approaches the teen years.
If you or your partner has close relatives with cystic fibrosis, you both might want to undergo genetic testing before having children. The test, which is performed in a lab on a sample of blood or saliva, can help determine your risk of having a child with cystic fibrosis.
If you're already pregnant and the genetic test shows that your baby may be at risk of cystic fibrosis, your doctor can conduct additional tests on your developing child.
Genetic testing isn't for everyone. Before you decide to be tested, you should talk to a genetic counselor about the psychological impact the test results might carry.
- What is cystic fibrosis? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/cf/. Accessed March 26, 2012.
- Goldman L, et al. Cecil Medicine. 24th ed. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-1-4377-1604-7..C2009-0-42832-0--TOP&isbn=978-1-4377-1604-7&uniqId=327451096-2. Accessed March 26, 2012.
- Kliegman RM, et al. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa.: Saunders Elsevier; 2011. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-1-4377-0755-7..C2009-0-60010-6--TOP&isbn=978-1-4377-0755-7&uniqId=327451096-2. Accessed March 27, 2012.
- Cystic fibrosis. National Library of Medicine. http://ghr.nlm.nih.gov/condition/cystic-fibrosis. Accessed April 2, 2012.
- What is bronchiectasis? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/dci/Diseases/brn/brn_whatis.html. Accessed March 27, 2012.
- Cohen-Cymberknoh M, et al. Managing cystic fibrosis: strategies that increase life expectancy and improve quality of life. American Journal of Respiratory and Critical Care Medicine. 2011;183:1463.
- Rogan MP, et al. Cystic fibrosis transmembrane conductance regulator intracellular processing, trafficking, and opportunities for mutation-specific treatment. Chest. 2011;139:1480.
- Mogayzel PJ, et al. Update in cystic fibrosis 2010. American Journal of Respiratory and Critical Care Medicine. 2011;183:1620.