Overview
What is cystic fibrosis? A Mayo Clinic expert explains
Learn more from pulmonologist Sarah ChalmersM.D.
Hello. I'm Dr. Sarah Chalmersa pulmonologist at Mayo Clinic. In this videowe'll cover the basics of cystic fibrosis. What is it? Who gets it? The symptomsdiagnosis and treatment. Whether you're looking for answers for yourself or someone you lovewe're here to give you the best information available. Cystic fibrosis is a disorder that damages your lungsdigestive tract and other organs. It's an inherited disease caused by a defective gene that can be passed from generation to generation. Cystic fibrosis affects the cells that produce mucussweat and digestive juices. These secreted fluids are normally thin and slippery. But in people with CFthey're thick and sticky. Instead of acting as lubricantsthese secretions plug up the tubesducts and airways in your body. Although there is no cure for cystic fibrosispeople with this condition are generally able to live normal lives. There are many tools and techniques doctors use to help manage this complicated condition and with improvement in screening and treatmentslife expectancy for those with cystic fibrosis is better than ever before.
Simply putcystic fibrosis is a gene defect. A defect to this gene changes how a salt moves in and out of cellsresulting in thicksticky mucus in the respiratorydigestive and reproductive systems. It's an inherited condition. A child needs to inherit one copy of the mutated gene from each parent to develop cystic fibrosis. If they only inherit one copy from one parentthey won't develop it. Howeverthey will be a carrier of that mutated geneso they could pass it along to their own children in the future. Because CF is an inherited disorderfamily history determines your risk. Although it can occur in all racescystic fibrosis is most common in white people of North European ancestry.
There are two kinds of symptoms associated with cystic fibrosis. The first are respiratory symptoms. Thicksticky mucus can clog the tubes that carry air in and out of your lungs. This can trigger a persistent cough that produces thick mucuswheezingexercise intolerancerepeated lung infectionsand inflamed nasal passages or a stuffy nose or recurrent sinusitis. The second type of symptoms are digestive. That same thick mucus that can clog your airways can also bog tubes that carry enzymes from your pancreas to your small intestine. This can result in foul-smelling or greasy stoolspoor weight gain and growthintestinal blockageor chronic and severe constipationwhich may include frequent straining while trying to pass stool. If you or your child show symptoms of cystic fibrosis or if someone in your family has CFtalk with your doctor about testing for the disease.
Since this disease is an inherited conditionreviewing your family history is important. Genetic testing may be done to see if you carry the mutated gene that triggers cystic fibrosis. A sweat test may also be conducted. CF causes higher than normal levels of salt in your sweat. Doctors will examine the levels of salt in your sweat to confirm a diagnosis.
Because this condition is passed from parent to childrennewborn screening is routinely done in every state in the U.S. Early diagnosis of CF means that treatments can begin immediately. Unfortunatelythere is no cure for cystic fibrosisbut proper treatment can ease your symptomsreduce complicationsand improve your quality of life. Doctors may decide that certain medications are necessary. These could include antibiotics to treat and prevent lung infectionsanti-inflammatories to lessen the swelling in your airwaysor mucus-thinning drugs to help expel mucus and improve lung function. Medications can also help improve digestive function. From stool softeners to enzymesto acid-reducing drugs. Some medications can even target the gene defect that causes cystic fibrosisaiding the faulty proteins to improve lung function and reduce salt in your sweat. Outside of medicationsairway clearance techniquesalso called chest physical therapycan relieve mucus obstruction and help to reduce infection and inflammation in the airways. These techniques loosen the thick mucus in the lungsmaking it easier to cough up. In some casesdoctors turn to surgery to help alleviate conditions that can arise from cystic fibrosis. For instancenasal and sinus surgery to help you breatheor bowel surgery to help improve digestive function. In life-threatening instanceslung transplant and liver transplant had been performed. Managing cystic fibrosis can be very complex. So consider getting treatment at a center with medical professionals trained in the disorder to evaluate and treat your condition. You can even ask your physician about clinical trials. New treatmentsinterventions and tests are constantly under development to help preventdetectand treat this disease.
Learning you or someone you know has cystic fibrosis can be incredibly challenging. It's okay to feel depressedanxiousangryor afraid. In timeyou'll find ways to copefind support and talk to others who are going through it too. Look to your friends and family to help manage stress and reduce anxiety. Seek professional help. Rememberphysical conditions come with an emotional and mental burden. And take the time to learn about cystic fibrosis. It's a complicatedsevere disorder. So don't hesitate to talk to your medical team about your questions or concerns. With the knowledge and treatment available to doctors todaylife with cystic fibrosis is better than ever before. If you'd like to learn even more about cystic fibrosiswatch our other related videos or visit mayoclinic.org. We wish you well.
Cystic fibrosis (CF) is a condition passed down in families that causes damage to the lungsdigestive system and other organs in the body.
CF affects the cells that make mucussweat and digestive juices. These fluidsalso called secretionsare usually thin and slippery to protect the body's internal tubes and ducts and make them smooth pathways. But in people with CFa changed gene causes the secretions to become sticky and thick. The secretions plug up pathwaysespecially in the lungs and pancreas.
CF gets worse over time and needs daily carebut people with CF usually can attend school and work. They often have a better quality of life than people with CF had in past decades. Better screening and treatments mean that people with CF now may live into their mid- to late 50s or longerand some are being diagnosed later in life.
Cystic fibrosis
Cystic fibrosis
In cystic fibrosisthe airways fill with thicksticky mucusmaking it difficult to breathe. The thick mucus is also an ideal breeding ground for bacteria and fungi.
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Symptoms
In the U.S.because of newborn screeningcystic fibrosis can be diagnosed within the first month of lifebefore symptoms develop. But people born before newborn screening became available may not be diagnosed until the symptoms of CF show up.
CF symptoms varydepending on which organs are affected and how severe the condition is. Even in the same personsymptoms may worsen or get better at different times. Some people may not have symptoms until their teenage years or adulthood.
People who are not diagnosed until adulthood usually have milder symptoms and are more likely to have symptoms that aren't typical. These may include repeated bouts of an inflamed pancreas called pancreatitisinfertility and repeated bouts of pneumonia.
People with CF have a higher than usual level of salt in their sweat. Parents often can taste the salt when they kiss their children. Most of the other symptoms of CF affect the respiratory system and digestive system.
Respiratory symptoms
In cystic fibrosisthe lungs are most commonly affected. The thick and sticky mucus that happens with CF clogs the tubes that carry air in and out of the lungs. This can cause symptoms such as:
- A cough that won't go away and brings up thick mucus.
- A squeaking sound when breathing called wheezing.
- Limited ability to do physical activity before tiring.
- Repeated lung infections.
- Irritated and swollen nasal passages or a stuffy nose.
- Repeated sinus infections.
Digestive symptoms
The thick mucus caused by cystic fibrosis can block tubes that carry digestive enzymes from the pancreas to the small intestine. Without these digestive enzymesthe intestines can't completely take in and use the nutrients in food. The result is often:
- Foul-smellinggreasy stools.
- Poor weight gain and growth.
- Blocked intestineswhich is more likely to happen in newborns.
- Ongoing or severe constipation. Straining often while trying to pass stool can cause part of the rectum to stick out of the anus. This is called a rectal prolapse.
When to see a doctor
If you or your child has symptoms of cystic fibrosis — or if someone in your family has CF — talk with your healthcare professional about testing for the condition. Make an appointment with a doctor who has skills and experience in treating CF.
CF requires regular follow-up with your healthcare professionalat least every three months. Call your healthcare professional if you have new or worsening symptomssuch as more mucus than usual or a change in the mucus colorlack of energyweight lossor severe constipation.
Get medical care right away if you're coughing up bloodhave chest pain or trouble breathingor have severe stomach pain and bloating.
Call 911 or your local emergency number or go to the emergency department at a hospital if:
- You're having a hard time catching your breath or talking.
- Your lips or fingernails turn blue or gray.
- Others notice that you're not mentally alert.
Causes
Autosomal recessive inheritance pattern
Autosomal recessive inheritance pattern
To have an autosomal recessive disorderyou inherit two changed genessometimes called mutations. You get one from each parent. Their health is rarely affected because they have only one changed gene. Two carriers have a 25% chance of having an unaffected child with two unaffected genes. They have a 50% chance of having an unaffected child who also is a carrier. They have a 25% chance of having an affected child with two changed genes.
In cystic fibrosisa change in a gene causes problems with the protein that controls the movement of salt and water in and out of cells. This gene is the cystic fibrosis transmembrane conductance regulator (CFTR) gene. It affects the cells that make mucussweat and digestive juices. When the CFTR protein doesn't work as it shouldthe result is thicksticky mucus in the respiratorydigestive and reproductive systemsas well as extra salt in sweat.
Changes in the CFTR gene that cause CF are divided into several different groups based on the problems they cause. Different groups of gene changes affect how much CFTR protein is made and how well it works.
To have cystic fibrosischildren must get one copy of the changed CFTR gene from each parent. If children get only one copythey won't develop CF. But they will be carriers and could pass the changed gene to their own children. People who are carriers may have no symptoms of CF or a few mild symptoms.
Risk factors
Because cystic fibrosis is a condition passed down in familiesfamily history is a risk factor.
CF occurs in all racesbut it's most common in white people of Northern European ancestry. Because it's less common in people who are BlackHispanicMiddle EasternNative American or Asianthis might lead to a much later diagnosis.
A late diagnosis may cause worse health issues. Early and effective treatment can improve your quality of lifeprevent complications and help you live longer. If you're a person of color and have symptoms that could be CFtalk to your healthcare professional so that you can get tested for CF.
Complications
Complications of cystic fibrosis can affect the respiratorydigestive and reproductive systemsas well as other organs.
Respiratory system complications
- Damaged airways. Cystic fibrosis is one of the leading causes of damaged airwaysa long-term lung condition called bronchiectasis. Bronchiectasis results in widening and scarring of the airways. This makes it harder to move air in and out of the lungs and clear mucus from the airways.
- Ongoing infections. Thick mucus in the lungs and sinuses makes a place for bacteria and fungi to live and grow. Sinus infectionsbronchitis or pneumonia are common and may happen repeatedly. Infections with bacteria that don't respond to antibiotics and are difficult to treat is common too.
- Growths in the nose. Because the lining inside the nose is irritated and swollenit can develop softfleshy growths called nasal polyps.
- Coughing up blood. Bronchiectasis can occur next to blood vessels in the lungs. The combination of airway damage and infection can result in coughing up blood. Often this is only a small amount of bloodbut rarely it can be life-threatening.
- Collapsed lung. Also called pneumothoraxthis condition happens when air leaks into the space that separates the lungs from the chest wall. This causes part or all of a lung to collapse. Collapsed lung is more common in adults with CF. Collapsed lung can cause sudden chest pain and trouble breathing. People often have a bubbling feeling in the chest.
- Respiratory failure. Over timeCF can damage lung tissue so badly that it no longer works. Lung function usually worsens slowly over time and can become life-threatening. Respiratory failure is the most common cause of death with CF.
- Bouts of worsening symptoms. People with CF may experience times when respiratory symptoms are worse than usual. These are called exacerbations (eg-zas-er-bay-shuns). Symptoms may include coughing with more mucus than usual and trouble breathing. Low energy and weight loss also are common during exacerbations. Exacerbations are treated with antibiotics. Sometimes treatment can be given at homebut a stay in the hospital may be needed.
Digestive system complications
- Poor nutrition. Thick mucus can block the tubes that carry digestive enzymes from the pancreas to the intestines. Without these enzymesthe body can't take in and use proteinfats or fat-soluble vitamins and can't get enough nutrients. This can result in delayed growth and weight loss. An inflamed pancreasa condition called pancreatitisis common.
- Diabetes. The pancreas makes insulinwhich the body needs to use sugar. Cystic fibrosis raises the risk of diabetes. About 20% of teenagers and up to 50% of adults with CF develop diabetes.
- Liver disease. The tube that carries bile from the liver and gallbladder to the small intestine may become blocked and inflamed. This can lead to liver problemssuch as jaundicefatty liver disease and cirrhosisand sometimes gallstones.
- Intestinal obstruction. Intestinal blockage can happen to people with CF at all ages. Sometimesa condition in which a section of the intestine slides inside another nearby section of the intestinelike a collapsible telescopealso can happen.
- Distal intestinal obstruction syndrome (DIOS). DIOS is partial or complete blockage where the small intestine meets the large intestine. DIOS requires treatment right away.
Reproductive system complications
- Infertility in men. Almost all men with cystic fibrosis are not fertile. The tube that connects the testicles and prostate glandcalled the vas deferensis either blocked with mucus or missing entirely. Sperm is still made in the testicles even though it can't pass into the semen made by the prostate gland. Certain fertility treatments and surgical procedures sometimes make it possible for men with CF to become biological parents.
- Lower fertility in women. Although women with CF may be less fertile than other womenit's possible for them to conceive and to have successful pregnancies. Stillpregnancy can worsen the symptoms of CF. Talk with your healthcare professional about the risks.
Other complications
- Thinning of the bones. Cystic fibrosis raises the risk of developing a dangerous thinning of bones called osteoporosis. Joint painarthritis and muscle pain also may occur.
- Out of balance electrolytes and dehydration. CF causes saltier sweatso the balance of minerals in the blood may be upset. This raises the risk for dehydrationespecially with exercise or in hot weather. Symptoms of dehydration include a fast heartbeatextreme tirednessweakness and low blood pressure.
- Gastroesophageal reflux disease (GERD). Stomach acid repeatedly flows back up into the tube connecting the mouth and stomachcalled the esophagus. This backwash is known as acid refluxand it can irritate the lining of the esophagus.
- Mental health conditions. Having an ongoing medical condition that has no cure may cause feardepression and anxiety.
- Higher risk of digestive tract cancer. The risk of cancer of the esophagusstomachsmall and large bowelliverand pancreas is higher in people with cystic fibrosis. Regular colorectal cancer screening should begin at age 40.
Prevention
If you or your partner have close relatives with cystic fibrosisyou both may choose to have genetic testing before having children. Testing done in a lab on a sample of blood can help find out your risk of having a child with CF.
If you're already pregnant and the genetic test shows that your baby may be at risk of CFyour healthcare professional can do other tests on your unborn child.
Genetic testing isn't for everyone. Before you decide to be testedtalk with a genetic counselor about the mental health impact the test results might have.
Dec. 072024