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.
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.
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.