Signs and Symptoms of Cystic Fibrosis

CF develops in most patients in the first year of life. Usually at least some symptoms are present at birth, although sometimes symptoms do not appear until adolescence. About 3% of all CF patients are not diagnosed until adulthood.

The lungs and pancreas produce the most common symptoms, usually respiratory and gastrointestinal complications. Most CF patients eventually die from advanced lung disease. CF also affects, to a lesser extent, the reproductive tract and the sweat glands.

Respiratory Symptoms of Cystic Fibrosis

Almost all CF patients begin to experience respiratory symptoms within the first couple of years of life. They include:

  • Repeated infections: The accumulation of sticky, thick mucus in the lungs creates a favorable environment for infectious microorganisms to inhabit and flourish.
  • Chronic cough: Patients with CF often have a persistent cough that results from repeated respiratory infections. Over time, patients begin coughing up a viscous (thick, sticky), purulent (pus-filled), green-colored sputum.
  • Recurrent bronchitis: The repeated infections that afflict the lungs of CF patients often lead to bronchitis, inflammation and swelling of the bronchi that obstructs the airways and stimulates the production of mucus. The bronchitic mucus creates yet more obstruction and further increases the chances of infection.
  • Recurrent pneumonia: Pneumonia is a lung infection that can be caused by a number of microorganisms. Patients with CF are especially susceptible to pneumonial infections because the abnormal mucus and reduced water content in the airways promotes bacterial growth.
  • Bronchiectasis: Continual respiratory problems can eventually lead to bronchiectasis and permanent lung damage, which is the usual cause of death for CF patients. Bronchiectasis is the chronic dilation of the airways. The enlarged airways become filled with mucus, which makes them prone to more infection, enlarging and damaging them even more. The damage caused by bronchiectasis is permanent, and patients usually cough up a great deal of infected mucus.
  • Pneumothorax: Pneumothorax is the trapping of gas or air between the lung and the chest wall that occurs as a result of a leaky lung or rupture. More than 10% of all CF patients experience pneumothorax.
  • Hemoptysis: Hemoptysis is the coughing up of blood and is a symptom of many different underlying disorders, including cystic fibrosis. Minor hemoptysis is common in CF patients with advanced lung disease.
  • Digital clubbing: Digital clubbing is enlargement and bulbous, shiny appearance of the ends of the fingers and toes. It occurs in nearly all CF patients who have advanced lung disease.
  • Cor pulmonale: Cor pulmonale is an enlargement of the right side of the heart caused by a high resistance to blood flow through the lungs. It is often a prominent feature in patients who have advanced lung disease and leads to heart disease.
  • Sinusitis: Sinusitis is inflammation of the nasal sinuses. The sinuses are hollow cavities inside the skull that produce mucus and help keep the nasal passageway moist. Chronic sinusitis is common in children with CF and can lead to nasal obstruction and a runny nose.
  • Allergic bronchopulmonary aspergillosis: Sputum is the substance that is expelled when someone coughs or clears his or her throat. Nearly half of all CF patients have a fungus known as Aspergillus fumigatus in their sputum, and about 10% develop a condition known as allergic bronchopulmonary aspergillosis. Aspergillosis is an infection in the bronchi or lungs that can lead to the formation of inflammatory lesions.
  • Nasal polyps (nasal polyposis): Nasal polyps are fleshy growths inside the nose. Nasal polyposis occurs in about 15% to 20% of all CF patients and often requires surgery.

Gastrointestinal Complications of Cystic Fibrosis

In CF patients, nearly all of the pancreatic tissue is destroyed because of the disturbed ion transport, creating a multitude of problems related to pancreatic dysfunction. Symptoms related to pancreatic insufficiency, especially poor weight gain and bulky, foul-smelling stools, are experienced in over 90% of all CF patients.

In the intestines, the epithelial cells are not able to flush away all of the various secretions and macromolecules from the intestinal crypts (pits in the intestinal epithelium), eventually causing obstruction in both the small and large intestines.

Pancreatic complications and intestinal obstruction can manifest in a variety of ways, including:

  • Poor weight gain and growth, also known as "failure to thrive": Babies and children with CF have a difficult time gaining weight, even those with a hearty appetite, because the pancreas is not absorbing and digesting fats and fat-soluble vitamins (vitamins A, D, E, and K).
  • Greasy, foul-smelling stools (steatorrhea): All of the fat that the pancreas is not adequately digesting and absorbing is passed out of the body in the stools, which take on a greasy appearance and smell very bad. Fat-soluble vitamins are flushed out of the body in the stools, and in severe cases, a patient can suffer complications due to fat-soluble vitamin deficiency (e.g., visual disturbances due to a lack of vitamin A).
  • Meconium ileus: Meconium is the term given to a newborn's first stools, which are usually thick, sticky, dark green, and odorless. Ileus refers to an obstruction of the intestines. In babies with meconium ileus, the bowel is blocked with very thick meconium resulting from a deficiency of enzymes, including trypsin, that are normally secreted amply by the pancreas. Meconium ileus occurs in about 10% of all newborns with CF. Its symptoms include emesis (vomiting) and the inability to pass stool.
  • Distal intestinal obstruction: Distal intestinal obstruction, also known as meconium ileus equivalent, is a syndrome that occurs frequently in children and young adults with CF and, because of its symptoms, is sometimes confused with appendicitis. Symptoms include pain in the right lower quadrant, a loss of appetite, and emesis (vomiting). Distal intestinal obstruction results from blockage by poorly digested fats (and proteins) which have clumped into a mass of firm sticky material.
  • Hyperglycemia: Hyperglycemia is a high blood sugar that results when the body does not have enough insulin to convert sugar (specifically glucose) into energy. Patients with hyperglycemia usually are very thirsty, have a dry mouth, and need to urinate often. The pancreas is the organ responsible for producing insulin. Only a small percentage of CF patients develop hyperglycemia, and if they do, it usually does not appear until they are in their 20s or 30s.
  • Abdominal discomfort: The belly is usually swollen with gas and the patient feels abdominal discomfort.
  • Rectal prolapse: Rectal prolapse is a condition in which the lining of the rectum pushes out through the anus. It usually occurs during a bowel movement. This is a well-recognized but rare complication in young children with CF.

In the hepatobiliary system (the liver and the secretions from the liver), which is damaged in about 25% to 30% of all CF patients, malfunctioning secretion can cause liver disease and gallstones, leading to pain and jaundice (yellowing of the skin):

  • liver disease (liver cirrhosis): Liver complications include a fatty liver, which usually doesn't create problems except in infants; focal biliary fibrosis, which causes the liver to first enlarge and then shrink like a typical cirrhotic liver – this is caused by blockage of the bile ducts, which leads to inflammation, which leads to fibrosis; and development of cholesterol gallstones.
  • prolonged natal jaundice: Prolonged natal jaundice, also known as prolonged obstructive jaundice, is a yellowing of the skin and mucous membranes caused by excessive amounts of bile pigments in the blood. Normally, bile pigments are filtered through the liver and excreted in the feces. When the ducts connecting the liver to the intestines are blocked, obstructive jaundice develops.

Reproductive Tract Complications of Cystic Fibrosis

Reproductive tract abnormalities that people with CF often experience include:

  • Delayed puberty: Puberty is often delayed a couple of years in both boys and girls with CF. The delay is probably due to nutritional inadequacies.
  • Male infertility: Azoospermia is the absence of sperm in the semen. More than 95% of men with CF are azoospermic due to an obliterated vas deferens (the tube in the male reproductive tract that carries the sperm from each testis to the urethra).
  • Female fertility complications: About 20% of women with CF are infertile. Female infertility is due to the effects of chronic lung disease on the menstrual cycle, as well as a thick cervical mucus that blocks the migration of sperm.

Sweat Gland Complications of Cystic Fibrosis

Patients with CF secrete normal amounts of sweat, but the sweat has abnormally high levels of salt (NaCl) due to the malfunctioning Cl- transport, causing very salty skin. Indeed, the symptom is nearly universal and the sweat test is used as the number one diagnostic test for CF. Only about 1% to 2% of all people with CF show normal sweat test results.

The imbalance of salt in the sweat can lead to abnormal heart rhythms.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 01 Jun 2000

Last Modified: 10 Jun 2011