How CF affects the body

While people with CF may look outwardly healthy, they are living with a life-limiting condition that affects their body in many ways. CF is a complex condition, however, and people with CF may experience a difference in the severity of symptoms compared to others.

A change to a gene (called the CFTR gene) that regulates how cells move salt and water around means that the body’s mucus become very sticky and thick. This mucus builds up in the lungs, airways and digestive system, affecting breathing and digestion for people with CF.

Symptoms that people with CF may experience include:

  • a persistent cough that sometimes produces thick mucus
  • difficulty breathing
  • wheezing
  • frequent lung infections
  • salty sweat – salt loss in hot weather may produce muscle cramps or weakness
  • tiredness, lethargy or reduced ability to exercise
  • poor growth or weight gain
  • frequent visits to the toilet
  • poor appetite
  • CF-related diabetes
  • infertility in males

The lungs

In healthy lungs, a thin layer of mucus lets the body trap dirt and bacteria so that the body can move them out of the lungs.

For people with CF their mucus is much thicker and stickier and it can clog the lungs and airways. This mucus is hard to clear from the lungs, so it can trap bacteria which can lead to lung infections. Persistent coughing is common among those with CF.

People with CF may have reduced lung function due to the thickening of the walls of the airways, narrowing of the airways, damage to the airways and obstruction of the airways with mucus.

The digestive system

The pancreas produces digestive enzymes which help the body digest food by breaking down fats, proteins and carbohydrates.

The thick mucus that people with CF have blocks the ducts that carry the enzymes from the pancreas to the digestive system, causing what is known as pancreatic insufficiency. People who are pancreatic insufficient need to take enzyme medications to assist their digestion.

People with CF have difficulty in digesting fats which makes it harder to maintain weight. They need a diet that is higher in fats and higher in kilojoules to compensate for this. They may also experience greasy and bulky stools and difficult bowel movements.

About one-third of all people with CF also are affected by a form of diabetes called CF related diabetes (CFRD), where their mucus prevents the pancreas from producing enough insulin. CFRD can be managed by monitoring blood-sugar levels and through using insulin.

Other symptoms

Chiefly among other symptoms, cystic fibrosis can affect bone density, the liver and cause fertility problems in both women and men.