Cystic fibrosis is caused by a faulty gene that a child inherits from both their parents.
The faulty gene means that some cells struggle to move salt and water across the cell wall. This, along with recurrent infections, can result in a build-up of thick, sticky mucus in the body's tubes and passageways particularly the lungs and digestive system.
The condition is present from birth and cannot be caught from someone else who has it.
Genes come in pairs. You inherit one set from your mother and one set from your father.
To be born with cystic fibrosis, a child has to inherit a copy of the faulty gene from both of their parents.
This can happen ifthe parents are "carriers" of the faulty gene. This means they don't have cystic fibrosis themselves, but they can have a child with the condition if their partner also carries the faulty gene.
It's estimated that around 1 in every 25 people in the UK are carriers of the faulty gene that causes cystic fibrosis.
If both parents are carriers, there's a:
This is known as an autosomal recessive inheritance pattern.
Cystic fibrosis is an inherited condition in which the lungs and digestive system can become clogged with thick, sticky mucus. Read about the symptoms, causes and treatments.
Cystic fibrosis can cause a range of problems. The lungs and digestive system are the main areas that are affected.
Cystic fibrosis is caused by a faulty gene that a child inherits from both their parents. The condition is present from birth and cannot be caught from someone else who has it.
Read about the tests that may be carried out to diagnose cystic fibrosis, including newborn screening tests, the sweat test and genetic testing.
Read about the main treatments for cystic fibrosis, including medications, airway clearance techniques, nutritional advice and lung transplants.
Lauren, 14, talks about living with cystic fibrosis and how she doesnt let it stop her from doing the things she loves.