What is Cystic Fibrosis?

Cystic Fibrosis is a genetically inherited condition affecting primarily the lungs and digestive system. It is a condition in which you are born with, and can not develop in later life. It is also not contagious. (Yippee!)

There are over 10,800 people in the UK who have it.  But how did this come to be?

Well this is where a quick science lesson is necessary.  First of all both parents are carriers of the defective gene which causes CF.  This means there is a 1 in 4 chance of having a child with the condition.  There is a 50% chance that the child will be a carrier, a 25% chance that the child would not be affected at all and 25% that they could have CF.  Typically, I drew the short straw, whereas my brother does not have CF, (lucky sod!) but could be a carrier.  In fact 1 in 25 people actually carry the faulty gene without even knowing!

Does that make sense so far? Excellent.

If science just ain’t your thing then you can skip this part.

If you jog your mind back to biology class, you’ll remember that everyone has 46 chromosomes which is split into 23 pairs.  Half is from mum and the other half from dad.  Simples.  Now the CFTR gene, (also known as CF transmembrane conductance regulator, but we’ll stick with CFTR for now) which is involved with causing the symptoms of CF is interestingly found on chromosome 7. This means you need to inherit two of the faulty genes (one from mum, one from dad) to have CF.  However if someone only has one CFTR gene, then they will not have CF but they will remain a carrier who can pass that onto their child (depending on their partners gene status…best not to ask this one on the first date!)

So you might be thinking, two genes make someone with CF.  No, it doesn’t stop there… What if I told you there are over 1400 different strains of the CFTR gene? That’s quite a lot.  That’s more selfies than are on my phone.  Anyway, even though most of them are pretty rare, the most common one is the Delta F508 (All my DF508 fam say hell yeah!) So as we know CFers have two CFTR genes but that doesn’t mean they are the same mutation.  The different combinations can create different symptoms of CF.  But there are so many possibilities it’s almost impossible to predict the exact way in which CF will affect you.  And this is why the symptoms in each person with CF is different.  Voila! We are all unique.

The Lungs

Moving onto the lungs.  The basics, is that CF people are constantly producing sticky mucus which is difficult to shift from the lungs.  If left unattended, it can cause many problems the worst of which is a chest infection (or Exacerbation if you speak medical) which can, over time, cause damage to the lungs.

Mucus is normally watery and thin which is produced by cells in the airway lining.  It’s main objective is to defend the lungs from attack from bacteria or viruses etc.

The airways in the lungs are lined with tiny hairs called Cilia whose main job is to keep the airways clear of mucus, bacteria and dust which is achieved by the hairs moving back and forth. This then allows the mucus to be pushed up the airways and coughed up or swallowed. However someone with CF has a layer of sticky mucus lining the airways, therefore trapping the cilia beneath it.  Because it can’t move properly, the mucus can capture dust particles or bacteria that’s breathed in and can cause infections to grow.

There are multiple ways of thinning the mucus to help clear the lungs.  There are tablets, inhalers and nebulisers as well as other devices.  Also daily physiotherapy is essential to keeping the lungs as clear as possible, even though it is time consuming.


The other most prominent part to CF is problems with digestion.  To put it simply, we can’t break down the fat in food/drink.  So we need tablets called creons (not to be mistaken for crayons…two very different things) with every food or drink that contains fat.  So how many creons taken really depends on how much fat is in said food/drink about to be consumed.

Creons come in different strength, from 5,000 to 40,000 units of lipase (the enzyme that digest fat).  Getting the dose right for each meal is imperative. Too much or too little can result in weight loss or prevent weight gain and it can also cause unpleasant bowel symptoms.  And trust me, that ain’t nice!

And the science behind it?  The pancreas has two main priorities, the first to produce enzymes and the second to produce insulin.  The pancreatic juice, which contains the enzymes to break down fat, protein and carbohydrates, is an alkaline fluid which travels along the pancreatic ducts and neutralises the stomach acid.  In CFers, the ducts are blocked with mucus therefore preventing the enzymes to reach the digested nutrients.  This means that it can’t be broken down and absorbed properly, and can contribute to malnutrition, weight loss, physical weakness etc. It also means that the vitamins can not be absorbed which can lead to all sorts of madness!  Most CFers take vitamin supplements.

Fortunately, there are also supplements to replace the lack of enzymes which are the creon.  The coating of the creon is designed to pass freely through the stomach without being dissolved in the acid.  It is actually broken down in the first part of the small intestine (duodenum) where the food is digested.  Quite clever really.

Also the insulin in the pancreas stops working properly as the ducts are blocked with enzymes.  Over time this could increase the risk of developing CF related diabetes.

It is also important to mention that not everyone with CF has a dodgy pancreas (or pancreatic insufficient!).  Like I say, we are all very unique!

So those are the main areas affect by Cystic Fibrosis.  Of course the chaos doesn’t stop there.  Other complications which may arise are:

  • Joint pain and Arthritis
  • Bone disease and Osteoporosis
  • Sinusitis
  • Nasal Polyps
  • Liver Disease
  • Mental Health
  • Acid Reflux
  • Fertility
  • Gastro-oesophageal reflux disease (GORD)
  • Distal intestinal obstruction syndrome…

…I mean, the list goes on…

What a time to be alive! 😉


If you fancy donating a few bob to the CF trust, then you can do that here. If you want to broaden your knowledge on the CF world, you can here.  

If none of the above makes no sense and you prefer watching a video about ‘CF explained’ then you can here…