Log in
Asthma UK community forum
12,192 members18,122 posts

Anyone been checked for Cystic Fibrosis?

Hello all,

I'm just starting the process of being checked for Cystic Fibrosis.

I don't have bronch (my lungs are actually in pretty good nick according to chest CT), but I do have crappy mucus-led asthma, and now have brittle Type 3c diabetes, general pancreas crapness and some GI problems. I've always been small and skinny, get a lot of chest and sinus infections and can't deal with having much fat in my diet. I also have an oropharangeal candidiasis which has been with me for nine months now... though it is less rampant now my diabetes is being treated.

I also have a few other obscure symptoms that I won't go into because it would be way TMI, but they're also possibly CF-related.

So... I tick a lot of boxes in terms of phenotype (symptoms).

On the other hand, I feel like my symptoms aren't 'bad enough' for it to be CF. Though I have to remind myself that I'm on about 20 different meds to control them! I also realise that I've 'normalised' a lot of my stuff - I guess we all do that? My BMI goes between 16 and 19, so when it's over 17 I feel like it's not bad at all, but I realise that this is still lower than many people with CF.

Anyway, I've had my first sweat test, and my bloods are off being checked for the typical CF genetics.

My understanding is that, based on both of these, they then sort you into one of 3 piles: Definitely CF, CF likely and CF unlikely. If you're in the likely/unlikely pile then they make a clinical judgement, or follow you up for a while to see how things go.

In many, many ways it would make my life easier if I get the diagnosis - I'm on most of the drugs they use anyway, and it would bring my resp, GI, diabetes and rheum care all under one team. They might add in a couple more drugs that would also improve life. The also run home IVs and so on, which would be really good as I've spent 30 nights in hospital since xmas and I'm fed up of it.

I'm just wondering if anyone else has been through the process, and how you found it? The CF team are amazing - have been totally lovely. I feel so odd to be sat here hoping that I have it, but having an explanation that draws everything together, and specialist treatment that isn't all fragmented would be so helpful.

Any experiences you can share? I am feeling a bit lonely about it!


13 Replies

Hello again :)

Yes, I have been checked for CF, both the sweat test and genetic screening which was negative. Its part of the workup that Papworth do for all new chest patients. I was kinda gobsmacked when they said it, but they explained that they do pick up adults with CF by doing this - who have muddled along okayish but with chronic issues, just not necessarily severe enough that someone has considered CF. The sweat test is the 'gold standard' for CF testing.

I was quite anxious about it, as like you I have always been very underweight, struggled with fatty foods and crap lungs, but was rather relieved not to be positively tested!

For what its worth, while I can understand that you feel life would get easier in some ways, I sincerely hope you don't have it. If you went to Papworth, you could get home IV's without needing to have CF ;)

the CF foundation has more info on testing:


Lynda x


So... my first sweat test came back in the 'equivocal' (maybe) zone. Values within the zone occur equally in people with known CF, so if you're in that zone it's largely irrelevant what the actual number is. So it wasn't a strong positive (we'd have been surprised if it was) but it wasn't negative either.

I have to have a second sweat test on Monday, as they're a bit unreliable. I also realised I'm on a low-sodium diet (because I use potassium salt as I'm prone to low potassium with the beta-agonists) - rang them and they said that might suppress my value but it'll be taken into account when they look a the whole picture.

My genetic tests will come back in about another 10 days.

Of people who test in the 'equivocal' zone in the sweat test, 1 in 4 have CF. Which of course isn't the same as general population as only people with either the phenotype (symptoms) or a genetic link get tested.

I'm lucky that the hospital I'm under is one of the world leaders for CF - they actually produce 'the book' on diagnosis and management. According to their website, the diagnosis is still made clinically where it's not confirmed by sweat test or genetics. Both of these can confirm but not rule-out CF.

So I guess I'll need to have some cough-into-this-jar tests and so on as well if my genetics aren't clear cut.

It used to be thought that either your electrolyte stuff worked (not CF) or it didn't (CF) but apparently they now realise that there's a spectrum with most people at the not-CF end, 1 in 2500 (ish) at the CF end and a proportion of people floating about in the middle, who need a clinical diagnosis, or close follow up with the diagnosis left explicitly as 'possible CF'.

I do tick a silly number of boxes on the phenotype. But then it's always hard to know what 'normal' is (I have no idea how thick other people's mucus is!) - and how much good-management of your health so far has seen off the complications.

I had a very bad chest-infection at 15 that took multiple rounds of abx to shift, and got me my formal dx of asthma, and I'm allergic to penicillin and erythromycin, so my GPs have always gone for early-and-strong abx if I present with a chesty cough or asthma exacerbation with suspicion of infection. I used to have 3 nasty chest infections every year, but since moving to the middle of nowhere and basically limiting my exposure to infection that has gone down to 1 or 2. Last year I read the 'abx make no difference to most coughs' info, persisted with a cough for over six weeks to no avail and then it turned the corner within a couple of doses of abx. Even when I don't have obvious signs of bacterial infection, doxycycline seems to make a difference.

Apparently the incidence of bronchitis in the total population is 1/20 per year. So - at nearly 40, I should have had it twice. So on paper I've had 20 or 30 times as many chest infections as I 'should' have, but of course it doesn't work like that. And I know many people with bad asthma have even more than that, so it always feels like I've got away without that many - especially since very consciously controlling my exposure.

Sorry... just spilling my thoughts here as it helps. I'm feeling a bit unsettled by it all. My own GP is on maternity leave and her locum is lovely but a stranger really. Also I need to realise that having emotions is not an illness ;) (Aspergers in action there).



I hope you get a clearer answer soon. TBH, gastro part aside, Im not sure what difference testing positive would have made to my treatment, as Im still treated aggressively with IV antibiotics at the first signs of things being iffy. I guess the only difference is I can cope without being on a mucolytic (Im supposed to be on it, but it increases my reflux ten fold which isn't great when you are prone to aspiration!). Like you for most of my life, three or so chest infections a year was pretty much the norm. I don't produce sputum now, as they just don't let me get to that point anymore. Up until I got swine flu and pneumonia - the one time I was almost ventilated in ITU, I always produced loads with infections, as I did with the pneumonia. But my lung function is too poor now to let things get to that point. It disappoints the physio's who are keen on collecting their little pots! ;)

Don't apologise for ruminating out loud if it helps, Im not surprised you feel unsettled - it was probably the test that frazzled me the most because of the implications. It can feel a long time to wait for answers! And even the non Aspergery ones of us sometimes need to remember that having emotions - and displaying them is healthy! ;)

Im having to change my GP shortly as we are moving near to Nottingham. I am really very upset and worried about it, he has been my GP for 15 years and is fantastic, he knows me really well and there is mutual trust. I can count on one hand the times I have had to see another GP in that time. Ugh. I've told him Im not happy LOL. A good GP makes such a difference to your care, particularly with multiple health issues eh x


Like NurseFurby, I am a Papworth patient (hello!).

I have been tested for CF several times, and I do have severe bronchiectasis. My sweat tests have all been borderline, and high borderline at that ( sodium at 55 and 58 on the two tests, where 60 is positive). Papworth did a genetic test for the most common 40 mutations but none were found. Because of my condition, they then sent my genetics off for a full screen in USA, which took ages as they test for every known mutation so far recognised worldwide. None were found, so it is concluded that I don't have CF. Of course, the possibility remains that I have hitherto unrecognised mutations, but for me to have not one but two entirely unknown mutations seems so vanishingly small that it is not worth considering.

As you say, it would simplify things considerably to get a positive diagnosis. However, I have found that receiving my treatment at a hospital that is also a CF centre, with the same consultants, has enabled me to access all the treatments and tests that I would need were I to be CF, so it is immaterial really. If I need a treatment, or a drug would help, or a physio technique that is more usually used in CF but is thought might be helpful to me, I trial it.

Hope you get some resolution soon.


How are you doing now Carrie? :)


Hopefully coming to the end of another long (6 weeks) admission to Papworth!

Been long and hard as was pretty poorly when admitted - on constant bipap for a couple of weeks with an infection that just wouldn't respond to the antibiotics, although they kept swapping them round. Fortunately, something did it and things turned round, although I have had a few serious conversations with the consultants and got some tricky decisions to make, hey ho. Hopefully home next week - yippee!


And you?


Oh bless you, I'm sure it's not that long since your last admission! Was up on ward a few times this month visiting a friend - backwards and forwards as on home IV's, but escaped admission. :) glad things have improved, hope you do get to go home soon!


Maddie has had 2 sweat tests and genetic testing for CF as seemed to show all the traits. All came back negative thank goodness.

We do use saline nebs and physio as would be used with CF and she does react to this positively.

I find the blur between chronic asthma and CF confusing and the cross over of treatments. Maddie certainly responds more to the nebs and physio than to the normal asthma treatments.


Thanks everybody :)

I had my second sweat test yesterday. Should get that back on Thursday and then genetics should come back next week.

I feel a bit of a fraud as my asthma is pretty well controlled these days, and I've never needed HDU or ICU - but the main reason they're looking at it now is because of the issues with my pancreas.

Carrie - I hope you escape soon! As you say, the access to expertise and treatment is much more important than the label. I'm hoping that if I'm inconclusive they might take the 'wait and see' approach and keep me under their team at least for a little while.

Emily - I think the problem is that Asthma is a 'bucket diagnosis' - and it's based on a cluster of symptoms. Anyone who has chronic restrictive breathing problems, which are reversible using bronchodilators, with or without extra sputum due to allergy or inflammation, is chucked into the 'asthma' bucket, because that gives the best basis for treatment that we currently have. I expect that before Maddie reaches adulthood the asthma bucket will get subdivided into many smaller buckets. It already is, to a certain extent - allergic / not allergic etc, but the divisions are still quite crude and very much based on symptoms and triggers rather than actual physiology. With CF, they know that the defect is impaired production and use of a specific protein - I can't wait til we know this much about asthma(s)!

Generally, postural drainage and physio and mucus thinners are useful for anyone who doesn't consistently have the strength to cough up their mucus otherwise. That can be due to the mucus being extra thick or there being a lot of it, or due to lack of diaphragm strength, or generally poor lung capacity / function, or coordination difficulties. Most people with CF have the super-sticky mucus, but small children without CF will generally be less strong and less coordinated in terms of their coughing than older children and adults, so the threshold for them needing to use the techniques and drugs that make that easier is lower. It sounds like the physio and mucus thinners are helping Maddie anyway, so that's good!


Hey -

Was just reading this and saw that a few of you are under papworth! I am currently struggling under the care of Addenbrookes and was just wondering what it was that led you to get a referral there? I am so not happy with how disjointed my care is and how random a lot of it is, very little consistency and continuity. I know the CF services at papworth are amazing, as are the other respiratory services they offers and I wish I could get that level of care and support!

Kirsty x


Hi Kirsty, my GP referred me as both he and I were unhappy with the respiratory care I was getting at the local hospital.

If you're unhappy, ask for a referral but I don't know if they see people who just have asthma. I go to their lung defence clinic:


Hope that helps :)


Does your sweat tastes like salt


You may also like...