Hi I am new to this so bear with me.
I have had a chronic cough since a year last June I have been treated for asthma, silent reflux by my consultant nothing is working but wondering if Levothyroxine could be anything to do with it I have an underactive thyroid, been taking it for a few years now but just don't know what else it could be and pretty fed up now anyone else in a similar situation
How is your B12 level. I recently read an article about the connection between a persistent cough and LOW B12. I think this is to do with the nervous system. I will try and find the article !
Do you have copies of recent thyroid blood tests with ranges ? Also ensure you have the following tested - Ferritin - Folate - Iron - B12 - VitD. perhaps you have already had them done - again do you have the results with ranges. When they are posted - perhaps in a new post - lots of helpful people will comment and assist. Sundays are often quiet 
Asthma symptoms can often present when thyroid hormones are low. I am not a Doc - just someone who learns from others that know more than me
Joemais, If the cough was a reaction to Levothyroxine I think it would have presented soon after you started Levothyroxine. Take an antihistamine an hour before Levothyroxine. If the cough eases/resolves you may be a reaction to one of the fillers in Levothyroxine and should ask your pharmacist to supply an alternative make. There are 3 UK generic makes, Mercury Pharma (25, 50 & 100mcg), Actavis 50 & 100mcg (also marketed as Almus) and Wockhardt (25mcg).
If the reflux is the cause, taking an acid like HCL or apple cider vinegar before each meal will make a difference rather quickly.
Not keen on antihistamines but prefer Quercetin which lowers histamine levels, I purchase Quercetin and vitamin C complex from The Organic Pharmacy, this has helped lower my cough and general allergic reactions. It is worth googling quercetin and have a read up. Hope this helps.
What sort of a cough do you have? I had a sort of 'throat clearing' cough, where I needed to cough once every few minutes, just before I was diagnosed. It turned out I had a goitre that was right on my wind pipe, and I feel that was causing me to want to cough. It seemed exacerbated by tension because it settled down before the goitre was removed.
The cough is very wet as in very mucous I sound like some one 30 woodbines a day but I have never smoked !
Hi, I have had a chronic cough since I had my gall bladder removed 3 years ago. In searching for a cause and cure, I have discovered I am B12d, Vit D insufficient and am hypothyroid ( not that Dr agrees as doesn't recognise low FT3 levels and states can't refer to endo on NHS as TSH and FT4 are in range. Will give referral to private endo that I have asked to source). Sex hormones out of balance.
Chest X-ray was negative, asthma inhalers don't work. Respiratory guy thinks acid reflux and perhaps combo rhinitis and asthma. Prescribed PPi and wanted me to try and then would add in a different inhaler etc. All the reading I had done suggested possible link between B12d and LOW stomach acid, not high. I haven't taken PPI and bought some betaine hcl/pepsin. Cough improved when take, comes bk when don't. Breathing much better on B12 (self inject 3x weekly). Apart from walking uphill and especially when combined with hot humid conditions- was terrible last week in Italy- friends thought was going to collapse on them!
Does that all sound like you? Tend to cough when transitioning from hot to cold and on exercise. Don't know if that helps lol.
Hi Bluedragon a lot of it sounds familiar my thyroid was borderline underactive I am very tired and listless no energy, I have various asthma inhalers none have worked but still take one twice a day because the consultant said so, when I cough sometimes not often I sneeze 6 /7 times too I was told it could be silent reflux and was given metocloperamide to thin the acid down and to have the food move through my stomach quicker I cough when I have a long conversation, laughing, crying, and singing and the change in temps affects me but sometimes I can stay in 4 dys in the same temp and I still cough all day long so just though about the levothyroxine don't know as nothing is working!
Do you have high blood pressure? I found when I was taking Lisinopril for high blood pressure, I had a horrible thickly dry cough. As soon as I stopped the medication, the cough stopped. Clemmie
I havnt had Barrister but not had it checked for 6 mths this a wet cough and had it now 13 mths hence trying to see into everything inc thyroid meds
Had a lousy day today, went to our local shopping mall and in a dress shop I felt like someone had pinched my throat and I couldn't stop this loud violent cough it knocks hell out of me, taking my meds as advised but really fed up. I have bought some vit B12 and vit D see if it helps from what I have read on here otherwise guess its another trip to docs as my consultant is not till September, panicking as going away in less then a fortnight
Hi all I havnt been on here for sometime I have seen an ENT doctor and for the first time in 18 MTHS I have no longer a cough , I have gone from coughing spasms several times a day to nothing . The diagnosis and treatment I find I have silent reflux and the escaping acid has burnt my larynx causing the cough and hoarseness and of all things Gaviscon Advance has well not cured it but has made life bearable and I am over the moon I never thought I would ever be right again hope this helps someone
Thanks so much for posting this, I will give it a go. I could see that reflux, hypothyroidism and chronic cough are linked from research, mine coincides with a heavy feeling in the chest and a wheeze at the end of the cough which sounds like a smoker, though I have never smoked.
I will try the Gaviscon and keep on with the Betaine, though Betaine is difficult to swallow with a reflux burnt gut.
Hypothyroidism and hunger
Hypothyroid with dizziness and balance problems; swollen lips and dry mouth. 
A strange cough and palpitations
DRY COUGH, NO CONGESTION AND VIOLENT COUGHING
