during the month of ramadan , muslims from all over the world abstain from food and fluid intake from dawn ( sehr ) to sunset ( iftar ) for 1 month . this prolonged fasting causes several minor metabolic and hormonal changes in the body . which rarely cause any problem to a healthy individual . however , problems do arise in certain chronic diseases like diabetes mellitus , and thus , patients are advised to consult their physicians before planning to fast . in patients with thyroid diseases , so far there are minimal data suggesting any adjustment in the treatment during ramadan . in ramadan , minimal changes are observed in the levels of t3 , t4 , and tsh in a normal person . few studies have shown that t4 decreases significantly during fasting in ramadan in both genders , while tsh increases significantly in male subjects , although tsh and t4 levels stay within the normal ranges . there is a positive correlation between t4 changes and number of days of fasting in women . most of these changes revert back to pre - ramadan levels once fasting is over . whether primary or secondary , thyroxine and its levo - isomer ( levothyroxine ) are the most widely available option for thyroid replacement . thyroxine is taken usually orally ( empty stomach ) as recommended , as food / medications ( cholestyramine resin , sucralphate , iron sulphate , calcium preparations , aluminum antacids , raloxifene , activated charcoal , various soya products , and food and herbal remedies ) affect its absorption.[58 ] also a fiber - enriched diet , the traditional south asian diet , and coffee in early morning may also interfere with the absorption of levothyroxine . the amount absorbed decreases from 80% in the fasting state to 60% in the fed state . so , when taken with food , the absorption of levothyroxine is incomplete , resulting in variable and higher tsh levels . standard drug information resources recommend that levothyroxine should be taken half an hour before breakfast on an empty stomach , to prevent interference of its intestinal uptake by food or medication . while taking thyroxine in between / with food might not be best , due to variable reasons , taking it at bedtime is another option , as it has shown to have almost the same effect as when taken on an empty stomach . whether primary or secondary , thyroxine and its levo - isomer ( levothyroxine ) are the most widely available option for thyroid replacement . thyroxine is taken usually orally ( empty stomach ) as recommended , as food / medications ( cholestyramine resin , sucralphate , iron sulphate , calcium preparations , aluminum antacids , raloxifene , activated charcoal , various soya products , and food and herbal remedies ) affect its absorption.[58 ] also a fiber - enriched diet , the traditional south asian diet , and coffee in early morning may also interfere with the absorption of levothyroxine . the amount absorbed decreases from 80% in the fasting state to 60% in the fed state . so , when taken with food , the absorption of levothyroxine is incomplete , resulting in variable and higher tsh levels . standard drug information resources recommend that levothyroxine should be taken half an hour before breakfast on an empty stomach , to prevent interference of its intestinal uptake by food or medication . while taking thyroxine in between / with food might not be best , due to variable reasons , taking it at bedtime is another option , as it has shown to have almost the same effect as when taken on an empty stomach . during the month of ramadan , changes in gastric motility ( due to prolonged fasting ) , interference with heavy meals , possible alteration in the circadian rhythm and the effect of the deiodinase activity might alter the metabolism of the drug in the body . based on the above information , it can be postulated that during ramadan , the proper administration of thyroxine / levothyroxine is achieved if it is taken half an hour before sehr . but most of the patients find it difficult to wake up that early and either miss the dose or take it with the meal . this problem can be easily managed , if levothyroxine is taken at bedtime , which too has an almost identical lowering effect ( if not better ) on tsh . the effect may be due to the better effect of factors such as gastric motility , heavy meals , circadian rhythms , and effect of deiodinase activity.[1619 ] as people revert back to their usual routine / habits after ramadan , it seems more logical to go back to their routine ( as before ramadan ) after the ramadan comes to an end . based on our current knowledge of thyroid replacement regimens warning signs in a newly diagnosed or untreated thyrotoxic patient include the development of polydipsia , dehydration , diarrhea , and tachycardia , which would further worsen in the case of prolonged fasting . patients with mild symptoms of thyrotoxicosis usually have no trouble in fasting but , those with severe symptoms can land into troublesome dehydration and diarrhea . quran ( the holy book of muslims ) has given clear exemption to the sick people from the fast during illness but they need to compensate for the missed days of ramadan later . patients can also be advised to discuss with a local religious scholar for such issues . the use of thionamides like methimazole , carbimazole , and propylthiouracil ( ptu ) is effective in patients with hyperthyroidism . they are actively transported into the thyroid gland where they inhibit both the organification of iodine to tyrosine residues in thyroglobulin and the coupling of iodotyrosines . warning signs in a newly diagnosed or untreated thyrotoxic patient include the development of polydipsia , dehydration , diarrhea , and tachycardia , which would further worsen in the case of prolonged fasting . patients with mild symptoms of thyrotoxicosis usually have no trouble in fasting but , those with severe symptoms can land into troublesome dehydration and diarrhea . quran ( the holy book of muslims ) has given clear exemption to the sick people from the fast during illness but they need to compensate for the missed days of ramadan later . patients can also be advised to discuss with a local religious scholar for such issues . the use of thionamides like methimazole , carbimazole , and propylthiouracil ( ptu ) is effective in patients with hyperthyroidism . they are actively transported into the thyroid gland where they inhibit both the organification of iodine to tyrosine residues in thyroglobulin and the coupling of iodotyrosines . thyrotoxicosis includes hyperthyroidism ( excessive hormone production by thyroid ) as well as thyroiditis ( inflammation of the thyroid gland ) . the mainstay of treatment for patients suffering from thyroiditis remains nsaids , steroids , or beta - blockers , and it remains a self - limiting condition . the management of this disorder during ramadan depends on the severity of symptoms . in the treatment of hyperthyroidism , propylthiouracil has a limitation during ramdan due to its required dosing of every 46 h. the other most commonly used antithyroid drug  methimazole  has a fairly long duration of action , and can be taken at any time of the day in a single or divided doses . for that reason , in ramadan , no treatment adjustment is needed in these patients and they can be monitored on the standard protocols . the carbimazole dose required to yield an equivalent dose of methimazole is approximately 40% higher . for example , a 10 or 20 mg dose of carbimazole yields roughly 6 and 15 mg of methimazole , respectively . this drug takes a week to show its maximum effect and thus it is added with beta - blockers for quick symptomatic control . if the treating physician is considering alternate treatment options like radio - active iodine or surgery , these can be delayed till the completion of ramadan for the said reasons . although there are essentially no data on the adjustment of treatment protocols of patients with thyroid diseases , we have proposed that hypothyroid patients can take their thyroxine at bedtime easily instead of half an hour before sehr . for hyperthyroid patients , the preferred oral antithyroid treatment is methimazole , which can be taken once or twice daily in ramadan easily .
in the month of ramadan , patients with thyroid diseases , most of the time , do not need treatment adjustments and can fast safely without any health hazards . 
 patients with hypothyroidism taking thyroxine can take their tablets on an empty stomach at bedtime instead of half an hour before sehr . 
 patients with hyperthyroidism , on methimazole / carbimazole can continue their dose in once or twice daily regimes , while those on propylthiouracil need to be switched . 
 hyperthyroid patients with severe symptoms should start treatment immediately and can avoid fast for few days after a consultation with their religious scholar .