hi welcome to our site read your query that is a very significant question and i appreciate your problem i will try my best to answer your query there are a huge number of causes for this come winters and probably one reason is that i think your fluid intake has probably reduced i would also suggest cbc, kft, ecg, echo fbs and tsh to rule out other possible causes any other symptom? i hope this helps you inform the reports mentioned above (if any) so i can be of help further best of luck (please do understand that some problem remains as online texting cuts down history and examination thereby reducing the effect and efficiency and increases reliance on tests) (If the answer has helped you, please indicate this) dr.saumyamittal@gmail.com