<s>[INST] Hi, I have an under active thyroid and take 100 mg daily. Presently I am getting dizzy spell light headed, thirsty, soreness around inside of lips.... feling tired alot also even though getting decent sleep... have tree children 6 4 and 14 months. wondering should i be concerned or will symptoms ease. thanks Imelda [/INST] Hello, If it's been awhile since you've had your thyroid checked then, I would recommend not only a TSH but also an FT4 to see if the amount of replacement you are taking is truly adequate for your needs.  I would also look at a HbA1C and fasting blood sugars to screen for possible prediabetes or diabetes itself. Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor.  </s>