I think it is from having to much thryroid in me before I knew what was wrong I cleared throat all the time, Not until my neck swelled did I know anything was wrong. I have been working with getting right dose of med. for 8 yrs. now either to high or low. I switched to Levothroid .137 because Sny. .125 still felt tired, now clearing throat and not sleeping good at night. So I started cutting off little tiny piece for past 4 days, and throat clearing as stopped and sleeping much better, Waiting for dr. to see if I can alternate .125 one day and .137 next, maybe that will work, also you need to know if you go for blood work dont take your pill till after blood work is taken or it will show normal please email if any questions.Julia