I have a problem with terrible hot flashes at night. i am not menopausal, according to my obgyn. could lithium or levothyroxine cause this trouble?

Rare: So far only 33 people have reported night sweats on lithium to the fda. 315 people reported the same side effect, night sweats, on levothyroxin. It is therefore rare with both given the significant number of people in the United States that take these medications. I think would be reasonable to have your thyroid rechecked because excessive or over correction of your thyroid with levothyroxin can cost night sweats if you are in the hyper thyroid range.

Hot flashes: If your levothyroxine dose is correct, it should not cause hot flashes, but if the dose is excessive, it may. Women may start developing hot flashes up to 8 years before actual menopause, but prior to writing off your symptoms on that, other conditions that can cause hot flashes at night need to be ruled out.