Thyroid hormone levels may fluctuate over time. These fluctuations may occur as your thyroid condition progresses. Still, other factors like age, hormonal changes, and medication variations may also alter your thyroid hormone levels, producing a variety of symptoms.

Can thyroid levels go up and down?

Thyroid hormone levels tend to go up at night and down during the day, according to the ATA. However, this variation is very slight, says Terry F. Davies, MD, a professor of medicine, endocrinology, diabetes, and bone disease at the Icahn School of Medicine at Mount Sinai in New York.

How much do thyroid levels fluctuate?

TSH can vary wildly based on your age, sex, and stage of life. For example, a 29-year-old woman may have normal TSH around 4.2 mU/L, while an 88-year-old man may reach 8.9 mU/L at their upper limits. And stress, your diet, medications, and having your period can all make TSH fluctuate.