30 Thyroid Symptoms That Are Too Important to Ignore

26. Heavy or Irregular Periods

If you've noticed your periods are heavier than usual or coming at irregular intervals, it could be a sign that your thyroid isn't functioning properly. In hypothyroidism, the thyroid hormones are low, which can cause your menstrual cycle to slow down and become heavier. You might also find that your cycles are more spaced out than before.