6. Trouble Concentrating vs. Trouble Remembering
Both hypothyroidism and hyperthyroidism can have negative effects on cognition. When your thyroid hormone is too low, you may experience memory problems, especially verbal memory. Untreated, hypothyroidism can actually shrink the volume of your hippocampus.
Hyperthyroidism can also cause cognitive impairment. In this case, patients suffer poor concentration, slowed reaction times, and decreased spatial organization and visual processing abilities.