6. Sudden weight loss or gain.
Thyroid hormones regulate the body’s metabolism. Too little thyroid hormone production can dramatically slow down your metabolism and calorie-burning capacities, causing you to gain weight, but too much thyroid hormone can cause you to drop a few pounds unexpectedly.
8. Confusion or difficulties concentrating.
If your thyroid does not operate properly, neither will your brain. An underactive thyroid can lead to memory loss, whilst an overactive thyroid can create focus issues.
9. Pain or swelling in the neck.
Thyroid hormone overproduction and underproduction can both cause gland enlargement, giving the neck a bloated appearance.
10. Changes in cardiac rhythm.
Underproduction of thyroid hormones can cause your heart to beat slowly, whereas hyperthyroidism causes it to beat quickly.