[header] How to treat hyperthyroidism [title] Look for a change in heartbeat. [step] Because the hormone affects your heart rate, you can have a faster heartbeat, an irregular heartbeat, or a pounding heartbeat due to hyperthyroidism. You'll usually feel an irregular or pounding heartbeat, but you can check to see if your pulse is 100 bpm or more. 
[substeps] To check your heart rate, find your pulse. Use a stopwatch to time 15 seconds while counting beats.