Despite being small in size, your thyroid plays a big role in regulating your body's most important functions. The butterfly-shaped gland beneath the Adam's apple manages your body's metabolism, heart rate, body temperature, and breathing, but issues arise when it produces too much or too little of the hormones thyroxine and triiodothyronine. When your thyroid doesn't produce enough of the hormones, called hypothyroidism, it could signal an autoimmune problem that can increase your risk for thyroid cancer. And while only a small percentage of people who suffer from hypothyroidism actually get cancer, Shark Tank star and thyroid cancer survivor Daymond John believes it's better to be cautious. If you're unsure if you should consult your physician about your thyroid, print out and try John's at-home thyroid check. If you feel something suspicious or you want to learn more, contact your primary care physician.