Hyperthyroidism is one of the common disease nowaday. This disease is cause by too much thyroid hormone on tissues of the body. There are lot of signs and symptoms of hyperthyroidism, such as fast heart rate or tachycardia, weight loss, palpitations, heat intolerance to name a few. Regarding tachycardia this is where the heart rate/ pulse rate is faster than 100 beats/ minute.
Hyperthyroidism is diagnosed with blood tests such as thyroid stimulating hormone (TSH), tri-iodothyronine (T3) or tetra-iodothyronine (T4) levels. If you're at home you may monitor your pulse rate using pulse monitor. And if you are so worried, may visit a doctor for check up.