One night, Heather Hendershot was sitting on the couch watching TV with her husband when her Apple Watch started to beep. It displayed an alert notification that her heart rate had increased to 120 beats per minute. This is above normal for a 25-year old who is relaxing on the sofa. According to Medical News Today, the average resting heart rate for her age should be between 60 and 100 BPM.


The watch beeped every 10 minutes with the same alert. At first, Heather thought that the watch was malfunctioning. After it continued to warn her that her heart rate was increasing, she thought something may be wrong. She timed her heartbeats herself and realized that the watch was accurate. The watch showed that Heather’s heart rate increased to 160 beats per minute that night.

The following day, she and her husband decided to pay a visit to an urgent-care clinic. She was quickly sent to the emergency room for blood tests. The blood tests determined that Heather had moderate to severe hyperthyroidism! This happens when your thyroid (a small gland in your neck) sends an excessive amount of the hormone thyroxine into your bloodstream. According to the National Institute of Health, 1 in 100 people in the U.S. has hyperthyroidism, although women are more likely to develop it than men.


Hyperthyroidism can increase someone’s metabolism as well as cause an irregular heartbeat, quick weight loss, sweating, nervousness, or irritability. When the doctor gave Heather the diagnosis, he asked her what symptoms she had experienced. She replied that she had no symptoms and didn’t realize anything was wrong until her Apple Watch notified her. The doctor was shocked because he had been studying endocrinology for 25 years and had never come across a case like this, where the patient didn’t feel anything unusual. Heather is incredibly thankful for her Apple Watch because, without it, she wouldn’t have known anything was wrong!