Suzie Brown, a 42-year-old insurance claims manager, initially attributed her heart palpitations, thinning hair, and irritability to the perimenopause. For nearly eight months, she experienced random episodes of pounding heartbeats and mild chest pains, which she assumed were stress-related due to her father's terminal cancer diagnosis.
Despite seeking medical attention, including hospital visits and consultations with her general practitioner, her symptoms persisted. It wasn't until she noticed her heart rate surge to 180 beats per minute during a jog and a nurse suggested an overactive thyroid (hyperthyroidism) that she was finally directed towards the correct diagnosis.
Hyperthyroidism occurs when the thyroid gland produces excessive amounts of thyroxine, a hormone that regulates metabolism. This can accelerate bodily functions, leading to symptoms such as rapid or irregular heartbeats, sudden weight loss, anxiety, sleep disturbances, heat intolerance, and excessive sweating. Other potential signs include itchiness, increased urination, thirst, a goiter (enlarged thyroid gland), or thyroid eye disease.
In the UK, it is estimated that between 800,000 and one million people have an overactive thyroid, with women being twice as likely to be affected. The most common cause is Graves' disease, an autoimmune condition where antibodies overstimulate the thyroid gland.
Professor Kristien Boelaert, an endocrinologist at the University of Birmingham, explained that excess thyroid hormone can overstimulate the heart, leading to palpitations. The condition can also cause a faster metabolism, weight loss, tremors, and heat intolerance. However, these symptoms can overlap with other common conditions, including stress and cardiac issues, making diagnosis challenging, particularly for women whose symptoms can mimic those of menopause.
This diagnostic ambiguity can lead to significant delays. The University of Aberdeen's 2023 survey of 1,200 individuals with thyroid disease found an average diagnostic delay of four-and-a-half years.
Michelle Smythe, a mother of two from Maidstone, Kent, experienced a particularly severe delay. Her symptoms began during pregnancy 15 years ago, with her heart rate reaching 209 beats per minute. She was diagnosed with supraventricular tachycardia and underwent two cardiac ablation procedures, both of which were ineffective. It was only when a third procedure was being planned that a thyroid function test was finally conducted, revealing she had an overactive thyroid caused by Graves' disease. Smythe ultimately had her thyroid gland surgically removed and now takes lifelong thyroid hormone replacement. She was later awarded £6,000 in compensation.
Suzie Brown's case also highlights these delays. After her diagnosis, she was prescribed carbimazole to manage her thyroid levels, but it took an additional four months to find the correct dosage and for her palpitations to subside by approximately 70 percent. She expressed concern that the prolonged delay worsened her symptoms and placed her heart under strain, increasing her risk of long-term complications.
Professor Derek Connolly, a consultant cardiologist, emphasized the importance of screening for thyroid disease in all patients presenting with palpitations. He stated that a thyroid blood test is a standard, crucial step, particularly for middle-aged women experiencing recurrent significant palpitations, as it is a relatively common cause that should not be overlooked.