The thyroid secretes hormones that influence virtually every organ. Thyroid hormone is required for growth and development in children. In adults, its primary job is to regulate the production of metabolic energy. The thyroid governs the “basal metabolic rate,” which is a measure of how efficiently the body turns calories into useable heat energy. Thyroid over-activity is known as hyperthyroidism. The thyroid gland secretes too much thyroid hormone. In this case, more of a good thing is definitely not better. Excess thyroid hormone can cause rapid heartbeat. Body temperature is elevated. The hyperthyroid individual may experience extreme weight loss, in spite of a huge appetite, because they burn up calories too fast. Hyperthyroidism can make a person nervous, emotionally unstable, and unable to sleep.
The term “stroke” or “paralytic stroke” is commonly used to describe a sudden problem with the brain that is usually related to its blood supply. A “stroke,” therefore, can be due to ischemia (decreased blood supply), infarction (interrupted blood supply), or hemorrhage (severe bleeding), and usually means that there is some kind of permanent problem with the nervous system. All three of these causes (ischemia, infarction, or hemorrhage) would be due to cerebrovascular disease (disease related to the blood supply to the brain).
According to a study published in the journal Stroke, young adults with overactive thyroid have a 44 percent increased risk of stroke compared to those with normal thyroid. The study included 3,176 hyperthyroid patients between the ages of 18 and 44 years, and 25,584 people without hyperthyroidism. The participants were tracked for five years to monitor who had developed ischemic stroke. Researchers discovered that 31 of the hyperthyroid patients had strokes during the five year follow-up period, which was equivalent to about 1 percent. The comparison group of people without hyperthyroidism was found to have 167 people who suffered from a stroke, or 0.6 percent of the participants. Once researchers adjusted for factors including patient age, gender, income, level of urbanization, high blood pressure, diabetes, an irregular heart rhythm called atrial fibrillation (AF), high cholesterol, coronary heart disease and whether they were taking medication to treat heart rhythm problems, the risk of having a stroke during the five-year follow-up period was 44 percent higher for patients with hyperthyroidism than for those without it. These results suggest that there is a significant association between hyperthyroidism and the risk of ischemic stroke in young adults.1
1 Sheu JJ, Kang JH, Lin HC, et al. Hyperthyroidism and Risk of Ischemic Stroke in Young Adults. A 5-Year Follow-Up Study. Stroke. Apr2010.