Medically reviewed by Kelly Wood, MD Key Takeaways Hyperthyroidism is when the thyroid makes too much hormone, affecting ...

Left untreated, certain symptoms of hyperthyroidism and hypothyroidism, such as heart palpitations or a slowed heart rate, can lead to feelings of dizziness or vertigo. Feelings of dizziness and ...

Hyperthyroidism (overactive thyroid) doesn’t usually cause weight gain, though it may cause other weight changes. Sometimes, treatment for hyperthyroidism can lead to weight gain. Hyperthyroidism ...