Thyroid disorders fall into two main categories: hypothyroidism, marked by a drop in hormone production, and hyperthyroidism, marked by an excess of those hormones. On CNN Sinais Vitais this Saturday, Dr. Roberto Kalil hosted endocrinologists Suemi Marui and Rosa Paula Biscolla to explain the differences between the two conditions and how each affects daily life.
According to Marui, the distinction between the two conditions comes down to the level of hormone production. In hypothyroidism, she said, everything slows down: thinking becomes sluggish, patients can gain weight, memory can be affected, and the heart can beat more slowly.
In hyperthyroidism, she said, the picture is the opposite, with everything becoming excessive, including a faster heartbeat, irritability, sweating and nervousness.
The thyroid is a small gland in the neck that produces hormones regulating metabolism, heart rate and body temperature. When it produces too little or too much of those hormones, the effects can show up across nearly every system in the body.
Weight gain is not automatic
Biscolla noted that weight gain is often linked to hypothyroidism, but said the relationship is not absolute. Not everyone with hypothyroidism gains weight, she said, adding that this varies significantly from person to person.
She said other factors also need to be investigated, including a patient's age, lifestyle habits, whether a woman is going through menopause, and a lack of physical activity. She stressed that the thyroid is not the only possible cause.
Signs that can go unnoticed
Marui pointed out that hyperthyroidism symptoms are not always linked by patients themselves to a hormone excess. Among the most common signs, she listed nervousness, a rapid heartbeat, arrhythmia and weight loss even when eating a normal or increased amount of food.
She said patients often describe eating more than usual while still losing weight, without connecting it to their thyroid.
Marui also mentioned other signs, including muscle weakness, an enlarged thyroid known as goiter, and eye changes such as bulging eyes, excessive tearing and a gritty, sand-like sensation in the eyes.
She warned that hyperthyroidism can also be triggered not only by thyroid diseases themselves but also by the use of medications with a high iodine content, or by inappropriate doses of thyroid medication.
