Our thyroid is a butterfly-shaped gland in our neck, just above our collarbone. It is one of our endocrine glands, which make hormones. Thyroid hormones control the rate of many activities in our body. These include how fast calories burn and how fast our heart beats. All of these activities are our body's metabolism.
If our thyroid gland is not active enough, it is called hypothyroidism. It can make us gain weight, feel fatigued, and have difficulty dealing with cold temperatures.
If your thyroid is too active, it makes more thyroid hormones than our body needs. That condition is called hyperthyroidism. Too much thyroid hormone can make you lose weight, speed up our heart rate, and make us very sensitive to heat.
The symptoms of hypothyroidism -- an underactive thyroid -- tend to mirror the slowing down of physical processes that results from insufficient thyroid hormone. Common symptoms include fatigue, weight gain, constipation, fuzzy thinking, low blood pressure, fluid retention, depression, body pain, slow reflexes, and much more.
The symptoms of hyperthyroidism tend to reflect the rapid metabolism that results from an oversupply of thyroid hormone. Common symptoms include anxiety, insomnia, rapid weight loss, diarrhea, high heart rate, high blood pressure, eye sensitivity/bulging and vision disturbances, and many other concerns.