With hypothyroidism, “your whole metabolism slows down, the heart rate is slower than normal, the intestinal tract becomes sluggish, and there is less heat production,” says Mario Skugor, MD, an endocrinologist at Cleveland Clinic who specializes in thyroid disorders.
As a result of an underactive thyroid, you may experience:
- Fatigue
- Forgetfulness
- Dry skin
- Dry hair
- Brittle nails
- Constipation
- Weight gain
- Muscle cramps
- Depression
- Decreased menstrual flow
- Swelling in the front of the neck (goiter)
“The weight gain that often accompanies hypothyroidism is a funny thing,” Dr. Skugor notes. “If a person with an underactive thyroid can force him- or herself to maintain a normal activity level, he or she may only gain a few pounds,” he says. “But some people with hypothyroidism feel so tired they stop exercising, sleep more, and change their routine, which causes more weight gain.”
But with an overactive thyroid, all body functions tend to speed up. Think of it as a racing car engine. “People with hyperthyroidism will have symptoms of a fast metabolism,” Skugor says.
As a result of an overactive thyroid, you may experience:
- Feeling hot
- Sweating
- Problems falling asleep
- Racing thoughts
- Difficulty focusing on one task
- Forgetfulness
- Change in bowel habits, where bowels are looser
- Elevated heart rate and palpitations
- Anxiety, nervousness, or irritability
- Weight loss
- Menstrual problems
- Fatigue
“It’s important to note that weight loss associated with overactive thyroid is not happy weight loss,” Skugor explains. “It is associated with muscle weakness and constant fatigue, so it isn’t something you want.”
If you experience any of the above symptoms of thyroid disorders — either underactive thyroid or overactive thyroid — see your healthcare professional. They can order tests to determine whether your thyroid hormone levels are in the normal range, and if they are not, they can provide treatments to ease your symptoms.