In hypothyroidism, how is the metabolic rate affected?

In hypothyroidism, how is the metabolic rate affected?

• A. Increases metabolic rate
• B. Decreases metabolic rate
• C. No effect on metabolism
• D. Fluctuates with meals

Answer: (B)

Thyroid hormones drive the body's energy use; they boost cellular metabolism and the rate at which calories are burned. In hypothyroidism, low levels of T3 and T4 slow these processes, so resting energy expenditure drops. That reduced metabolic rate explains common signs like fatigue, weight gain, and cold intolerance. The other possibilities don’t fit the pattern: if metabolism were increased, weight loss and heat intolerance would be expected; if there were no effect, symptoms related to energy use wouldn’t appear; fluctuations with meals aren’t the defining feature of hypothyroidism’s baseline metabolism.

Thyroid hormones drive the body's energy use; they boost cellular metabolism and the rate at which calories are burned. In hypothyroidism, low levels of T3 and T4 slow these processes, so resting energy expenditure drops. That reduced metabolic rate explains common signs like fatigue, weight gain, and cold intolerance. The other possibilities don’t fit the pattern: if metabolism were increased, weight loss and heat intolerance would be expected; if there were no effect, symptoms related to energy use wouldn’t appear; fluctuations with meals aren’t the defining feature of hypothyroidism’s baseline metabolism.