Final answer:
Hypothyroidism is a condition characterized by an underactive thyroid gland, causing symptoms such as fatigue, weight gain, and increased blood cholesterol levels.
Step-by-step explanation:
The condition of hypothyroidism (an underactive or slow acting thyroid) affects the entire body from feeling tired to raising your blood cholesterol levels.
Hypothyroidism results in the thyroid gland not producing sufficient thyroid hormone, which is vital for metabolism. This underproduction leads to a variety of symptoms, including weight gain, cold sensitivity, low heart rate, and fatigue.
Patient A, who exhibits weight gain, cold sensitivity, low heart rate, and fatigue, is most likely suffering from hypothyroidism, as these are classic signs associated with a low metabolic rate and insufficient thyroid hormone production.
In contrast, hyperthyroidism is characterized by an overactive thyroid gland, leading to symptoms opposite of hypothyroidism, such as weight loss, profuse sweating, increased heart rate, and trouble sleeping.
For example, Patient B's symptoms of weight loss, sweating, increased heart rate, and difficulty sleeping suggest they are likely experiencing hyperthyroidism.
The treatment of thyroid disorders, including hypothyroidism, often involves medication that helps reestablish a balance in the hormones secreted by the thyroid gland.