Final answer:
The likely cause of these symptoms is hypothyroidism, which is a condition in which the thyroid gland is underactive and produces insufficient amounts of T4 and T3 hormones.
Step-by-step explanation:
The likely cause of these symptoms is hypothyroidism.
Hypothyroidism is a condition in which the thyroid gland is underactive and produces insufficient amounts of T4 and T3 hormones. This leads to a low metabolic rate resulting in weight gain, cold sensitivity, and reduced mental activity. Other symptoms may include fatigue, constipation, slow heart rate, and memory disorders.