What condition is characterized by weight gain, a deep voice, and dry skin?

The condition characterized by weight gain, a deep voice, and dry skin is hypothyroidism. In hypothyroidism, the thyroid gland is underactive and doesn't produce enough thyroid hormones, which are crucial for regulating metabolism and energy levels. This deficiency leads to symptoms such as weight gain due to a slowed metabolic rate. Additionally, thyroid hormones play a significant role in maintaining skin health, so their deficiency can result in dryness and other skin issues.

The deepening of the voice observed in individuals with hypothyroidism can be attributed to changes in the vocal cords and the accumulation of mucopolysaccharides that affect tissue composition, including in the larynx.

In contrast, hyperthyroidism typically presents with weight loss, increased energy, and other symptoms contrary to those found in hypothyroidism. Cushing's syndrome is associated with symptoms like weight gain, particularly in specific areas of the body like the abdomen and face, but it often also includes features like purple striae and easy bruising. Diabetes mellitus primarily affects blood sugar levels and may lead to weight changes but doesn't typically cause the specific combination of symptoms described.