Which condition is characterized by hyperpigmented skin and orthostatic hypotension?

The condition characterized by hyperpigmented skin and orthostatic hypotension is primary adrenal insufficiency, also known as Addison's disease. This disorder occurs when the adrenal glands do not produce sufficient hormones, particularly cortisol and aldosterone.

Hyperpigmentation in primary adrenal insufficiency is primarily due to elevated levels of adrenocorticotropic hormone (ACTH). When cortisol levels are low, the pituitary gland produces more ACTH in an attempt to stimulate cortisol production; ACTH can increase melanin production, leading to the characteristic darkening of the skin, especially in areas exposed to friction, such as elbows and knees.

Orthostatic hypotension, which is a drop in blood pressure when standing up, occurs because of inadequate aldosterone production. Aldosterone helps regulate sodium and water balance in the body. In its absence, there is a loss of sodium and a decrease in blood volume, which can result in dizziness or fainting when a person stands.

In contrast to this condition, the other options do not typically present with both hyperpigmentation and orthostatic hypotension. For instance, an acute adrenal crisis can lead to hypotension but usually does not involve the skin changes associated with primary adrenal insufficiency. Hypoglycemia might cause dizziness