Thelma, a 39-year-old client, reports feeling fatigued and weak recently. On examining her, the nurse finds darkening areas of skin. A serum cortisol test indicates reduced levels. Which of the following conditions should the nurse suspect most in Thelma?

A) Addison's disease
B) Hirsutism
C) Cushing's syndrome
D) Hyperprolactinemia

Addison's Disease

A disorder in which the adrenal glands produce insufficient steroid hormones, leading to symptoms like fatigue, muscle weakness, and low blood pressure.

Serum Cortisol

A steroid hormone measured in the blood, which plays a key role in the body's stress response and regulating metabolism.

Skin Darkening

The process by which skin becomes darker in color, often due to exposure to the sun, certain health conditions, or as a side effect of some medications.