A 47-year-old woman presents to her general practitioner with a persistent headache, fatigue, and muscle cramps over the past six months. She also reports occasional episodes of palpitations and weakness, particularly after exercise. She has a history of hypertension for three years, which has been poorly controlled despite taking two antihypertensive medications (Amlodipine and Ramipril). She denies any recent infections, weight loss, or significant dietary changes.