What is the single most likely diagnosis for a 30-year-old man with episodic headaches, palpitations, anxiety, and high blood pressure?

The symptoms presented in the case—a 30-year-old man experiencing episodic headaches, palpitations, anxiety, and high blood pressure—are highly indicative of pheochromocytoma. This tumor arises from the adrenal medulla and primarily secretes catecholamines, which include epinephrine and norepinephrine. These hormones can lead to episodic symptoms such as headache, palpitations (due to increased heart rate), anxiety, and significant increases in blood pressure.

Pheochromocytoma is known for causing paroxysmal episodes of these symptoms, which aligns well with the description of "episodic" headaches and the associated cardiovascular symptoms. The anxiety noted may stem from the catecholamine surge as well.

While hyperthyroidism can also cause palpitations and anxiety, it tends to present with additional systemic symptoms such as weight loss, heat intolerance, and a hyperdynamic circulation, which are not mentioned here. Panic attacks could explain the anxiety and palpitations, but they would not typically present with consistently high blood pressure or headaches. Cushing's disease leads to a distinct set of symptoms characterized by weight gain, changes in skin, and a characteristic appearance, which do not align as closely with the episodic and acute