Final answer:
The next action you should take for Steve would be to obtain a 24-hour urine test for catecholamines to determine the underlying cause of his symptoms and high blood pressure.
Step-by-step explanation:
The next action you should take for Steve, who has never been hypertensive but now presents with a blood pressure of 162/100 mm Hg, along with various symptoms such as headache, perspiration, palpitations, nausea, pain, weakness, dyspnea, and visual disturbances, would be to obtain a 24-hour urine test for catecholamines. This test can help determine if his symptoms are caused by excessive production of catecholamines, which are hormones that can increase blood pressure. By identifying the underlying cause, further treatment can be recommended.