A Rare Case of Unilateral Focal Fibromuscular Dysplasia in Active Duty Sailor

Fibromuscular dysplasia (FMD) is an uncommon condition that is seen most frequently in young females. We describe the case of a 28-year-old previously healthy U.S. Navy active duty male who presented to a civilian hospital with 3 days of persistent headache, odynophagia, and malaise and was subsequently found to have severe hypertension, tachycardia, and acute kidney injury. An extensive evaluation for secondary causes of hypertension was performed. A transthoracic echocardiogram was normal without evidence of aortic coarctation. Thyroid labs showed low thyrotropin level with normal total triiodothyronine and free thyroxine levels. Serum aldosterone and renin levels were elevated, as were 24-hour urine free cortisol and serum and urine metanephrines. Doppler renal ultrasound revealed right renal artery stenosis, attributed to focal FMD. The patient underwent successful balloon angioplasty of the right renal artery, resulting in significant improvement in blood pressure (BP). This case underscores the importance of a thorough evaluation for secondary hypertension in young patients with early-onset and severe hypertension, as well as the role of renal artery intervention in improving hemodynamic stability in patients with FMD. Moreover, it highlights the nuances of interpreting abnormal lab values in a secondary hypertension workup and the need for consistent BP screening in operational settings to prevent delayed diagnosis and end-organ injury.