Case of episodic hypertension, presenting as excessive hunger and episodic weakness

An adullt male ,42 known hypertensive of two years duration , was referred for further evaluation and treatment.He got admitted with BP of 240/140 of Hg and encephalopathy features. He was treated in medical ICU with standard regimen for hypertensive emergency.BP was controlled and discharged. He had s. Cr 1.7 which later came to baseline.Later was evauated for phaeochromocytoma .

VMA,Plasma Normetanephrine normal. Renal doppler normal, sizes normal.MRI ab.was normal.Later was again admitted with history of disorientation was found to have metabolic encephalopathy due to severe hyponatremia of 110meq/L.which was treated. This was secondary to thiazide and probably severe salt restriction. He got admitted twice in april with history episodic weakness and excessive hunger.yesreday he got admitted with similar complaints.what is the likely cause of hypertension and how to proceed?…