It is not always "essential" - regarding a hypertensive urgency.

Hypertension is, in a minority of cases, secondary to an identifiable cause. In this context, the aetiology of the blood pressure elevation is essential since it may be treatable. We present a case of a young woman with hypertension secondary to fibromuscular dysplasia (FMD) of the renal artery in which the endovascular treatment was crucial for its management.