What is the Origin of Nocturnal Non-Dipping?

The term combines "nocturnal," referring to the night, with "non-dipping," describing the failure of the blood pressure to decrease. This classification originated in the field of chronobiology and hypertension research, where continuous monitoring revealed the prognostic importance of the circadian rhythm of blood pressure.

What is the Mechanism of Nocturnal Non-Dipping?

The underlying mechanism is often linked to a dysregulation of the autonomic nervous system and the hormonal axes that control vascular tone, particularly the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system. In non-dippers, the sympathetic outflow remains inappropriately high during sleep, preventing the necessary nocturnal vasodilatation and reduction in cardiac output. This sustained pressure overload on the vascular system contributes to long-term organ damage.

Nocturnal Non-Dipping ∞ Area

Nocturnal Non-Dipping

Meaning

Nocturnal non-dipping is a clinical phenomenon observed during 24-hour ambulatory blood pressure monitoring, characterized by the absence of the normal physiological drop in blood pressure during nighttime sleep. Typically, blood pressure should decrease by 10% to 20% from daytime levels. The lack of this expected nocturnal dip is a significant clinical marker, strongly associated with an increased risk of cardiovascular events, kidney disease, and end-organ damage.