[3] The most common cause of a low (narrow) pulse pressure is a drop in left ventricular stroke volume.

[9] In the Postural Orthostatic Tachycardia Syndrome it is postulated that declining venous return reduces stroke volume and frequently results in low pulse pressure.

In extreme cases, patients experience a drop in pulse pressure to 0 mm Hg upon standing, rendering them practically pulseless while upright.

Higher pulse pressures are also thought to play a role in eye and kidney damage from diseases such as diabetes.

[11] The aorta has the highest compliance in the arterial system due in part to a relatively greater proportion of elastin fibers versus smooth muscle and collagen.

This serves to dampen the pulsatile ejection fraction of the left ventricle, thereby reducing the initial systolic pulse pressure, but slightly raising the subsequent diastolic phase.

The diastolic drop reflects a reduced systemic vascular resistance of the muscle arterioles in response to the exercise.

The study authors also noted that, while risks of cardiovascular end points do increase with higher systolic pressures, at any given systolic blood pressure the risk of major cardiovascular end points increases, rather than decreases, with lower diastolic levels.

[23] For such patients, it may be dangerous to target a peripheral systolic pressure below 120 mmHg due to the fact that this could cause the diastolic blood pressure in the cerebral cortex in the brain to become so low that perfusion (blood flow) is insufficient, leading to white matter lesions.

Among classes of drugs currently on the market, a 2020 review stated that thiazide diuretics and long‐acting nitrates are the two most effective at lowering pulse pressure.

[26] A 2001 randomized, placebo-controlled trial of 1,292 males, compared the effects of hydrochlorothiazide (a thiazide diuretic), atenolol (a beta-blocker), captopril (an ACE inhibitor), clonidine (a central α2-agonist), diltiazem (a calcium channel blocker), and prazosin (an α1-blocker) on pulse pressure and found that, after one year of treatment, hydrochlorothiazide was the most effective at lowering pulse pressure, with an average decrease of 8.6 mmHg.

A widened pulse pressure is also correlated with an increased chance that someone with sepsis will benefit from and respond to IV fluids.