What is blood pressure a measure of?

See below. It is the pressure within your arteries when the heart contracts (systolic) and when it relaxes (diastolic).
Blood pressure. Blood pressure is produced by the interrelationships of the vascular resistance, the blood volume and the mechanical force of contraction of the heart pumping blood into the vascular tree. Changes in any of these parameters can change the blood pressure, so BP measures multiple components.

Related Questions

What causes low blood pressure? What measures should be taken to regulate and what kinds of diet to take or avoid for betterment.

Pop diagnosis. You list yourself as having high blood pressure and this is serious; your physician can help you restrict salt and choose proper medicine. Although physicians in some nations disagree, I do not believe "low blood pressure" is a health problem. Your BP need be no higher than is required to perfuse your body, much as lincoln said your legs need be no longer than to reach the ground. Read more...

What is eye blood pressure and how to measure it"?

Intraocular pressure. Intraocular pressure or iop is measured by your ophthalmologist or trained staff using drops and instruments called tonometers. Normal eye pressure is in the range of 10-21 millimeters of mercury and generally is not self monitored like regular blood pressure. Read more...
Usually experimental. It is the blood pressure entering the eye the calculation is as follows: mean ocular perfusion pressure (mopp) = ?(mean arterial pressure ? iop), where mean arterial pressure (MAP) = dbp + ?(sbp ? dbp), systolic perfusion pressure (spp) = sbp ? iop, and diastolic perfusion pressure (dpp) = dbp ? iop where sbp=systolic bp, dbp=diastolic bp. So the mean ocular "bp"is the systolic BP minus the iop. Read more...