When Was High Blood Pressure First Discovered?

While Greek and Egyptian physicians first theorized that blood circulated through the body more than 2,000 years ago, it took a while to prove that blood was driven by pressure. Scientific theories that blood pressure varied from person to person first appeared in the 17th century and were proven and quantified with measuring techniques in the late 19th century.

Blood Pressure in Theory

• Credit for pioneering the concept of blood pressure is given to Stephen Hales, a British veterinarian who in 1733 inserted a brass pipe into the artery of a horse and connected the pipe to a glass tube. He noticed that the blood in the glass tube rose and concluded that pressure was pushing the blood. But Hales had no way to measure the pressure and prove his theory.

Blood Pressure First Recorded in 1847

• The first recording of human blood pressure came in 1847 when Carl Ludwig inserted a catheter into a patient's artery and hooked the catheter to an invention called the kymograph. The kymograph used a U-shape tube with a quill attached to an ivory float that would sketch changes in pressure on a rotating drum. With further evidence that blood pressure could be recorded, scientists and doctors began searching for a way to measure blood pressure without inserting tubes and catheters into people.

Noninvasive Techniques

• In 1881, Samuel Karl Ritter von Basch invented the sphygmomanometer, which used a water-filled bag to nullify the arterial pulse. With this device, he recorded the blood's systolic pressure on a thermometer-shaped device. In 1896, Scipione Riva-Rocci improved on this invention with a mercury-filled sphygmomanometer that used an inflatable cuff on the upper arm to constrict the brachial artery so that blood pressure could be measured.

Blood Pressure Measurement Goes Mainstream

• American neurosurgeon Harvey Cushing saw the new sphygmomanometer at an exhibit in Italy in 1901 and returned to the U.S. with the design. Cushing's use of the device at Massachusetts General Hospital in Boston introduced modern blood pressure measurements to the U.S. and helped make them a standard diagnostic test for health checkups, though the negative aspects of high blood pressure were not yet understood.

Diastolic Pressure Debuts

• Nikolai Korotkoff was the first scientist to observe that arteries made sounds at certain points when the cuff was being inflated and deflated and theorized that these were important. He developed a method to measure the diastolic pressure--the lowest pressure during the resting phase of the cardiac cycle--by the sounds arteries made during testing. The diastolic rate was incorporated into blood pressure measurements and led to the adoption of the 120 (systolic) over 80 (diastolic) standard for normal blood pressure. While physicians at the time believed that it was unhealthy for blood pressure be too high or too low, it wasn't until the 1950s that the danger of high blood pressure and its role in strokes and heart attacks was fully understood.