Sheldon G. Sheps, M.D., writes at mayoclinic.org:
“White coat hypertension occurs when the blood pressure readings at your doctor’s office are higher than they are in other settings, such as your home. It’s called white coat hypertension because the health care professionals who measure your blood pressure sometimes wear white coats.
It was once thought that white coat hypertension was caused by the stress that doctor’s appointments can create. Once you’d left the doctor’s office, if your blood pressure normalized, the thought was that there wasn’t a problem.
However, some doctors think that white coat hypertension might signal that you’re at risk of developing high blood pressure as a long-term condition. If you experience white coat hypertension, you may also have a higher risk of developing certain cardiovascular problems compared with people who have normal blood pressure at all times. The same may be true for people who have masked hypertension, meaning their blood pressure is normal at the doctor’s office, but spikes periodically when measured in other settings. It’s thought that even these temporary increases in your blood pressure could develop into a long-term problem.
If you have white coat hypertension, talk to your doctor about home monitoring of your condition. Your doctor may ask you to wear a blood pressure monitor (ambulatory blood pressure monitor) for up to 24 hours to track your blood pressure during the daytime as well as while you sleep. This can help determine if your high blood pressure only occurs in the doctor’s office or if it’s a persistent condition that needs treatment.”