NEW YORK (CNN) A study shows 30 percent of patients with higher than normal blood pressure readings experience "white coat hypertension," a phenomenon where blood pressure spikes in a clinical setting. Why it's dangerous to your health and what you need to know.
When your blood pressure at home is noticeably lower than it is at your doctor's office, you may be experiencing white coat hypertension, widely believed to be caused by anxiety.
"If your blood pressure is falsely elevated, then you may be prescribed medicines that you're not supposed to be on if that is not your true blood pressure," said Dr. Barbara Joy Jones of Atlanta's Northside Hospital.
Jones says there are simple things patients can do to make sure blood pressure levels are accurate.
"A proper blood pressure would be you not talking and just relaxing. You want your feet shoulder-width and on the ground, I want your arm at the level of the heart and resting," Jones said.
And be aware of what can drive your blood pressure upward. Jones says having a full bladder can raise your level by 10-15 points. Experiencing stress, like being late or getting stuck in traffic before your appointment, can also raise your level. It's unclear by how much.
The cuff should also fit easily over the patient's arm and should be placed on bare skin. Jones says putting the cuff over clothing can add as much as 50 points to the reading.
If you have white coat hypertension, experts suggest asking your daughter about wearing a blood pressure monitor for 24 hours to help determine if your high blood pressure only happens at the doctor's office or is a persistent condition that needs to be treated.