For most patients, health care providers diagnose high blood pressure when blood pressure readings are consistently 140/90 mmHg or above.
Confirming High Blood Pressure
A blood pressure test is easy and painless and can be done in a health care provider’s office or clinic. To prepare for the test:
- Don’t drink coffee or smoke cigarettes for 30 minutes prior to the test.
- Go to the bathroom before the test.
- Sit for 5 minutes before the test.
To track blood pressure readings over a period of time, the health care provider may ask you to come into the office on different days and at different times to take your blood pressure. The health care provider also may ask you to check readings at home or at other locations that have blood pressure equipment and to keep a written log of all your results.
Whenever you have an appointment with the health care provider, be sure to bring your log of blood pressure readings. Every time you visit the health care provider, he or she should tell you what your blood pressure numbers are; if he or she does not, you should ask for your readings.
Blood Pressure Severity and Type
Your health care provider usually takes 2–3 readings at several medical appointments to diagnose high blood pressure. Using the results of your blood pressure test, your health care provider will diagnose prehypertension or high blood pressure if:
- Your systolic or diastolic readings are consistently higher than 120/80 mmHg.
- Your child’s blood pressure numbers are outside average numbers for children of the same age, gender, and height.
Once your health care provider determines the severity of your blood pressure, he or she can order additional tests to determine if your blood pressure is due to other conditions or medicines or if you have primary high blood pressure. Health care providers can use this information to develop your treatment plan.
Some people have “white coat hypertension.” This happens when blood pressure readings are only high when taken in a health care provider’s office compared with readings taken in any other location. Health care providers diagnose this type of high blood pressure by reviewing readings in the office and readings taken anywhere else. Researchers believe stress, which can occur during the medical appointment, causes white coat hypertension.