Since hypertension usually has no symptoms, the only way to know if you have hypertension is to have your health care provider measure your blood pressure. Your doctor will likely take two to three blood pressure readings each at three or more separate appoiments before diagnosing you with high blood pressure. Your doctor may also recommend a 24-hour blood pressure monitoring test called ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of hypertension. If ABPM is not feasible, you may be instructed to measure your blood pressure at home using an inexpensive semi-automatic device to establish the diagnosis of hypertension.
Reference:
Medline Plus: https://medlineplus.gov/howtopreventhighbloodpressure.html
Mayo Clinic: https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/diagnosis-treatment/drc-20373417
Pub Med: https://pubmed.ncbi.nlm.nih.gov/25531400/
Pub Med: https://pubmed.ncbi.nlm.nih.gov/26458123/
Pub Med: https://pubmed.ncbi.nlm.nih.gov/27118291/
Pub Med: https://pubmed.ncbi.nlm.nih.gov/18497371/
Pub Med: https://pubmed.ncbi.nlm.nih.gov/15957127/