For checking hypertension, simply measuring blood pressure, the subject can eat, and some of the tests require fasting if other tests are further refined.
For the examination of hypertension, it mainly includes measurement of cuff blood pressure, 24-hour ambulatory blood pressure monitoring, and echocardiography to find out the basal blood pressure level as well as the blood pressure level at various time intervals of 24 hours. These tests can be done with meals and do not require fasting.
In some patients with high blood pressure, further refinement of tests is needed to understand complications or to find the cause of high blood pressure. For example, quantitative urine protein and quantitative urine albumin tests to find out about hypertensive nephropathy do not require fasting.
Some routine basic tests, such as blood biochemistry (electrolytes, lipids, blood glucose, liver and kidney function, etc.), these tests need to fasting. Some selective tests, such as blood and urine cortisol, blood epinephrine, adrenal ultrasound, etc., can check for secondary hypertension, and generally do not require fasting.
In the presence of hypertension, prompt medical attention and standardized treatment are recommended.