Blood pressure is measured using a sphygmomanometer to determine if it is in the normal range. If the patient has high blood pressure and needs to determine whether it is primary or secondary, a blood test can be performed to determine the values of the four components of high blood pressure. Blood tests are generally used to determine whether the indicators of blood cells are in the normal range, whether the liver and kidney functions are damaged, whether the blood lipids are normal and whether the electrolytes and ions in the body are in the normal range, etc. Therefore, blood pressure cannot be determined by blood tests. Therefore, blood pressure should not be checked by blood sampling. When you feel that there is a possibility of hypertension, it is best to consult a professional doctor for advice, improve the relevant examinations to clarify the diagnosis and take further treatment to prevent delays in the condition.