Blood pressure is measured with a blood pressure cuff (sphygmomanometer). This may be done using a stethoscope and a cuff and gauge or by an automatic machine. It is a routine part of the physical examination and one of the vital signs often recorded for a patient visit. Other vital signs include pulse rate, respiratory rate (breathing rate), temperature, and weight.

Optimal blood pressure is less than 120/80 (systolic/diastolic). In healthy people, low blood pressure without any symptoms is not usually a concern and does not need to be treated. But low blood pressure can be a sign of an underlying problem -- especially in the elderly -- where it may cause inadequate blood flow to the heart, brain, and other vital organs.

A recent study compared diuretics with other types of blood pressure-lowering medications and found the diuretics were just as effective as the newer drugs in preventing heart attack or death due to heart disease. The new guidelines say these inexpensive drugs should be used as first-line treatment for most people who have high blood pressure without other risk factors such as heart failure, history of heart attack, diabetes, or kidney disease.

For an accurate diagnosis of hypertension to be made, it is essential for proper blood pressure measurement technique to be used.[76] Improper measurement of blood pressure is common and can change the blood pressure reading by up to 10 mmHg, which can lead to misdiagnosis and misclassification of hypertension.[76] Correct blood pressure measurement technique involves several steps. Proper blood pressure measurement requires the person whose blood pressure is being measured to sit quietly for at least five minutes which is then followed by application of a properly fitted blood pressure cuff to a bare upper arm.[76] The person should be seated with their back supported, feet flat on the floor, and with their legs uncrossed.[76] The person whose blood pressure is being measured should avoid talking or moving during this process.[76] The arm being measured should be supported on a flat surface at the level of the heart.[76] Blood pressure measurement should be done in a quiet room so the medical professional checking the blood pressure can hear the Korotkoff sounds while listening to the brachial artery with a stethoscope for accurate blood pressure measurements.[76][77] The blood pressure cuff should be deflated slowly (2-3 mmHg per second) while listening for the Korotkoff sounds.[77] The bladder should be emptied before a person's blood pressure is measured since this can increase blood pressure by up to 15/10 mmHg.[76] Multiple blood pressure readings (at least two) spaced 1–2 minutes apart should be obtained to ensure accuracy.[77] Ambulatory blood pressure monitoring over 12 to 24 hours is the most accurate method to confirm the diagnosis.[78]
The new guidelines stem from the 2017 results of the Systolic Blood Pressure Intervention Trial (SPRINT), which studied more than 9,000 adults ages 50 and older who had systolic blood pressure (the top number in a reading) of 130 mm Hg or higher and at least one risk factor for cardiovascular disease. The study's aim was to find out whether treating blood pressure to lower the systolic number to 120 mm Hg or less was superior to the standard target of 140 mm Hg or less. The results found that targeting a systolic pressure of no more than 120 mm Hg reduced the chance of heart attacks, heart failure, or stroke over a three-year period.
Dietary changes: The health care provider might recommend a diet that includes more vegetables (especially leafy green vegetables), fruits, low-fat dairy products, and fiber-rich foods, and fewer carbohydrates, fats, processed foods, and sugary drinks. He or she also might recommend preparing low-sodium dishes and not adding salt to foods. Watch out for foods with lots of hidden salt (like bread, sandwiches, pizza, and many restaurant and fast-food options).
Orthostasis literally means standing upright. Orthostatic hypotension, or postural hypotension, is defined as a decrease in systolic blood pressure of at least 20 mm Hg or at least 10mm Hg within 3 minutes of the patient standing. If orthostatic hypotension is present, the client may be at risk of falls and should be closely supervised with ambulation or advised to call for assistance with activity.
Stage 1 and Stage 2 hypertensions require therapy with anti-hypertensive drugs to bring down the blood pressure. Lifestyle modifications are also necessary, but often it is not sufficient for satisfactory control of blood pressure. Hypertension is often asymptomatic in the early course of disease. Symptoms like headache, lightheadedness, palpitations and easy fatigability may occur and chances of them being present increases with increasing blood pressure.
The measurements must have been obtained from at least two careful readings on at least two different occasions. What does careful mean? The guidelines provide a six-step tutorial on how, exactly, to correctly measure a blood pressure, which, admittedly, is sorely needed. My patients often have their first blood pressure taken immediately after they have rushed in through downtown traffic, as they’re sipping a large caffeinated beverage. While we always knew this could result in a falsely elevated measurement, it is now officially poor clinical technique resulting in an invalid reading.
Hypertension, the medical term for high blood pressure, is known as "the silent killer." More than 80 million Americans (33%) have high blood pressure, and as many as 16 million of them do not even know they have the condition. If left untreated, high blood pressure greatly increases your risk for heart attack and stroke. Hypertension is projected to increase about 8 percent between 2013 and 2030.
An abnormally fast heart rate (tachycardia) also can cause low blood pressure. The most common example of tachycardia causing low blood pressure is atrial fibrillation (Afib). Atrial fibrillation is a disorder of the heart characterized by rapid and irregular electrical discharges from the muscle of the heart causing the ventricles to contract irregularly and (usually) rapidly. The rapidly contracting ventricles do not have enough time to fill maximally with blood before each contraction, and the amount of blood that is pumped decreases in spite of the faster heart rate. Other abnormally rapid heart rhythms such as ventricular tachycardia also can produce low blood pressure, and sometimes life-threatening shock.
Your blood pressure is considered high when you have consistent systolic readings of 140 mm Hg or higher or diastolic readings of 90 mm Hg or higher. Based on research, your doctor may also consider you to have high blood pressure if you are an adult or child age 13 or older who has consistent systolic readings of 130 to 139 mm Hg or diastolic readings of 80 to 89 mm Hg and you have other cardiovascular risk factors.
Allergic reaction (anaphylaxis): Anaphylactic shock is a sometimes-fatal allergic reaction that can occur in people who are highly sensitive to drugs such as penicillin, to certain foods such as peanuts or to bee or wasp stings. This type of shock is characterized by breathing problems, hives, itching, a swollen throat and a sudden, dramatic fall in blood pressure.