Low blood pressure is diagnosed by a doctor when they check your blood pressure with a sphygmomanometer. For people who experience low blood pressure without other symptoms, it may only require regular monitoring by a doctor during routine exams, and medical treatment may not be necessary. If certain signs suggest an underlying condition, your doctor may recommend one or more of the following tests to diagnose a cause for your hypotension:
The range of systolic blood pressure for most healthy adults falls between 90 and 120 millimeters of mercury (mm Hg). Normal diastolic blood pressure ranges between 60 and 80 mm Hg. Current guidelines define normal blood pressure range as lower than 120/80. Blood pressures over 130/80 are considered high. High blood pressure increases the risk of damaging the arteries, which leads to the development of:
Rates of high blood pressure in children and adolescents have increased in the last 20 years in the United States.[147] Childhood hypertension, particularly in pre-adolescents, is more often secondary to an underlying disorder than in adults. Kidney disease is the most common secondary cause of hypertension in children and adolescents. Nevertheless, primary or essential hypertension accounts for most cases.[148]
ACE (angiotensin converting enzyme) inhibitors are another class of antihypertensive drugs. They reduce the body's levels of angiotensin II, a substance that narrows blood vessels. This means that arteries are more open (dilated) and the blood pressure is lower. ACE inhibitors can be used alone, or with other medications such as diuretics. Side effects of ACE inhibitors can include skin rash, dry cough, dizziness, and elevated potassium levels. Women who are pregnant, planning to get pregnant, or breastfeeding should not take ACE inhibitors.
Effective lifestyle modification may lower blood pressure as much as an individual antihypertensive medication. Combinations of two or more lifestyle modifications can achieve even better results.[87] There is considerable evidence that reducing dietary salt intake lowers blood pressure, but whether this translates into a reduction in mortality and cardiovascular disease remains uncertain.[96] Estimated sodium intake ≥6g/day and <3g/day are both associated with high risk of death or major cardiovascular disease, but the association between high sodium intake and adverse outcomes is only observed in people with hypertension.[97] Consequently, in the absence of results from randomized controlled trials, the wisdom of reducing levels of dietary salt intake below 3g/day has been questioned.[96] 

Recent updates to guidelines from the American Heart Association and the American College of Cardiology changed the definition of high blood pressure or hypertension for most people. High blood pressure is now generally defined as 130 or higher for the first number, or 80 or higher for the second number (previously it was 140/90). However, there are important considerations for older adults in deciding whether to start treatment for high blood pressure, including other health conditions and overall fitness. If your blood pressure is above 130/80, your doctor will evaluate your health to determine what treatment is needed to balance risks and benefits in your particular situation.
High blood pressure is more common in older people. At age 45, more men have hypertension than women. By age 65, this is reversed and more women are affected. People with diabetes have a greater risk of hypertension than those without diabetes. Having a close family member with high blood pressure also increases your risk of developing it. About 60% of all people with diabetes also have hypertension.
There are even more medication types that can lower blood pressure. Some of these are alpha blockers, vasodilators, and central alpha agonists. Your doctor may prescribe these medications if other medications have been ineffective or if you have another condition along with hypertension. Side effects can include fast pulse, palpitations, dizziness, diarrhea, or headaches.
It is important to go to your regular check-ups with your doctor. Hypertension is a common condition and, if caught, can be treated with medication to prevent complications. However, if you experience any of the symptoms of hypertension, such as frequent headaches, recurrent dizziness, nosebleeds, shortness of breath, nausea or vomiting, don't wait—speak to your doctor immediately.

^ Qaseem A, Wilt TJ, Rich R, Humphrey LL, Frost J, Forciea MA (17 January 2017). "Pharmacologic Treatment of Hypertension in Adults Aged 60 Years or Older to Higher Versus Lower Blood Pressure Targets: A Clinical Practice Guideline From the American College of Physicians and the American Academy of Family Physicians". Annals of Internal Medicine. 166 (6): 430–437. doi:10.7326/M16-1785. PMID 28135725.
3. Implement strategies to lower inflammation. Several cross-sectional and longitudinal studies connect high blood pressure with chronic inflammation, a driving force for nearly every disease on the planet. Lowering inflammation starts with what you put on your fork. Focus on anti-inflammatory foods like wild-caught seafood (rich in omega-3 fatty acids), freshly ground flax and chia seeds, spices like turmeric, and plenty of colorful plant foods. Good sleep, stress management, exercise, and the right nutrients can also help lower inflammation.
Medications used to lower blood pressure include diuretics (e.g., hydrochlorothiazide*), beta-blockers (e.g., atenolol, metoprolol), ACE inhibitors (e.g., ramipril, enalapril, lisinopril), calcium channel blockers (e.g., nifedipine, amlodipine), angiotensin II receptor blockers (e.g., losartan, valsartan), and direct renin inhibitors (e.g., aliskiren).
Pulse pressure (the difference between systolic and diastolic blood pressure) is frequently increased in older people with hypertension. This can mean that systolic pressure is abnormally high, but diastolic pressure may be normal or low a condition termed isolated systolic hypertension.[59] The high pulse pressure in elderly people with hypertension or isolated systolic hypertension is explained by increased arterial stiffness, which typically accompanies aging and may be exacerbated by high blood pressure.[60]
The brain requires unobstructed blood flow to nourish its many functions. Very high, sustained blood pressure will eventually cause blood vessels to weaken. Over time these weaken vessels can break, and blood will leak into the brain. The area of the brain that is being fed by these broken vessels start to die, and this will cause a stroke. Additionally, if a blot clot blocks a narrowed artery, blood ceases to flow and a stroke will occur.
Enlarged heart. High blood pressure increases the amount of work for your heart. Like any heavily exercised muscle in your body, your heart grows bigger (enlarges) to handle the extra workload. The bigger your heart is, the more it demands oxygen-rich blood but the less able it is to maintain proper blood flow. As a result, you feel weak and tired and are not able to exercise or perform physical activities. Without treatment, your heart failure will only get worse.

Although it's most common in older adults, hypertension can also affect children. The normal blood pressure for a child is dependent upon the child's age, gender, and height. Your doctor can tell if your child's blood pressure is abnormal. Children are at higher risk for hypertension if they are overweight, African-American, or if they have a family history of the condition. Children with high blood pressure may benefit from the DASH diet and taking medications. Children with high blood pressure should also maintain a healthy weight and avoid tobacco smoke.
Meschia JF, Bushnell C, Boden-Albala B, et al; American Heart Association Stroke Council; Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; Council on Functional Genomics and Translational Biology; Council on Hypertension.. Guidelines for the primary prevention of stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2014;45(12):3754-3832. PMID: 25355838 www.ncbi.nlm.nih.gov/pubmed/25355838.
Excellent point! I can’t speak for anyone specifically, but I can say that generally, doctors make the worst patients. We don’t always follow the textbook guidelines nor abide by health recommendations. Then, there’s genetics, a pretty powerful force, and one over which we have little control. And, of course, there is just plain bad luck (or fate, finger of God, however you choose to describe it). So, many factors can come into play when a doctor gets diagnosed with what can otherwise be considered a preventable disease.
Postural hypotension occurs most frequently in people who are taking drugs to control high blood pressure (hypertension). It can also be related to pregnancy, strong emotions, hardening of the arteries (atherosclerosis), or diabetes. The elderly are particularly affected, especially those who have high blood pressure or autonomic nervous system dysfunction.
"Having a healthy lifestyle really makes a difference in your life because you can avoid high blood pressure," said Dr. Mary Ann Bauman, an internist at Integris Baptist Medical Center in Oklahoma City. "If you do have high blood pressure, make sure take your medication. You may not necessarily have symptoms until your blood pressure gets really high."

With age, comes an increased risk for systolic hypertension which can be aggravated by severe atherosclerosis. According to one study, the diuretic chlorthalidone (Hygroton) had significant benefit in elderly patients with systolic hypertension. Along with a diuretic, some calcium channel blockers, ACE inhibitors and angiotensin II receptor blockers may also be good choices. However, beta blockers may not be as effective for hypertension in those over 60; though they may be good choices if co-existing heart disease is present. It also may be preferable in elderly patients to give two high blood pressure medications at a low dose versus one at a higher dose.
In normal blood pressure for elderly & adults over 50, increased systolic blood pressure is a major risk factor for heart disease. Systolic blood pressure tends to increase steadily over time due to stiff arteries, a build-up of plaque, and a higher rate of cardiac and vascular disease. This means older adults need to be even more vigilant about monitoring their blood pressure.
Postural (orthostatic) hypotension is a sudden drop in blood pressure when an individual stands up from a sitting, squatting, or supine (lying) position. When a person stands up, gravity causes blood to settle in the veins in the legs so that less blood returns to the heart for pumping, and, as a result, the blood pressure drops. The body normally responds automatically to the drop in blood pressure by increasing the rate and narrowing the veins to return more blood to the heart. In patients with postural hypotension, this compensating reflex fails to occur, resulting low blood pressure and its symptoms. Postural hypotension can occur in persons of all ages but is much more common among the elderly, especially in those on medications for high blood pressure and/or diuretics. Other causes of postural hypotension include dehydration, adrenal insufficiency, prolonged bed rest, diabetes, and certain rare neurological syndromes (for example, Shy-Drager syndrome) that damage the autonomic nerves.
4. Find an exercise that works for you (and do it). Moving more can help reverse high blood pressure. One meta-analysis of 65 studies found regular exercise provides both an acute and longer-term reduction in blood pressure. Whether you’re an exercise novice or a conditioned athlete, these four strategies can help you create an effective workout plan to optimize health.
Blood pressure is given as a reading of two numbers, such as 110/70. The higher number (systolic) is the pressure when the heart beats. The diastolic, or lower number shows the pressure between the heartbeats, while the relaxed heart is refilling with blood. Normal blood pressure readings are lower than 120/80. The cause of most hypertension is unknown. Occasionally, conditions of the kidney or adrenal gland are the cause of high blood pressure.
The kidney can respond to changes in blood pressure by increasing or decreasing the amount of urine that is produced. Urine is primarily water that is removed from the blood. When the kidney makes more urine, the amount (volume) of blood that fills the arteries and veins decreases, and this lowers blood pressure. If the kidneys make less urine, the amount of blood that fills the arteries and veins increases and this increases blood pressure. Compared with the other mechanisms for adjusting blood pressure, changes in the production of urine affect blood pressure slowly over hours and days. (The other mechanisms are effective in seconds.)
In short, everyone. The motivation behind the change was to make people healthier. With more sensitive guidelines, we are able to get in control of our blood pressure sooner and improve heart health before reaching levels that could cause more serious health problems. For some, the changing guidelines may result in antihypertensive (blood pressure lowering) medication, along with lifestyle management, but that will not be the case for everyone.
Medicines are available if these changes do not help control your blood pressure within 3 to 6 months. Diuretics help rid your body of water and sodium. ACE inhibitors block the enzyme that raises your blood pressure. Other types of medicines— beta blockers, calcium channel blockers, and other vasodilators—work in different ways, but their overall effect is to help relax and widen your blood vessels and reduce the pressure inside the vessel. [See also the free government publication “Medicines to Help You: High Blood Pressure” (PDF) from the US Food and Drug Administration.]
"The implications and potential benefits of such healthier lifestyles could be great, particularly since about 22% of the adult population falls into the prehypertensive category," says Chobanian, who is also dean of the Boston University School of Medicine. "In fact, the blood pressure effects of weight reduction or adoption of the DASH eating plan can be comparable to those achieved with any single blood pressure medication."
It wasn’t long ago (2013) that those over 60 were advised to aim for blood pressure below 150/90. Now, as a result of a single large trial, the numbers are being revised in a major way. But as Dr. Gilbert Welch has pointed out at https://www.nytimes.com/2017/11/15/opinion/blood-pressure-guidelines.html , there are problems with this study. First, about 8% of patients aiming for 140 systolic (or less) had “cardiovascular events,” whereas only 6% of those in the 120 systolic group did. This is only a 2 point reduction, but as a percentage it’s a 25% reduction. This is the misleading use of percentage change instead of actual change. Second, the participants were already at higher than average risk for cardiovascular problems, so it was a study of a selected group and not of the general population.
The cuff is placed around the upper arm and inflated with an air pump to a pressure that blocks the flow of blood in the main artery that travels through the arm. The arm is held at the side of the body at the level of the heart, and the pressure of the cuff is gradually released. As the pressure decreases, a health practitioner listens with a stethoscope over the artery at the front of the elbow or an electronic machine senses the pulsation. The pressure at which the practitioner (or machine) first hears a pulsation from the artery is the systolic pressure (the top number). As the cuff pressure decreases further, the pressure at which the pulsation finally stops is the diastolic pressure (the bottom number).

Blood pressure rises with aging and the risk of becoming hypertensive in later life is considerable.[37] Several environmental factors influence blood pressure. High salt intake raises the blood pressure in salt sensitive individuals; lack of exercise, obesity, and depression[38] can play a role in individual cases. The possible roles of other factors such as caffeine consumption,[39] and vitamin D deficiency[40] are less clear. Insulin resistance, which is common in obesity and is a component of syndrome X (or the metabolic syndrome), is also thought to contribute to hypertension.[41] One review suggests that sugar may play an important role in hypertension and salt is just an innocent bystander.[42]

An exception to this is those with very high blood pressure readings especially when there is poor organ function.[79] Initial assessment of the hypertensive people should include a complete history and physical examination. With the availability of 24-hour ambulatory blood pressure monitors and home blood pressure machines, the importance of not wrongly diagnosing those who have white coat hypertension has led to a change in protocols. In the United Kingdom, current best practice is to follow up a single raised clinic reading with ambulatory measurement, or less ideally with home blood pressure monitoring over the course of 7 days.[79] The United States Preventive Services Task Force also recommends getting measurements outside of the healthcare environment.[80] Pseudohypertension in the elderly or noncompressibility artery syndrome may also require consideration. This condition is believed to be due to calcification of the arteries resulting in abnormally high blood pressure readings with a blood pressure cuff while intra arterial measurements of blood pressure are normal.[81] Orthostatic hypertension is when blood pressure increases upon standing.[82]
Various expert groups have produced guidelines regarding how low the blood pressure target should be when a person is treated for hypertension. These groups recommend a target below the range 140–160 / 90–100 mmHg for the general population.[13][99][100][101][102] Cochrane reviews recommend similar targets for subgroups such as people with diabetes[103] and people with prior cardiovascular disease.[104]

How the heart pumps blood into the arteries with enough force to push blood to the far reaches of each organ from the top of the head to the bottom of the feet. Blood pressure can be defined as the pressure of blood on the walls of the arteries as it circulates through the body. Blood pressure is highest as its leaves the heart through the aorta and gradually decreases as it enters smaller and smaller blood vessels (arteries, arterioles, and capillaries). Blood returns in the veins leading to the heart, aided by gravity and muscle contraction.
On physical examination, hypertension may be associated with the presence of changes in the optic fundus seen by ophthalmoscopy.[22] The severity of the changes typical of hypertensive retinopathy is graded from I to IV; grades I and II may be difficult to differentiate.[22] The severity of the retinopathy correlates roughly with the duration or the severity of the hypertension.[20]
Systolic BP lower than 90 mm Hg or diastolic BP lower than 60 mm Hg is considered low blood pressure or hypotension. Unlike hypertension, hypotension is more likely to be due to a primary cause (dehydration, heart disease, drugs, endocrine disease, etc.) and thus therapy is often aimed at treating the primary cause. Borderline BP with no obvious cause can be treated with increased salt and water intake, regular mild exercises, cutting down on alcohol, etc.). Drug therapy can be used if such hypotension is not amenable to these measures.
Recurrent headaches: Headaches are fairly common among people with or without hypertension. Some people with hypertension notice changes or worsening of headaches when medications are skipped or when the blood pressure becomes higher than usual. Headaches associated with hypertension can be mild, moderate, or severe and can be of a throbbing nature. 
Blood pressure is the force exerted by circulating blood on the walls of blood vessels. It constitutes one of the critically important signs of life or vital signs, which include heart rate, breathing, and temperature. Blood pressure is generated by the heart pumping blood into the arteries modified by the response of the arteries to the flow of blood.
"The implications and potential benefits of such healthier lifestyles could be great, particularly since about 22% of the adult population falls into the prehypertensive category," says Chobanian, who is also dean of the Boston University School of Medicine. "In fact, the blood pressure effects of weight reduction or adoption of the DASH eating plan can be comparable to those achieved with any single blood pressure medication."