What Is Blood Pressure? – Levels Of Blood Pressure, Prevention, Treatment
Blood pressure is one of the vital signs, along with respiratory rate, heart rate, oxygen saturation, and body temperature. Normal resting blood pressure, in an adult is approximately 120 millimetres of mercury (16 kPa) systolic, and 80 millimetres of mercury (11 kPa) diastolic, abbreviated “120/80 mmHg”. Globally, the average blood pressure, age standardized, has remained about the same since 1975 to the present, at approx. 127/79 mmHg in men and 122/77 mmHg in women, although these average data mask quite large divergent regional trends.
What Is Blood Pressure?
Blood pressure (BP) is the pressure of circulating blood on the walls of blood vessels. Most of this pressure is due to work done by the heart by pumping blood through the circulatory system. Used without further specification, “blood pressure” usually refers to the pressure in large arteries of the systemic circulation. Blood pressure is usually expressed in terms of the systolic pressure (maximum during one heartbeat) over diastolic pressure (minimum in between two heartbeats) and is measured in millimeters of mercury (mmHg), above the surrounding atmospheric pressure.
Traditionally, blood pressure was measured non-invasively using auscultation with a mercury-tube sphygmomanometer.Auscultation is still generally considered to be the gold standard of accuracy for non-invasive blood pressure readings in clinic.However, semi-automated methods have become common, largely due to concerns about potential mercury toxicity,although cost, ease of use and applicability to ambulatory blood pressure or home blood pressure measurements have also influenced this trend.Early automated alternatives to mercury-tube sphygmomanometers were often seriously inaccurate, but modern devices validated to international standards achieve an average difference between two standardized reading methods of 5 mm Hg or less and a standard deviation of less than 8 mm Hg.Most of these semi-automated methods measure blood pressure using oscillometry.
Blood pressure is influenced by cardiac output, total peripheral resistance and arterial stiffness and varies depending on situation, emotional state, activity, and relative health/disease states. In the short term, blood pressure is regulated by baroreceptors which act via the brain to influence the nervous and the endocrine systems.
Levels Of Blood Pressure
Blood pressure that is too low is called hypotension, pressure that is consistently high is called hypertension and normal levels of blood pressure is called normotension.Both hypertension and hypotension have many causes and may be of sudden onset or of long duration. Long-term hypertension is a risk factor for many diseases, including heart disease, stroke and kidney failure. Long-term hypertension is more common than long-term hypotension, which is usually only diagnosed when it causes symptoms.
High Blood Pressure(Hypertension)
High blood pressure, or hypertension, occurs when your blood pressure increases to unhealthy levels. Your blood pressure measurement takes into account how much blood is passing through your blood vessels and the amount of resistance the blood meets while the heart is pumping.
Narrow arteries increase resistance. The narrower your arteries are, the higher your blood pressure will be. Over the long term, increased pressure can cause health issues, including heart disease.
Hypertension is quite common. In fact, since the guidelines have recently changed, it’s expected that nearly half of American adults will now be diagnosed with this condition.
Hypertension typically develops over the course of several years. Usually, you don’t notice any symptoms. But even without symptoms, high blood pressure can cause damage to your blood vessels and organs, especially the brain, heart, eyes, and kidneys.
Early detection is important. Regular blood pressure readings can help you and your doctor notice any changes. If your blood pressure is elevated, your doctor may have you check your blood pressure over a few weeks to see if the number stays elevated or falls back to normal levels.
Treatment for hypertension includes both prescription medication and healthy lifestyle changes. If the condition isn’t treated, it could lead to health issues, including heart attack and stroke.
What are the symptoms of hypertension?
Hypertension is generally a silent condition. Many people won’t experience any symptoms. It may take years or even decades for the condition to reach levels severe enough that symptoms become obvious. Even then, these symptoms may be attributed to other issues.
Symptoms of severe hypertension can include:
- shortness of breath
- chest pain
- visual changes
- blood in the urine
These symptoms require immediate medical attention. They don’t occur in everyone with hypertension, but waiting for a symptom of this condition to appear could be fatal.
The best way to know if you have hypertension is to get regular blood pressure readings. Most doctors’ offices take a blood pressure reading at every appointment.
If you only have a yearly physical, talk to your doctor about your risks for hypertension and other readings you may need to help you watch your blood pressure.
For example, if you have a family history of heart disease or have risk factors for developing the condition, your doctor may recommend that you have your blood pressure checked twice a year. This helps you and your doctor stay on top of any possible issues before they become problematic.
What causes high blood pressure?
There are two types of hypertension. Each type has a different cause.
Primary hypertension is also called essential hypertension. This kind of hypertension develops over time with no identifiable cause. Most people have this type of high blood pressure.
Researchers are still unclear what mechanisms cause blood pressure to slowly increase. A combination of factors may play a role. These factors include:
- Genes: Some people are genetically predisposed to hypertension. This may be from gene mutations or genetic abnormalities inherited from your parents.
- Physical changes: If something in your body changes, you may begin experiencing issues throughout your body. High blood pressure may be one of those issues. For example, it’s thought that changes in your kidney function due to aging may upset the body’s natural balance of salts and fluid. This change may cause your body’s blood pressure to increase.
- Environment: Over time, unhealthy lifestyle choices like lack of physical activity and poor diet can take their toll on your body. Lifestyle choices can lead to weight problems. Being overweight or obese can increase your risk for hypertension.
Secondary hypertension often occurs quickly and can become more severe than primary hypertension. Several conditions that may cause secondary hypertension include:
- kidney disease
- obstructive sleep apnea
- congenital heart defects
- problems with your thyroid
- side effects of medications
- use of illegal drugs
- alcohol abuse or chronic use
- adrenal gland problems
- certain endocrine tumors
Diagnosing high blood pressure
Diagnosing hypertension is as simple as taking a blood pressure reading. Most doctors’ offices check blood pressure as part of a routine visit. If you don’t receive a blood pressure reading at your next appointment, request one.
If your blood pressure is elevated, your doctor may request you have more readings over the course of a few days or weeks. A hypertension diagnosis is rarely given after just one reading. Your doctor needs to see evidence of a sustained problem. That’s because your environment can contribute to increased blood pressure, such as the stress you may feel by being at the doctor’s office. Also, blood pressure levels change throughout the day.
If your blood pressure remains high, your doctor will likely conduct more tests to rule out underlying conditions. These tests can include:
- urine test
- cholesterol screening and other blood tests
- test of your heart’s electrical activity with an electrocardiogram (EKG, sometimes referred to as an ECG)
- ultrasound of your heart or kidneys
These tests can help your doctor identify any secondary issues causing your elevated blood pressure. They can also look at the effects high blood pressure may have had on your organs.
During this time, your doctor may begin treating your hypertension. Early treatment may reduce your risk of lasting damage.
How to understand high blood pressure readings
Two numbers create a blood pressure reading:
- Systolic pressure: This is the first, or top, number. It indicates the pressure in your arteries when your heart beats and pumps out blood.
- Diastolic pressure: This is the second, or bottom, number. It’s the reading of the pressure in your arteries between beats of your heart.
Five categories define blood pressure readings for adults:
- Healthy:A healthy blood pressure reading is less than 120/80 millimeters of mercury (mm Hg).
- Elevated:The systolic number is between 120 and 129 mm Hg, and the diastolic number is less than 80 mm Hg. Doctors usually don’t treat elevated blood pressure with medication. Instead, your doctor may encourage lifestyle changes to help lower your numbers.
- Stage 1 hypertension: The systolic number is between 130 and 139 mm Hg, or the diastolic number is between 80 and 89 mm Hg.
- Stage 2 hypertension: The systolic number is 140 mm Hg or higher, or the diastolic number is 90 mm Hg or higher.
- Hypertensive crisis: The systolic number is over 180 mm Hg, or the diastolic number is over 120 mm Hg. Blood pressure in this range requires urgent medical attention. If any symptoms such as chest pain, headache, shortness of breath, or visual changes occur when blood pressure is this high, medical care in the emergency room is needed.
A blood pressure reading is taken with a pressure cuff. For an accurate reading, it’s important you have a cuff that fits. An ill-fitting cuff may deliver inaccurate readings.
Blood pressure readings are different for children and teenagers. Ask your child’s doctor for the healthy ranges for your child if you’re asked to monitor their blood pressure.
A number of factors help your doctor determine the best treatment option for you. These factors include which type of hypertension you have and what causes have been identified.
Primary hypertension treatment options
If your doctor diagnoses you with primary hypertension, lifestyle changes may help reduce your high blood pressure. If lifestyle changes alone aren’t enough, or if they stop being effective, your doctor may prescribe medication.Secondary hypertension treatment options
If your doctor discovers an underlying issue causing your hypertension, treatment will focus on that other condition. For example, if a medicine you’ve started taking is causing increased blood pressure, your doctor will try other medicines that don’t have this side effect.
Sometimes, hypertension is persistent despite treatment for the underlying cause. In this case, your doctor may work with you to develop lifestyle changes and prescribe medications to help reduce your blood pressure.
Treatment plans for hypertension often evolve. What worked at first may become less useful over time. Your doctor will continue to work with you to refine your treatment.
Many people go through a trial-and-error phase with blood pressure medications. You may need to try different medicines until you find one or a combination of medications that work for you.
Some of the medications used to treat hypertension include:
- Beta-blockers: Beta-blockers make your heart beat slower and with less force. This reduces the amount of blood pumped through your arteries with each beat, which lowers blood pressure. It also blocks certain hormones in your body that can raise your blood pressure.
- Diuretics: High sodium levels and excess fluid in your body can increase blood pressure. Diuretics, also called water pills, help your kidneys remove excess sodium from your body. As the sodium leaves, extra fluid in your bloodstream moves into your urine, which helps lower your blood pressure.
- ACE inhibitors: Angiotensin is a chemical that causes blood vessels and artery walls to tighten and narrow. ACE (angiotensin converting enzyme) inhibitors prevent the body from producing as much of this chemical. This helps blood vessels relax and reduces blood pressure.
- Angiotensin II receptor blockers (ARBs): While ACE inhibitors aim to stop the creation of angiotensin, ARBs block angiotensin from binding with receptors. Without the chemical, blood vessels won’t tighten. That helps relax vessels and lower blood pressure.
- Calcium channel blockers: These medications block some of the calcium from entering the cardiac muscles of your heart. This leads to less forceful heartbeats and a lower blood pressure. These medicines also work in the blood vessels, causing them to relax and further lowering blood pressure.
- Alpha-2 agonists: This type of medication changes the nerve impulses that cause blood vessels to tighten. This helps blood vessels to relax, which reduces blood pressure.
Home remedies for high blood pressure
Healthy lifestyle changes can help you control the factors that cause hypertension. Here are some of the most common home remedies.
Developing a healthy diet
A heart-healthy diet is vital for helping to reduce high blood pressure. It’s also important for managing hypertension that is under control and reducing the risk of complications. These complications include heart disease, stroke, and heart attack.
A heart-healthy diet emphasizes foods that include:
- whole grains
- lean proteins like fish
Increasing physical activity
Reaching a healthy weight should include being more physically active. In addition to helping you shed pounds, exercise can help reduce stress, lower blood pressure naturally, and strengthen your cardiovascular system.
Aim to get 150 minutes of moderate physical activity each week. That’s about 30 minutes five times per week.
Reaching a healthy weight
If you are overweight or obese, losing weight through a heart-healthy diet and increased physical activity can help lower your blood pressure.
Exercise is a great way to manage stress. Other activities can also be helpful. These include:
- deep breathing
- muscle relaxation
- yoga or tai chi
These are all proven stress-reducing techniques. Getting adequate sleep can also help reduce stress levels.
Adopting a cleaner lifestyle
If you’re a smoker, try to quit. The chemicals in tobacco smoke damage the body’s tissues and harden blood vessel walls.
If you regularly consume too much alcohol or have an alcohol dependency, seek help to reduce the amount you drink or stop altogether. Alcohol can raise blood pressure.
One of the easiest ways you can treat hypertension and prevent possible complications is through your diet. What you eat can go a long way toward easing or eliminating hypertension.
Here are some of the most common dietary recommendations for people with hypertension.
Eat less meat, more plants
A plant-based diet is an easy way to increase fiber and reduce the amount of sodium and unhealthy saturated and trans fat you take in from dairy foods and meat. Increase the number of fruits, vegetables, leafy greens, and whole grains you’re eating. Instead of red meat, opt for healthier lean proteins like fish, poultry, or tofu.
Reduce dietary sodium
People with hypertension and those with an increased risk for heart disease may need to keep their daily sodium intake between 1,500 milligrams and 2,300 milligrams per day. The best way to reduce sodium is to cook fresh foods more often. Avoid eating restaurant food or prepackaged foods, which are often very high in sodium.
Cut back on sweets
Sugary foods and beverages contain empty calories but don’t have nutritional content. If you want something sweet, try eating fresh fruit or small amounts of dark chocolate that haven’t been sweetened as much with sugar. Studies Trusted Source suggest regularly eating dark chocolate may reduce blood pressure.
High blood pressure during pregnancy
Women with hypertension can deliver healthy babies despite having the condition. But it can be dangerous to both mother and baby if it’s not monitored closely and managed during the pregnancy.
Women with high blood pressure are more likely to develop complications. For example, pregnant women with hypertension may experience decreased kidney function. Babies born to mothers with hypertension may have a low birth weight or be born prematurely.
Some women may develop hypertension during their pregnancies. Several types of high blood pressure problems can develop. The condition often reverses itself once the baby is born. Developing hypertension during pregnancy may increase your risk for developing hypertension later in life.
In some cases, pregnant women with hypertension may develop preeclampsia during their pregnancy. This condition of increased blood pressure can cause kidney and other organ complications. This can result in high protein levels in the urine, problems with liver function, fluid in the lungs, or visual problems.
As this condition worsens, the risks increase for the mother and baby. Preeclampsia can lead to eclampsia, which causes seizures. High blood pressure problems in pregnancy remain an important cause of maternal death in the United States. Complications for the baby include low birth weight, early birth, and stillbirth.
There is no known way to prevent preeclampsia, and the only way to treat the condition is to deliver the baby. If you develop this condition during your pregnancy, your doctor will closely monitor you for complications.
What are the effects of high blood pressure on the body?
Because hypertension is often a silent condition, it can cause damage to your body for years before symptoms become obvious. If hypertension isn’t treated, you may face serious, even fatal, complications.
Complications of hypertension include the following.
Healthy arteries are flexible and strong. Blood flows freely and unobstructed through healthy arteries and vessels.
Hypertension makes arteries tougher, tighter, and less elastic. This damage makes it easier for dietary fats to deposit in your arteries and restrict blood flow. This damage can lead to increased blood pressure, blockages, and, eventually, heart attack and stroke.
Hypertension makes your heart work too hard. The increased pressure in your blood vessels forces your heart’s muscles to pump more frequently and with more force than a healthy heart should have to.
This may cause an enlarged heart. An enlarged heart increases your risk for the following:
- heart failure
- sudden cardiac death
- heart attack
Your brain relies on a healthy supply of oxygen-rich blood to work properly. High blood pressure can reduce your brain’s supply of blood:
- Temporary blockages of blood flow to the brain are called transient ischemic attacks (TIAs).
- Significant blockages of blood flow cause brain cells to die. This is known as a stroke.
Uncontrolled hypertension may also affect your memory and ability to learn, recall, speak, and reason. Treating hypertension often doesn’t erase or reverse the effects of uncontrolled hypertension. It does, however, lower the risks for future problems.
High blood pressure: Tips for prevention
If you have risk factors for hypertension, you can take steps now to lower your risk for the condition and its complications.
Add healthy foods to your diet
Slowly work your way up to eating more servings of heart-healthy plants. Aim to eat more than seven servings of fruits and vegetables each day. Then aim to add one more serving per day for two weeks. After those two weeks, aim to add one more serving. The goal is to have ten servings of fruits and vegetables per day.
Adjust how you think of the average dinner plate
Instead of having meat and three sides, create a dish that uses meat as a condiment. In other words, instead of eating a steak with a side salad, eat a bigger salad and top it with a smaller portion of steak.
Try to incorporate fewer sugar-sweetened foods, including flavored yogurts, cereals, and sodas. Packaged foods hide unnecessary sugar, so be sure to read labels.
Set weight loss goals
Instead of an arbitrary goal to “lose weight,” talk with your doctor about a healthy weight for you. The Centers for Disease Control and Prevention (CDC)Trusted Source recommends a weight loss goal of one to two pounds a week. That means starting off eating 500 calories less per day than what you normally eat. Then decide on what physical activity you can start in order to reach that goal. If exercising five nights a week is too hard to work into your schedule, aim for one more night than what you’re doing right now. When that fits comfortably into your schedule, add another night.
Monitor your blood pressure regularly
The best way to prevent complications and avoid problems is to catch hypertension early. You can come into your doctor’s office for a blood pressure reading, or your doctor may ask you to purchase a blood pressure cuff and take readings at home.
Keep a log of your blood pressure readings and take it to your regular doctor appointments. This can help your doctor see any possible problems before the condition advances.
Low Blood Pressure(Hypotension)
Hypotension is low blood pressure. Your blood pushes against your arteries with each heartbeat. And the pushing of the blood against the artery walls is called blood pressure.
Having a lower blood pressure is good in most cases (less than 120/80). But low blood pressure can sometimes make you feel tired or dizzy. In those cases, hypotension can be a sign of an underlying condition that should be treated.
Blood pressure is measured when your heart beats, and in the periods of rest between heartbeats. The measurement of your blood pumping through your arteries when the ventricles of the heart squeeze is called systolic pressure or systole. The measurement for the periods of rest is called diastolic pressure, or diastole.
Systole supplies your body with blood, and diastole supplies your heart with blood by filling the coronary arteries. Blood pressure is written with the systolic number above the diastolic number. Hypotension in adults is defined as blood pressure of 90/60 or lower.
What causes hypotension?
Everyone’s blood pressure drops at one time or another. And, it often doesn’t cause any noticeable symptoms. Certain conditions can cause prolonged periods of hypotension that can become dangerous if left untreated. These conditions include:
- pregnancy, due to an increase in demand for blood from both mother and the growing fetus
- large amounts of blood loss through injury
- impaired circulation caused by heart attacks or faulty heart valves
- weakness and a state of shock that sometimes accompanies dehydration
- anaphylactic shock, a severe form of allergic reaction
- infections of the bloodstream
- endocrine disorders such as diabetes, adrenal insufficiency, and thyroid disease
Medications might also cause blood pressure to drop. Beta-blockers and nitroglycerin, used to treat heart disease, are common culprits. Diuretics, tricyclic antidepressants, and erectile dysfunction drugs can also cause hypotension.
Some people have low blood pressure for unknown reasons. This form of hypotension, called chronic asymptomatic hypotension, isn’t usually harmful.
People with hypotension may experience symptoms when their blood pressure drops below 90/60. Symptoms of hypotension can include:
- clammy skin
- loss of consciousness
- blurry vision
Symptoms can range in severity. Some people may be slightly uncomfortable, while others may feel quite ill.
Types of hypotension
Hypotension is divided into several different classifications according to when your blood pressure drops.
Orthostatic hypotension is the drop in blood pressure that occurs when you transition from sitting or lying down to standing. It is common in people of all ages.
As the body adjusts to the position change there may be a brief period of dizziness. This is what some people refer to as “seeing stars” when they get up.
Postprandial hypotension is a drop in blood pressure that occurs right after eating. It is a type of orthostatic hypotension. Older adults, especially those with Parkinson’s disease, are more likely to develop postprandial hypotension.
Neurally mediated hypotension happens after you stand for a long time. Children experience this form of hypotension more often than adults. Emotionally upsetting events can also cause this drop in blood pressure.
Severe hypotension is related to shock. Shock occurs when your organs do not get the blood and oxygen they need to function properly. Severe hypotension can be life-threatening if not treated promptly.
Treatment for hypotension
Your treatment will depend on the underlying cause of your hypotension. Treatment could include medications for heart disease, diabetes, or infection.
Drink plenty of water to avoid hypotension due to dehydration, especially if you are vomiting or have diarrhea.
Staying hydrated can also help treat and prevent the symptoms of neurally mediated hypotension. If you experience low blood pressure when standing for long periods, be sure to take a break to sit down. And try to reduce your stress levels to avoid emotional trauma.
Treat orthostatic hypotension with slow, gradual movements. Instead of standing up quickly, work your way into a sitting or standing position using small movements. You can also avoid orthostatic hypotension by not crossing your legs when you sit.
Shock-induced hypotension is the most serious form of the condition. Severe hypotension must be treated immediately. Emergency personnel will give you fluids and possibly blood products to increase your blood pressure and stabilize your vital signs.
Low Blood Pressure:Tips For Prevention
Most people can manage and prevent hypotension by understanding the condition and being educated about it. Learn your triggers and try to avoid them. And, if you’re prescribed medication, take it as directed to increase your blood pressure and to avoid potentially harmful complications.
And remember, it’s always best to notify your doctor if you are concerned about your blood pressure levels and any symptoms you have.