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.
High blood pressure, or hypertension, occurs when the force of blood pushing through your vessels is consistently too high.
Low blood pressure, or hypotension, is when your blood pressure is lower than what’s considered normal.
What is high blood pressure?
Narrow blood vessels, also known as arteries, create more resistance for blood flow. The narrower your arteries are, the more resistance there is, and the higher your blood pressure will be. Over the long term, the increased pressure can cause health issues, including heart disease.
Hypertension is quite common and 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.
How to understand high blood pressure readings
Two numbers create a blood pressure reading. Systolic pressure (top number) indicates the pressure in your arteries when your heart beats and pumps out blood. Diastolic pressure (bottom number) is 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 like 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.
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:
- blood spots in the eyes
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 with 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.
There are two types of hypertension. Each type has a different cause.
Essential (primary) hypertension
Essential hypertension is also called primary hypertension. This kind of hypertension develops over time. Most people have this type of high blood pressure.
A combination of factors typically play a role in the development of essential hypertension:
- Genes: Some people are genetically predisposed to hypertension. This may be from gene mutations or genetic abnormalities inherited from your parents.
- Age: Individuals over 65 years old are more at risk for hypertension.
- Race: Black non-Hispanic individuals have a higher incidence of hypertension.
- Living with obesity: Living with obesity can lead to a few cardiac issues, including hypertension.
- High alcohol consumption: Women who habitually have more than one drink per day, and men who have more than two drinks per day, may be at an increased risk for hypertension.
- Living a very sedentary lifestyle: lowered levels of fitness have been connected to hypertension.
- Living with diabetes and/or metabolic syndrome: Individuals diagnosed with either diabetes or metabolic syndrome are at a higher risk of developing hypertension.
- high sodium intake: There’s a small association between daily high sodium intake (more than 1.5g a day) and hypertension.
Secondary hypertension often occurs quickly and can become more severe than primary hypertension. Several conditions that may cause secondary hypertension include:
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, like 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:
- 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
- home blood pressure monitor to monitor your blood pressure over a 24-hour period at home
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.
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.
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.
If your doctor discovers an underlying issue causing your hypertension, treatment will focus on that other condition. For example, if a medication you’ve started taking is causing increased blood pressure, your doctor will try other medications that don’t have this side effect.
Many people go through a trial-and-error phase with blood pressure medications. Your doctor may need to try different medications until they find one or a combination that works for you.
Healthy lifestyle changes can help you control the factors that cause hypertension. Here are some of the most common ones.
Developing a heart-healthy diet
A heart-healthy diet is vital for helping to reduce high blood pressure. It’s also important for managing hypertension that’s under control and reducing the risk of complications. These complications include heart disease, stroke, and heart attack. A heart-healthy diet emphasizes fruits, vegetables, whole grains and lean proteins.
Increasing physical activity
In addition to helping you lose weight (if your doctor has recommended it), exercise can help 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, 5 times per week.
Reaching an optimal weight
If you’re living with obesity, maintaining a moderate weight with 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 and include meditation, deep breathing, massage, muscle relaxation and yoga. Getting adequate sleep may also help reduce stress levels.
Quitting smoking and limiting alcohol
If you’re a smoker and have been diagnosed with high blood pressure, your doctor will most likely advise you to quit. The chemicals in tobacco smoke can 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. Drinking alcohol in excess can raise blood pressure.
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 which increases your risk for heart failure, arrhythmias, sudden cardiac death or heart attacks.
Your brain relies on a healthy supply of oxygen-rich blood to work properly. Untreated 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. But it does lower the risks for future problems.
To help make sure every part of your body — including the brain, heart, and lungs — is getting plenty of blood and oxygen, your blood pressure naturally changes during the day.
Your body constantly adjusts and balances your blood pressure. The position of your body may impact your blood pressure. For example, if you stand up suddenly, it may drop for an instant. Your blood pressure also lowers when you’re resting or asleep.
So, low blood pressure may not be a cause for concern or come with any other worrisome symptoms.
On the other hand, some health conditions can result in low blood pressure. This can lead to too little blood and oxygen in some parts of the body. Treating the underlying condition helps to raise blood pressure.
The symptoms of low blood pressure can include:
- blurred vision
- feeling cold
- feeling thirsty
- an inability to concentrate
- rapid, shallow breathing
Low blood pressure from medications, shock, or stroke
Some medications can cause low blood pressure.
Shock is a life threatening condition. It can happen in response to a number of emergency conditions. These include a heart attack or stroke, serious injury or burn, severe infection, allergic reaction or blood clots.
Shock leads to low blood pressure, but low blood pressure can also cause your body to go into shock. Treatment may involve raising blood pressure by IV fluids or blood transfusions.
Treating the cause of the shock often helps to raise blood pressure.
Stroke is a leading cause of death. It’s also a major cause of serious and long-term disability.
High blood pressure is a major cause of stroke. It’s important to control blood pressure to prevent strokes, and to keep them from happening again.
If you’re dealing with hypotension, the first step is making an appointment with your doctor. After discussing your medical history, lifestyle, and other factors, your doctor may change your medication or suggest certain lifestyle changes to get to the root of the issue.
It’s important not to stop taking any medications or change dosages without talking to a healthcare professional first. The same is true of dietary or other changes.
1. Drink plenty of water
Dehydration can sometimes lead to low blood pressure. Some people may have hypotension even with mild dehydration.
You can also get dehydrated by losing water too quickly. This can happen through vomiting, severe diarrhea, fever, strenuous exercise, and excess sweating.
2. Eat a balanced diet
Low blood pressure and other side effects may occur if you’re not getting enough nutrients.
Low levels of vitamin B12, folic acid, and iron can cause anaemia. This condition happens when your body can’t make enough blood and can cause low blood pressure.
Your doctor may recommend changes to your daily diet and taking supplements.
3. Eat smaller meals
You can get low blood pressure after eating a big meal, although this is more common in older adults. This happens because blood flows to your digestive tract after you eat. Normally, your heart rate increases to help balance blood pressure.
4. Limit or avoid alcohol
Drinking alcohol can lead to dehydration. It can also interact with medications and cause low blood pressure.
5. Eat more salt
Sodium helps to raise blood pressure. However, it can raise blood pressure too much. It can also lead to heart disease. Ask your doctor how much is right for you.
6. Check your blood sugar
Diabetes and high blood sugar levels may lead to low blood pressure. Volume depletion can occur from the diuresis that follows high blood sugar levels. This is when your body tries to expel glucose via increased urination.
Consider using a home monitor to check your blood sugar levels throughout the day. See your doctor to find out the best diet, exercise, and medication plan to help balance blood sugar levels.
7. Get your thyroid checked
Thyroid conditions are common. Hypothyroidism occurs when you don’t produce enough thyroid hormones and this can lead to low blood pressure.
A simple blood test can determine whether you have hypothyroidism. You may need medication and a new nutrition plan to help boost your thyroid function.
8. Wear compression stockings
Elastic stockings or socks can help prevent blood from pooling in your legs. This helps to relieve orthostatic or postural hypotension which is low blood pressure due to standing, laying down, or sitting too much.
9. Take medications
Your doctor may prescribe medications to help treat low blood pressure. These drugs help to treat orthostatic hypotension.
If someone’s BP is dangerously low from sepsis, other medications may be used to raise blood pressure.
10. Treat infections
Some serious bacterial, viral, and fungal infections can cause low blood pressure. Your doctor can find out if you have an infection with a blood test. Treatment includes IV antibiotics and antiviral drugs.
There are several causes of low blood pressure. Some are temporary and can be easily fixed. Low blood pressure may also be a sign of a health issue or emergency condition. Treatment may be necessary.
Several health conditions can cause low blood pressure. These include:
Diagnosing and treating these conditions can help balance blood pressure. Your doctor may recommend simple tests such as:
Having low blood pressure once in a while isn’t likely a cause for concern.
Tell your doctor about any related symptoms. Keep a journal of your symptoms and what you were doing when they began.
This can help your doctor diagnose the cause of your low blood pressure, especially if you’ve tried making changes to your diet and lifestyle and still aren’t seeing your BP at a healthy level.