Hypertension, or High Blood Pressure, is a condition where our blood is pumped around the body at a higher than normal pressure over a prolonged period of time. Hypertension is a common problem. In Singapore, almost one in 4 aged 30 to 69 years have hypertension.
Hypertension can be categorised based on a patient’s systolic blood pressure and diastolic blood pressure levels.
Systolic blood pressure (top number) refers to your blood pressure at the point where your heart’s contraction is strongest.
Diastolic blood pressure (bottom number) refers to your blood pressure when your heart is at its most relaxed state between heartbeats.
|Category||Systolic BP||Diastolic BP|
|Normal blood pressure||< 130 mmHg||< 85 mmHg|
|High-normal blood pressure||130 to 139 mmHg||85 to 89 mmHg|
|Grade 1 Hypertension||140 to 159 mmHg*||90 to 99 mmHg|
|Grade 2 Hypertension||160 to 179 mmHg*||100 to 109 mmHg|
|Grade 3 Hypertension||≥ 180 mmHg*||≥ 110 mmHg|
|Isolated Systolic Hypertension||≥ 140 mmHg*||< 90 mmHg|
In this chart, mmHg refers to millimetres of mercury, a unit of measure.
*When the systolic BP and diastolic BP fall under different categories, the higher category applies.
- Normal blood pressure
A normal blood pressure reading indicates that no treatment is necessary. However, it is still important that you monitor your blood pressure, especially as you age.
- Pre-hypertensive (High-normal blood pressure)
A blood pressure reading within the high-normal blood pressure range indicates that you may be at risk of developing hypertension. Medications may not be necessary, however, your doctor may advise you on changes you could make to your lifestyle in order to lower your blood pressure.
Any reading above Grade 1 Hypertension (140/90mmHg) indicates that you are hypertensive. Your doctor may recommend treatment, such as medication and lifestyle changes in order to lower your blood pressure and prevent further complications.
Do note that a diagnosis of hypertension must be confirmed with a doctor.
Certain non-modifiable factors may put you at risk of having high blood pressure. These include:
- Family history
If your parents or close relatives have hypertension, you may be genetically predisposed to develop hypertension.
As we age, our blood vessels become stiffer, which could contribute to high blood pressure.
There are also modifiable factors that put you at risk of having hypertension. These are factors you can change to help prevent and manage hypertension:
- Lack of physical activity
Not getting enough physical activity as part of your lifestyle increases your risk of getting hypertension. Physical activity is great for your heart and circulatory system
- Being obese or overweight
Carrying too much weight puts an extra strain on your heart and circulatory system that can cause serious health problems. It also increases your risk of cardiovascular disease, diabetes and hypertension
- An unhealthy diet, especially one high in sodium
A diet that is too high in salt, as well as calories, saturated and trans fat and sugar, carries an additional risk of hypertension. On the other hand, having a healthy diet can actually help lower blood pressure.
- Too much alcohol
Consuming too much alcohol on a regular basis can increase your blood pressure dramatically and lead to other serious health issues.
Smoking raises your blood pressure temporarily and causes damage to your artery walls. Even secondhand smoke increases the risk of cardiovascular diseases for nonsmokers.
Too much stress may contribute to increased blood pressure. Also, too much stress can encourage unhealthy lifestyles that increase blood pressure, such as poor diet, physical inactivity, smoking, or drinking alcohol more than usual.
Hypertension increases your risk of developing atherosclerosis, which is cholesterol plaque build up causing hardening and narrowing of your arteries, limiting the oxygen-rich blood to your heart and other parts of the body.
If untreated or inadequately treated, hypertension may lead to serious health complications such as:
- Coronary artery disease
- Heart failure
- Heart attack
- Peripheral artery disease
- Kidney failure
- Vision loss
- Aneurysm of the aorta
- Sexual dysfunction
Primary (essential) hypertension
In the majority of people, there is no identifiable cause of high blood pressure. This type of high blood pressure, called primary (essential) hypertension, tends to develop gradually over many years.
A smaller number of people have high blood pressure caused by an underlying condition. This type of high blood pressure, called secondary hypertension, tends to appear suddenly and cause higher blood pressure than does primary hypertension. Various conditions and medications can lead to secondary hypertension, including:
- Obstructive sleep apnea
- Kidney disease
- Adrenal gland tumours
- Thyroid problems
- Certain congenital defects in blood vessels
- Certain medications
Hypertension is often called the silent killer. This is because it may not give rise to any obvious symptoms, even when severe. Many people with high blood pressure do not even know they have it.
Sometimes, hypertension is only discovered when a related complication happens, for example, a heart attack or a stroke.
Very infrequently, you may experience headaches or giddiness when the hypertension is severe. However, these symptoms are not specific to hypertension; they are inconclusive and could be symptoms of other health conditions.
If you suspect you have hypertension, your doctor may recommend additional tests, such as:
- Ambulatory blood pressure monitoring (ABP)
Ambulatory blood pressure monitoring is performed usually over a 24-hour period with a small, portable blood pressure monitor. It measures your blood pressure at intervals automatically throughout the day. This test is useful to confirm the diagnosis of hypertension and to obtain a more accurate reading of your blood pressure changes throughout the day.
- Blood or urine tests
Your doctor may recommend blood or urine tests to check for any medical conditions related to hypertension.
- Electrocardiogram (ECG)
An ECG measures the electrical activity of your heart at rest and provides information on your heart rate and rhythm, and whether there are any effects of hypertension on the heart.
An echocardiogram uses sound waves to produce images of your heart. It allows an accurate assessment of the heart function and heart structure, and whether there are signs of heart disease related to hypertension.
- Exercise stress test
An exercise stress test, such as an exercise treadmill ECG, assesses how your heart functions during exercise stress. It may uncover heart-related issues arising from hypertension, and may also uncover exercise-induced hypertension.
Coronary artery disease and heart attack
High blood pressure causes excess strain and damages the walls of the arteries, leading to atherosclerosis (cholesterol plaque build-up). Atherosclerosis causes narrowings or blockages in the coronary arteries supplying blood to the heart muscle. This condition is known as coronary artery disease.
Severe narrowings may cause angina (or chest pain), decreased effort tolerance and may even trigger a heart attack. A heart attack is serious and may be life-threatening as parts of the heart muscle become damaged and unable to function.
Heart failure is a condition where your heart is unable to pump blood effectively to the rest of the body, and this can lead to swelling in your legs and fluid in your lungs, making it hard to breathe.
High blood pressure adds to your heart’s workload. The narrowed blood vessels caused by hypertension are less elastic, making it more difficult for the blood to travel smoothly and easily throughout your body. This causes your heart to work harder.
Over time, a higher workload leads to an enlarged heart. In order to cope with the higher workload, the heart muscle thickens (called left ventricular hypertrophy, or LVH) and becomes larger. The heart muscle becomes less efficient in pumping blood. The larger the heart becomes, the harder it has to work to meet your body’s demands for oxygen and nutrients.
Heart failure tends to get worse over time, but early diagnosis and treatment can help relieve symptoms and stop or delay the condition from getting worse. In an extremely weak heart, the heart may develop an abnormal and sometimes fatal arrhythmia (heart rhythm), causing a sudden cardiac arrest.
Prevention is better than cure. It is best to avoid high blood pressure altogether. Following a healthy lifestyle is a great place to start.
If you are diagnosed with hypertension, with proper treatment, you can control your blood pressure to help you live a long and healthy life.
Monitor your blood pressure regularly
If you are diagnosed with hypertension, you should monitor your blood pressure regularly. Tracking your blood pressure readings can alert you to any changes and help you detect patterns. Over time, it will also tell you if the treatment plan is working well.
Adopting a heart-healthy lifestyle
- Eat a well-balanced diet low in salt
- Enjoy regular physical activity
- Manage stress
- Maintain a healthy weight
- Quit smoking
- Limit alcohol
Work together with your doctor
It is vital that you listen to your doctor. You and your doctor are partners. Your doctor may prescribe blood pressure medications based on your condition and adjust accordingly. Your doctor will decide which medication is most suitable for you. Sometimes more than one medication may be prescribed. Take the medications that are prescribed for you.
Common types of blood pressure medications
- Angiotensin-converting enzyme (ACE) inhibitors — ACE inhibitors help the body produce less angiotensin, which helps the blood vessels relax and open up, and this helps to lower blood pressure.
- Angiotensin II receptor blockers (ARBs) — ARBs block receptors so the angiotensin fails to constrict the blood vessel. This means blood vessels stay open and blood pressure is reduced.
- Calcium channel blockers — Calcium channel blockers relax and open up narrowed blood vessels and lower blood pressure.
- Diuretics — Diuretics help the body get rid of excess sodium (salt) and water and help control blood pressure. They are often used in combination with other medications.
- Beta blockers — Beta-blockers reduce the heart rate, the heart’s workload and the heart’s output of blood, which lowers blood pressure.
If you are on medications for hypertension, do note that treatment is lifelong. Do not stop or change the dose of your medication without consulting your doctor. Make sure you see your doctor regularly to monitor your blood pressure. You can also monitor your blood pressure more frequently at home with an electronic blood pressure machine.
Remember, long-term effective control of blood pressure is crucial in reducing risks of serious complications of hypertension.
If you have hypertension, besides seeing your regular doctor to help manage your blood pressure, it is important to see a Cardiologist for a cardiovascular risk assessment because of the strong link between hypertension and heart disease.
It is vital to consult a Cardiologist if you have hypertension and are experiencing symptoms of chest discomfort or shortness of breath. If your blood pressure is not well controlled with your current set of medications, a Cardiologist may be consulted to help further optimize your treatment .
Depending on your condition, you may be recommended to undergo other tests to check your heart health, which could include:
Exercise stress treadmill ECG
Myocardial perfusion imaging (MPI)
CT coronary angiogram