​​High blood pressure or hypertension is a silent killer that increases your risk of stroke, heart disease and other serious health complications if left unchecked.

Most people with high blood pressure feel normal (have no headaches or tightness in the neck, etc), even when their blood pressure is moderately high. Thus, many are not even aware that they have hypertension.

"This is why you should have your blood pressure checked at least once a year, and more frequently if you are on medication," says Dr Ian Phoon, Senior Consultant, SingHealth Polyclinics, a member of the SingHealth group.

Blood pressure measures how hard the heart has to work to pump blood through the arteries. ​According to the Health Promotion Board (HPB), high blood pressure affects more than half of Singaporeans aged 60 to 69 and about one in four aged 30 to 69. You have high blood pressure (hypertension) if your blood pressure reading is 140/90 mmHg or higher in the clinic.

If you have a home blood pressure set, you should check your blood pressure regularly, and record it. Blood pressure varies throughout the day, and taking your pressure at different times will allow your doctor to see your average blood pressure. Show this record to your doctor at each visit.

Here are 10 health reasons to keep your blood pressure under control:

1. High blood ​pressure can damage your arteries
   High blood pressure exerts extra force on the artery walls. Over time, it can damage your arteries (blood vessels) and make them more susceptible to plaque (fatty deposits) buildup, a condition called atherosclerosis. The hardened and narrowed arteries will disrupt blood flow to various organs in the body. Think of it as a clogged sink.
   
   
2. High blood pressure can cause heart disease
   Atherosclerosis causes arteries of the heart to thicken, blocking blood and oxygen supply to the heart muscles. You may experience chest pains or irregular heart rhythms (arrhythmias).​ A heart attack occurs when bloo​d clots completely block oxygen supply to the heart muscles. One out of three deaths in Singapore in 2011 was due to heart disease or stroke.
   
   
3. High blood pressure can damage your brain cells
   Blood clots may cut oxygen supply to the brain cells. This causes the brain cells to die and stroke or dementia to occur. The bursting of arteries in the brain may cause bleeding in the brain, resulting in a stroke.
   
   
4. High blood pre​ssure can affect your eyesight
   Uncontrolled high blood pressure causes the blood vessels in the eye to thicken and narrow, disrupting blood supply to the retina (the light-sensitive part of your eye – like a camera “film”). Blurred vision can result. The retinal veins may burst and cause bleeding in the eye. If blood pressure remains untreated, these conditions, known as hypertensive retinopathy, can lead to total vision loss.
   
   
5. High blood pressure (hypertension) can cause kidney failure​
   Hypertension (high blood pressure) can damage the arteries leading to the kidneys and the blood vessels in the kidneys. "This affects the kidneys’ ability to remove excess water and waste products from the blood. In turn, this may lead to kidney failure," says Dr Ian Phoon, Consultant, SingHealth Polyclinics (SHP), a member of the SingHealth group.
   
   
6. Hypertension m​ay cause sexual dysfunction
   In men, hypertension can cause erectile dysfunction (ED). It may make it more difficult for a man to have or maintain an erection due to reduced blood flow to the damaged penile arteries. Women with hypertension may experience vaginal dryness and lower sex drive.
   
   
7. Hypertension can cause bone loss
   People with hypertension tend to excrete more calcium in the urine. Excessive calcium loss can lead to loss in bone density. The body needs calcium to maintain strong bones and teeth, and help blood vessels move blood throughout the body.
   
   
8. Hypertension is associated with sleep problems
   People who are overweight and tend to snore may have obstructive sleep apnoea (OSA). This is a condition in which one repeatedly stops breathing momentarily or has shallow breathing during sleep. Symptoms are daytime sleepiness despite adequate hours of sleep. People with OSA tend to have higher blood pressure.
   
   
9. Hypertension is a sign of preeclampsia in pregnant women
   Preeclampsia, a condition characterised by hypertension (high blood pressure) and protein in the urine, affects a small percentage of pregnant women. Uncontrolled high blood pressure affects the unborn child’s growth as blo​od flow to the placenta reduces. Severe preeclampsia or eclampsia, where the mother suffers from seizures and convulsions, may develop.
   
   
10. Hypertension is one of the components of the metabolic syndrome
    Metabolic syndrome is a group of risk factors that increases your risk for heart disease and stroke. These factors include high blood pressure, excess abdominal fat, high cholesterol and high glucose levels.