Blood Pressure: When Are Values in the Normal Range?
It is estimated that about 18% of Italians suffer from high blood pressure, with prevalence progressively increasing as age increases, rising to more than 50% over age 74. Keeping blood pressure under control is fundamental to keeping the heart healthy. In fact, high blood pressure increases the risk of heart diseases such as heart attack and stroke.
What is Blood Pressure?
Blood pressure is the force with which blood is pushed by the heart pump into the vessels; it is called arterial pressure (BP) if it is arteries, or venous pressure if it is veins. The higher the pressure, the more work (and fatigue) the heart has to do.
Why High Blood Pressure is a Problem
High blood pressure can damage arteries and cause several diseases.
Heart disease
When plaque builds up inside the arteries due to high blood pressure, it can lead to atherosclerosis. When this happens, the arteries narrow and harden, reducing the flow of blood and oxygen to the heart.
Reduced blood flow can also result in:
- Heart attack.
- Heart failure.
- Chest pain, known as angina.
Stroke
High blood pressure is also one of the risk factors for stroke-one of the leading causes of death and disability-which occurs when brain cells die because they do not receive enough oxygen. The most common type of stroke is ischemic stroke, which is when arteries fail to supply enough blood, and therefore oxygen, to the brain. High blood pressure can increase the risk of developing a brain aneurysm, which can cause a hemorrhagic stroke or brain hemorrhage.
Aneurysm
An aneurysm occurs when the wall of a weakened artery swells or widens. It can be the result of years of uncontrolled blood pressure, which over time puts extra pressure on the artery walls.
Symptoms depend on the location of the aneurysm and may include:
- Increased heart rate.
- Dizziness or headache.
- Low blood pressure.
- Nausea or vomiting.
- Moist skin.
- Feeling that something is wrong.
A rapidly enlarging or bursting aneurysm can be fatal.
Plaque formation
Plaque is a substance composed of fat, cholesterol and calcium. It can accumulate in arteries over time causing them to narrow and restrict blood flow to the heart. Excessive accumulation of plaque can lead to very serious medical conditions, such as heart attack or stroke.
Kidney disease
High blood pressure can damage blood vessels in the kidneys by reducing their blood flow. Damaged kidneys have a harder time eliminating waste and excess fluid from the body, which in turn can further increase blood pressure leading to kidney failure.
Dementia
As we age, 'hypertension is linked to dementia and the process of cognitive decline.
Understanding Blood Pressure Values
The blood pressure value is composed of two numbers measured in millimeters of mercury (mm Hg):
Systolic pressure
This is the pressure in the arteries when the heart beats. It is the higher number because the arteries are under greater pressure.
Diastolic pressure
This is the pressure between heart beats. It is the lower number because the arteries are subjected to less pressure between beats.
Blood pressure is classified into five categories.
Normal blood pressure (< 120/80 mmHg) (H3)
Elevated blood pressure (120-129/< 80 mmHg)
If blood pressure is elevated, it is more likely to develop hypertension if appropriate measures are not taken.
Stage 1 hypertension (130-139 mmHg sysotolic, or 80-89 mmHg diastolic)
If values are within these ranges, the physician may prescribe medication to reduce blood pressure.
Stage 2 hypertension
Occurs when systolic blood pressure is often 140 mm Hg or higher or diastolic blood pressure is often 90 mm Hg or higher. The doctor may prescribe medication to reduce blood pressure.
Hypertensive crisis
Hypertensive crisis requires medical attention. It occurs when systolic blood pressure is above 180 mm Hg and/or diastolic blood pressure is above 120.
Call your doctor right away if you have an elevated value, even in the absence of symptoms.
Learn more about Cardiology Services at UPMC Salvator Mundi International Hospital.