What is Blood Pressure?
When the heart beats, it pumps blood for the whole body giving it energy and oxygen it requires. As the blood circulates and transported from one body part to other via the blood vessels (or arteries), it pushes against the sides. The strength of this pushing is known as blood pressure. Blood pressure is the highest as it leaves the heart through the aorta and gradually decreases as it enters smaller and narrower blood vessels (arteries, arterioles and capillaries). Blood returns back to heart via veins, aided by muscle contraction and gravity. The pressure of the blood passing through the vessels changes at different times in the heartbeat cycle, as the heart. When the heart is contracting the pressure will be the highest and lowest when it relaxes before the pumping process begins.
Blood pressure reading appears as two numbers. The higher and first of the two is a measure of ‘systolic pressure’ (the pressure in the arteries when the heart beats and fills with blood) and the second number measures ‘diastolic pressure’ (pressure in the arteries when the heart rests between beats).
The American Heart Association has laid down guidelines to define normal and high blood pressure, which states:
- Normal Blood Pressure is less than 120/80 mm Hg
- Pre-hypertension is between 120-139/ 80-89 mm Hg
- High blood pressure (Stage 1) lies between 140-159/ 90-99 mm Hg
- High blood pressure (Stage 2) is higher than 160/ 100 mm Hg
- Hypertensive Crisis is higher than 180 mm Hg
Ideally, we should all have a blood pressure below 120 and over 80 (120/80) on the meter reading for good health and lower risk of heart disease or stroke.
What is High Blood Pressure?
High blood pressure or hypertension means that blood pressure is higher than the normal recommended level. One of the most dangerous aspects of this condition is that you may not even know that you are suffering from it. In fact, nearly one out of three people who have high BP have no idea about it. If not treated over time, the heart may enlarge making it pump less blood and leading to heart failure.
If your blood pressure is way over the line, there may be certain symptoms to look out for, which include
- Irregular heartbeat
- Difficulty breathing
- Severe headache
- Pounding in your chest, neck, or ears
- Fatigue or confusion
- Vision problems
- Chest pain
- Blood in the urine
Often labeled as the ‘silent killer’, this condition can be fatal if not treated at the earliest. People often seek medical care only when symptoms arise from organ damage, which is caused by chronic (long term, ongoing) high blood pressure. The following are the types of organ damage commonly seen in patients with suffering from long term high BP
- Heart attack
- Stroke or transient ischemic attack (TIA)
- Heart failure
- Eye damage with lowering of vision progressively
- Kidney failure
- Claudication, a peripheral arterial disease that results in leg pain while walking
- Aneurysms- is bulging of the aorta
Malignant hypertension is caused to almost 1% of the total people suffering from high B.P. Here, the diastolic blood pressure (the lower number reading on the BP meter) often exceeds 140 mm Hg. This condition is often associated with lightheadedness, continuous headaches, vomiting and nausea. Immediate emergency intervention is needed if experienced to prevent brain hemorrhage and heart stokes. It is of utmost importance to understand that high blood pressure can be unrecognized for years, causing no symptoms but progressive damage to the heart, blood vessels and other organs.
What is Low Blood Pressure?
Low blood pressure or hypotension is the medical term when the blood pressure reading is less than 90/60 mm Hg. This condition has symptoms which are almost never serious. However, if the blood pressure drops suddenly, the brain is deprived of adequate blood supply leading to lightheadedness or dizziness. Commonly, abrupt drop in the pressure happens when someone rises from a prone or sitting position to standing. This type of low blood pressure is known as ‘postural or orthostatic hypotension’. If one stands for too long, another type of low blood pressure can occur, known as ‘neutrally mediated hypotension’.
Postural hypotension is most likely to occur due to the failure of cardiovascular or nervous system to react in response to sudden changes. Under normal conditions, when one stands up, the blood pools to the lower extremities. If not maintained well by the body, this would cause blood pressure to fall. But the body normally compensates by sending messages to the heart signaling to beat faster and the vessels to constrict. This process offsets the blood pressure drop, resulting in postural hypotension. Both, low and high blood pressure risks increase with age as the blood flow to the brain and heart muscles decline. This can happen due to plaque buildup in the blood vessels. An estimated 10%-15% people over the age of 65 have postural hypotension.
There is a reason why blood pressure is termed as the silent killer. The symptoms associated with this condition can escape one’s notice very easily but the disease itself is wrecking enough to leave some of the most vital body functions severely impaired.
It is important to bear in mind that these symptoms may be mistaken for an ailment in themselves or for some other disease. The best method to diagnose this condition and if you have already noticed this symptom, you should see a doctor at the earliest.