We all know that Red is the color of the blood which flows through our veins. Our Blood is red because it has red pigment colored pigment called hemoglobin. Blood consists of plasma, red blood cells, white blood cells, and platelets. Blood helps in the formation of oxygen, carbon dioxide, digested foods, etc. from body parts to other parts. Blood helps in the formation of oxygen, regulates the digestive system etc. It saves us from dangerous blood diseases and also regulates blood temperature.
What is blood pressure?
The strength to carry blood through blood vessels leads to pressure which is known as blood pressure. Therefore, we can define blood pressure as the pressure with which the blood is spread around the body by the heart. 
If the blood pressure is high then there is a high of pressure in the arteries of the heart and may also lead to heart attack. This can cause a heart attack. Hence it is very important for you to keep your blood pressure normal. 

What is normal blood pressure? 
In the contraction phase, the maximum pressure through which cardiac blood leaves the main artery is called Systolic Pressure. The minimum pressure of the arteries during the heart relaxes or expansion phase is called diastolic of the arteries during the heart relaxes or expansion phase 
There are two types of blood pressure. 
Systolic Pressure –     120 mmHg    
Diastolic Pressure –     80 mmHg

Therefore the normal blood pressure is 120/80 but it can vary from time to time. 

Risk of High Blood Pressure 
High Blood pressure is also called as Hypertension. This is due to the contraction of the arteries. This increases the resistance of blood flow. This might damage the arteries and also cause internal bleeding. It also causes many health problems. 

How is Blood Pressure Measured?
Blood Pressure is measured by Sphygmomanometer. The following are the steps to measure blood pressure.

Attach the cuff the cuff and ensure that it is the correct size. After that wrap the cuff around the arm and then line up with the brachial artery.

Palpate your radial pulse; inflate the cuff until the pulse disappears. Note down the reading of the sphygmomanometer. This is the rough estimation of the systolic blood pressure. 

Now palpate the brachial artery, place the stethoscope over the brachial artery and re-inflate the cuff to 20-30 mmHg above your roughly estimated systolic blood pressure. Slowly deflate the cuff, at some point you will begin to hear a thumping sound. The first sound you hear is the systolic blood pressure. 

Continue to deflate the cuff, listen carefully until the sound disappears that will be the diastolic blood pressure. 

This is how you generally measure blood pressure.