As we all know, high blood pressure is one of the widest spread diseases of our time. So, what is high blood pressure, and why is it so dangerous? Blood pressure is the force of the blood on the blood vessel walls and the higher that pressure is – the harder the heart has to work in order to continue pumping the blood. High blood pressure is also known as hypertension, and it’s usually not particularly dangerous when it’s isolated. The actual problem is when hypertension starts causing a bunch of other diseases, such as atherosclerosis, stroke and ultimately – heart failure.