Hypertension, often called "the silent killer", is a medical condition that does not strike fear into the hearts of many people. Why? It often presents no noticeable symptoms.
Many people (myself included) don't feel the need to go to the doctor until they have (unbearable) symptoms of something being "wrong". It is a fair assumption then that if they are not going for regular check-ups with a healthcare provider, they are probably not monitoring blood pressure levels on their own either. It is also likely that some are even unaware that their blood pressure is at an unhealthy level.