A. 2. High blood pressure increases the chance of heart attack and disease, kidney disorder and dementia. A person suffering from high blood pressure is more prone to these diseases. As the blood exerts more pressure on the blood vessels, they become weaken or clogged. This makes the blood vessels constricted, or forming clots causing the insufficient supply of blood and oxygen to brain and heart. In rare occasions, the blood vessels rupture. High blood pressure can cause heart failure; this occurs when the heart is unable to pump enough blood through the body, causing swollen ankle, and breathlessness. High blood pressure can affect kidney, and vision also.