disease, heart failure, peripheral vascular disease, and cardiomyopathy. Cardiovascular disease is known as the world's biggest killer. 17.5 million people die from it each year, which equals 31% of all deaths. Heart disease and stroke cause 80% of these deaths. Risk factors High blood pressure is the leading risk factor for cardiovascular disease and has contributed to 12% of the cardiovascular related deaths worldwide. Other significant risk factors for heart disease include high cholesterol and smoking. 47% of all Americans have one of these three risk factors. Lifestyle choices, such as poor diet and physical inactivity, and excessive alcohol use can also contribute to cardiovascular disease. Medical conditions, like diabetes and obesity can also be risk factors. Prevalence in countries of affluence In the United States, 610,000 people die every year from heart disease which is equal to 1 in 4 deaths. The leading cause of death for both men and women in the United States is heart disease. In Canada, heart disease is the second leading cause of death. In 2014, it was the cause of death for 51,000 people. In Australia, heart disease is also the leading cause of death. 29% of deaths in 2015, had an underlying cause of heart disease. Heart disease causes one in four premature deaths in the United Kingdom and in 2015 heart disease caused 26% of all deaths in that country. People of lower socio-economic status are more likely to have cardiovascular disease than those who have a higher socio-economic status. This inequality gap has occurred in developed countries because people who have a lower socio-economic status often face many of the risk factors of tobacco and alcohol use, obesity as well as having a sedentary lifestyle. Further social and environmental factors such as poverty, pollution, family history, housing and employment contribute to this inequality gap and to risk of having a health condition caused by cardiovascular disease. The increasing inequality gap between the higher and lower income populations continues in countries such as Canada, despite the availability of health care for everyone. Alzheimer's disease and other dementias Dementia is a chronic syndrome which is characterized by deterioration in the thought process beyond what is expected from normal aging. It affects the persons memory, thinking, orientation, comprehension, behavior and ability to perform everyday activity. There are many different forms of dementia . Alzheimer is the most common form which contributes to 60–70%