The heart is a muscle about the size of your fist. It pumps blood around your body and beats approximately 70 times a minute. After the blood leaves the right side of the heart, it goes to your lungs where it picks up oxygen.
The oxygen-rich blood returns to your heart and is then pumped to the body's organs through a network of arteries. The blood returns to your heart through veins before being pumped back to your lungs again. This process is called circulation.
The heart gets its own supply of blood from a network of blood vessels on the heart's surface called coronary arterie
Being overweight may not be as unhealthy as it was 40 years ago," BBC News reports. New research has found a body mass index (BMI) of 27 is linked to the lowest rate of death – but someone with a BMI of 27 is currently classed as being overweight. BMI is a score calculated by dividing your weight (usually in kilograms) by the square of your height (usually in metres and centimetres). Currently, a BMI of 25 to 29.9 is classified as being overweight. Researchers looked at 120,528 people from Copenhagen, recruited from 1976 to 2013, and separately compared those recruited during the 1970s, 1990s and 2000s. They were followed up until they died, emigrated, or the study finished. The BMI linked to the lowest risk of having died from any cause was 23.7 in the 1970s group, 24.6 in the 1990s group, and had further risen to 27 in the 2003-13 group. It may be the case that the suggested upward shift in optimal BMI is the result of improvements in preventative treatments for weight-rela...