The majority of the U.S. adult population is affected by at least one chronic condition, most prominently cardiovascular disease, diabetes, obesity and cancer. Chronic diseases tend to accumulate, cascading to additional complications, lower quality of life, and premature mortality. Once a person develops one chronic disease, they are at high risk of developing additional ones.
The co-occurrence of 2 or more chronic diseases is known as multimorbidity. People with multiple chronic diseases have substantially higher disability and mortality risks than those with just 1 chronic disease. One of the few longitudinal studies of multi-morbidity, from Europe found that, at age 60, people with 1 cardiometabolic disease had life expectancy 6-10 years shorter than people with no disease, while people with 2 and 3 diseases had life expectancies 12 and 15 years shorter, respectively. People with multimorbidity also have higher care needs and medical costs than people with just 1 chronic condition.