These are some rather sobering statistics from the CDC in the US. You will notice they don't
even mention autoimmunity which is thought to be number 3 behind heart disease and cancer. PR
Chronic Diseases: The Leading Causes of Death and Disability in the United States
Chronic diseases and conditions—such as heart disease, stroke, cancer, diabetes, obesity, and arthritis—are among the most common, costly, and preventable of all health problems.
•As of 2012, about half of all adults—117 million people—have one or more chronic health conditions. One of four adults has two or more chronic health conditions.1
•Seven of the top 10 causes of death in 2010 were chronic diseases. Two of these chronic diseases—heart disease and cancer—together accounted for nearly 48% of all deaths.2
•Obesity is a serious health concern. During 2009–2010, more than one-third of adults, or about 78 million people, were obese (defined as body mass index [BMI] ≥30 kg/m2). Nearly one of five youths aged 2–19 years was obese (BMI ≥95th percentile).3
•Arthritis is the most common cause of disability.4 Of the 53 million adults with a doctor diagnosis of arthritis, more than 22 million say arthritis causes them to have trouble with their usual activities.5
•Diabetes is the leading cause of kidney failure, lower limb amputations other than those caused by injury, and new cases of blindness among adults.6