Health Basics: Chronic Disease
Learn what chronic disease means, which conditions are most common, what factors contribute to them, and how they can be managed over time.
Reviewed by K.M. Venkat Narayan, MD, MSc, MBA, and Christine Laine, MD, MPH. Last updated September 24, 2025.
Chronic diseases affect 6 in 10 American adults, and 4 in 10 live with more than one of these conditions. Not all chronic diseases are preventable, but some conditions and their complications can be delayed or avoided by addressing common risk factors: tobacco use, poor nutrition, physical inactivity, and excessive alcohol use. Early detection and treatment also help to improve outcomes.
What is a chronic disease?
A chronic disease is a . These diseases typically develop slowly over time and may persist for the rest of a person’s life. Unlike acute illnesses, such as a urinary tract infection or pneumonia, chronic diseases often cannot be cured, but they can be managed. The term “chronic disease” includes a wide range of conditions, from heart disease and diabetes to arthritis and asthma. Some cancers also meet the definition of chronic disease. Chronic diseases can affect people of all ages, although they become more common with age: . Living with one or more chronic conditions can make health management complex and costly.
Chronic diseases can affect people of all ages, although they become more common with age. Photo: M Stocker via Shutterstock
What are the most common chronic diseases?
As of 2025, the most common in the United States include coronary heart disease, stroke, cancer, type 2 diabetes, chronic obstructive pulmonary disease, asthma, Alzheimer’s disease, hypertension, and chronic kidney disease. These conditions affect tens of millions of people nationwide and contribute to long-term disability. Overall, chronic diseases account for 8 out of 10 and .
How can chronic diseases be prevented and which aren’t avoidable through behavior?
Many—but not all—chronic diseases can be prevented or significantly delayed through healthy behaviors. For example, coronary heart disease, type 2 diabetes, and certain cancers are strongly linked to factors such as tobacco use, poor nutrition, physical inactivity, and alcohol consumption. Adopting habits like quitting smoking, eating a balanced good quality diet, maintaining a healthy weight, staying active, regular sleep, and keeping up with recommended screenings can .
However, some conditions cannot currently be prevented by lifestyle choices. is an autoimmune disease with complex genetic and environmental triggers and exist at this time. The same is true of other autoimmune conditions such as rheumatoid arthritis and thyroid disease. Other chronic conditions, such as , are influenced by factors like air pollution or allergens. While symptom management and mitigation are possible, primary prevention through individual behaviors is limited.
While many chronic diseases respond positively to healthy habits, others require medical monitoring, medical interventions, and public health interventions to reduce risk or manage progression.
Medical monitoring and intervention can help manage chronic conditions. Photo: Prostock-studio via Shutterstock
What are the causes of chronic diseases?
Chronic diseases often develop due to a combination of genetic, behavioral, environmental, and social factors. Common behavioral risk factors include tobacco use, poor nutrition, lack of physical activity, poor sleep, and excessive alcohol consumption. —like air pollution or contact with harmful chemicals—can also play a role, especially in respiratory and cardiovascular diseases. In addition, genetics, family history, and mother’s nutrition and health during pregnancy, may increase an individual’s susceptibility to some chronic conditions. , such as limited access to affordable health care, nutritious food, stable housing, and education, further influence a person’s risk and ability to manage disease. These factors often interact in complex ways over time.
How do chronic diseases affect daily life?
Chronic diseases can significantly impact a person’s day-to-day life in physical, emotional, and financial ways. Physically, these conditions may cause such as pain, fatigue, and reduced mobility, making it harder to carry out daily tasks or maintain independence. The long-term nature of chronic illness can also affect mental health, contributing to stress, anxiety, or depression. In addition, the cost of ongoing medical care, medications, and impact on the ability to work can place a financial burden on individuals and their families.
Chronic diseases can significantly impact a person’s day-to-day life in physical, emotional, and financial ways. Photo: Ljupco Smokovski via Shutterstock
What is the economic impact of chronic conditions?
Chronic conditions impose a massive economic burden in the United States, accounting for . In 2016 alone, direct health care —with major contributors including diabetes, Alzheimer’s disease, and osteoarthritis. Obesity-related conditions . When factoring in lost productivity, chronic diseases may cost the United States .
What is the chronic disease rate in the United States vs. other countries?
The United States experiences a . Analyses across high-income countries—including Australia, Canada, Germany, Japan, and the UK—show the United States consistently leads in rates of obesity, hypertension, diabetes, chronic obstructive pulmonary disease (COPD), asthma, kidney disease, depression, and cancer. These disparities reflect differences in health behaviors, health care systems, social policies, prevalence of risk factors, and socioeconomic conditions.
Has the rate of chronic disease in the United States increased over time?
From 2013 to 2023, the share of US adults reporting at least one chronic condition . The rate of those living with . Children and young adults also face rising rates of chronic illness.
What chronic conditions are most common among children?
Chronic conditions are increasingly prevalent among US children and adolescents, (about 25 million individuals ages 5 to 25). These conditions include attention-deficit/hyperactivity disorder, asthma, type 1 diabetes, obesity, depression and anxiety, among others. Obesity alone now . Some but not all chronic conditions prevalent in children are preventable via healthy behaviors.
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Disclaimer: The information provided on this website is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition.
