Human: What are the most common diseases and their causes? Assistant: 
The most common diseases include heart disease, stroke, cancer, diabetes, Alzheimer's disease, arthritis, asthma, allergies, and depression. Heart disease is caused by a combination of genetic factors, high blood pressure, cholesterol levels, smoking, obesity, physical inactivity, and stress. Stroke is caused by a combination of genetics, hypertension, diabetes, smoking, diet, alcohol consumption, and physical activity. Cancer can be caused by a combination of genetics, lifestyle, environment, and exposure to certain chemicals or radiation. Diabetes is caused by a combination of genetics, unhealthy eating habits, lack of exercise, and being overweight. Alzheimer’s disease is caused by a combination of genetics, environmental factors such as head trauma, and lifestyle factors such as smoking and drinking alcohol. Arthritis is caused by a combination of genetics, age, weight, joint injury, and inflammation. Asthma is caused by a combination of genetic predisposition, environmental triggers like dust mites and pet dander, and lifestyle factors such as smoking and air pollution. Allergies are caused by a combination of genes, environmental allergens, and lifestyle choices. Depression is caused by a combination of genetics, brain chemistry, life events, and social support.