When you think of a serious or even deadly illness, you might jump to the most incurable ones that tend to grab newspaper headlines from time to time. However, those are not the very common serious illnesses we have in mind. These are the top 10 diseases that cause serious illnesses and even death: - Ischemic heart disease, or coronary artery disease - Stroke - Lower respiratory infections - Chronic obstructive pulmonary disease - Trachea, bronchus, and lung cancers - Diabetes mellitus - Alzheimer’s disease and other dementias - Dehydration due to diarrheal diseases - Tuberculosis - Cirrhosis