Medical information can get outdated quickly, and some of these articles are a decade old. Thus, in addition to the usual cautions (this web page is not your doctor, and has no legal obligation to provide accurate, personalized medical advice; plus the usual caveats about every article on this website), please notice the dates on these articles. Chemistry, physics, and basic physiology don't change; but explanations of diseases often do, usually in small ways but sometimes in large ways. The best available treatments for diseases change even more quickly, as new drugs and procedures become available (or become discredited). In particular, though it is not generally accepted, I regard the material here on heart disease, cholesterol, and diet as being of much less interest than it used to be, due to recent results which implicate infection (and in particular the bacterium Chlamydia pneumoniae) as the cause of atherosclerosis, and suggest that it can be cured by appropriate antibiotic treatment (as per these pioneering efforts). But since the articles collected here are not mere propaganda, but contain discussions of the evidence and reasoning for the view that diet and lifestyle are the main culprits, they retain considerable interest.