It gets even more complex, as there are people who develop type 1 later in life (I am still praying this isn't me, as my family has a history of LADA [latent autoimmune diabetes in adults]). Type 1 starts with autoimmune disorders  Your body gets mixed up, and your immune system decides it doesn't like the look of your pancreas and proceeds to kick its ass, killing it's beta cells (which produce insulin).  Welcome to the world of ZERO insulin production.  You are now fucked. Type 2, in individuals like me, starts with what is known as insulin resistance.  Basically most of your cells have little doors which can be unlocked to let glucose in.  In normal people, you stick insulin in the key hole, and kablammo!  It works.  Glucose gets into your cells.  But for some people, sometimes that doesn't work so well, and you end up having to use more, and more, and more, and more insulin to open the cell's doors.  Eventually, even though your body produces insulin, your blood sugar raises because your body can't get it into your cells. Your cells respond by saying "Pancreas!  We need more glucose!  Help us please!"  and the Pancreas says "You need MOAR insulin?  Ok!", but it has it's limits. Eventually Mr. Liver wakes up and sees a ton of insulin the the blood stream, but also hear's the cells bitching and moaning about needing glucose.  Because the liver can't see glucose, it just assumes you are low and says "It's time for GLUCONEOGENESIS!!!!!" and begins converting fat to glucose. Except you already have glucose!  And your glucose goes up even more.  And that's when the shit hits the fan.  Because the beta cells living in Mr. Pancreas?  They start to commit seppuku when your glucose gets over 140mg/dl.  Why?  It's complicated, but the higher your glucose, and the longer you stay there, the higher chance each one takes out their pancreatic swords and ends their lives. Forever.  Beta cells don't come back.  Once they dead, they dead. Thankfully there are ways to improve insulin resistance, unfortunately you know what increases insulin resistance?  Exposure to insulin.  Isn't that fucking awesome? What causes insulin resistance?  Well a lot of things.  Mutations in your insulin receptors (the keys on the doors in your cells), changes to your LMNA gene, too much iron, lots of things.  Some that we don't even understand. Being fat also increases your risk.  Eating too many carbs, and flooding your blood stream with constant insulin will do it too (this is how fats get it). But some of us just have weird locks on our doors, and crappy genes. On the tech front, that's what I do for a living.  We have a working prototype.  It primarily is meant to help kids and their parents better understand how their choices effect their body (telling kids to count carbs is nonsense, a five year old has trouble doing that), and parents aren't so great at understanding the special needs of their children without strong aids.