Diabetes types

Why do the categories only contain type 1 and type 2. My wife has type 3c diabetes, i.e. She has no pancreas. Admittedly the care involved is more or less identical to type 1.


Hi @ngl!
Thanks for this bit of education. I’ve never heard of Type 3c! One of the admins will come along soon and answer your question. In the meantime, welcome! :hugs:


3c is when all or part of the pancreas is destroyed by injury or disease. People often think the pancreas only produces insulin. That is less than 1% of the organ’s mass. The bulk is producing and disturbing digestive enzymes.

A common cause of 3c is severe pancreatitis where these enzymes actually digest part or all of the organ. The endocrine functions are scattered throughout the pancreas. If enough of these are destroyed gluco-regulation is impaired or nonexistent. All 5 cell types, not just Insulin secreting Beta cells.

Depending on how extensive the damage 3c patients can require insulin MDI and take oral digestive enzymes supplements with each meal. They are also prone to hypoglycemia because of the loss of glucagon secreting Alpha cells.

In my opinion type 3c diabetes mellitus is more serious than either type 1 or 2.


That’s a good question! I remember that we founding members tinkered with categories quite a bit, trying to find a balance between specificity and number of categories and subcategories. @Chris or @Eric, what are your recollections?


Thank you CarlosLuis for explaining to people more about type 3c. We often encounter people including those in the medical profession who have not heard of it. I note your comment that type 3c is more serious. My wife had her pancreas removed completely 4 years ago and thanks to Dexcom we have been able to successfully manage it. Occasionally she has suffered from hypoglycemia but thanks to the Dexcom trend graph she has by then consumed enough carbs to quickly counteract it. She has never got to the medical emergency stage. She takes Creon with every meal to aid digestion, but that has now just become a fact of life.


Yes, that’s the same thing I recall. We just picked a few D types and categories, but did not try to get overly-specific.

I think the thought was that if we have very many, and then still miss some, it’s worse than only having a few and missing some.

We can certainly add some though!


It has become common to use the word diabetes without additional qualifiers. The word just means siphon which is the common symptom of diabetes insipidus and diabetes mellitus. DI is the lack or dysfunction of the hormone vasopressin. This causes the kidneys to pass too much water into the urine. People with DI are excessively thirsty (polydipsia) with excess, colorless, tasteless urine (polyuria) . The the modifier insipid. There are 4 types of DI.

Along with polydipsia and polyuria, those with d. mellitus (L honey) have glucose in urine when not in good management. This comes in several types.

Insulin resistant type 2 DM has a strong genetic component with 30 to >70 genetic variants causing cells to resist the action of insulin while in need of fuel (glucose)

Gestational diabetes is listed separately because it appears in pregnancy going away at child birth. But women who develop GDM are at high risk of type 2 DM.

Steroid induced DM is probably type 2 brought on by increased insulin resistance caused by corticosteroid use, ether medically or abused.

Autoimmune type 1 DM is caused by the immune system being triggered to attack and destroy the insulin secreting Beta cells of the pancreas.

LADA is not a specific type but is type 1 DM.

MODY is sometimes put under T2DM, but is its own specific type and mechanism.

Pancreatogenic type 3c DM is not autoimmune type 1 or LADA, because it has its own causes which destroys the complex functions of the pancreas. It has more complicated treatment.

There are other very rare types. For more information go to this link and click on the types for a fuller explaination.


Thanks @CarlosLuis!

@Chris, @CatLady, it seems reasonable to add the missing types that are in the list @CarlosLuis posted.


My son’s father-in-law was diagnosed with Type 1 Diabetes recently. They told him it was caused by his immunotherapy medication for his cancer treatment. He said it happens to about 1% of people taking Keytruda.

I hadn’t heard of this before.


I would like to add that I am a insulin dependent diabetic, that’s about as far as I know,
When first diagnosed (and I use this term lightly) I had a bg of 643 at my doctors office, he put me on metformin and said come back in 3 months, I asked about testing in bg myself and was told it wasn’t needed. On the way home I filled script and bought meter. Well metformin didn’t help and before long he sent me to an endocrinologist.
They tested me and I got call to come in, was told I was type one and was put on pump, that was 23 years ago, well they retired and wanted to give me to a RN, I went back to my original doctor (my PCP) and had him write RX’s for my insulin, scringes and bg test supplies.
Foward to when I had heart atttack 2013, the hospital endo came around everyday and meet with me (in was in hospital 2weeks, during w rays, cat scans etc they found out I hade cancer) anyway he became my endo. But he says I am type 2 but not insulin resistant. So I don’t know what that makes me other than a insulin dependent diabetic.
And yes he put me back on pump.

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If that happened to me, I’d be inclined to ask the endo to take me through the differential diagnosis that led to that surprising conclusion.


I have and he says let me run a full panel on you again. Then it’s never discussed again.
But I want to add I read a post (Mabey this one) on t3c, never herd of it before. After was on an omnipod site and someone was talking about it. Her sons father-in-law was diagnosed with it after pancreas damage from an illness, and talked about him having to take other meds for digestive problems, pancreas controls inzimes that aid in digestion.
Well about two years before being diagnosed with diabetes I had a tramitic injury to my pancreas, was in hospital for 3 days due to it bleeding. Don’t remember what test if any at all were done but could explained a lot. I have terrible digestive issues. Have appt on dec 1sf with endo going to bring up. Also have really good gastrointestinal dr. Going to ask her also.


You are right to consult with a gastroenterologist. Bring up your past history and if possible, have your records especially of that event sent to the doc before your appointment. It is possible you might need to see a hepatologist. This specialty deals with gallbladder, liver and pancreas.

It sounds like your endo thinks there are only two types of diabetes mellitus, 1 and 2. I could be wrong, but in any case an endo would not be the usual doctor to treat digestive issues caused by the impaired exocrine (enzyme) functions of the pancreas.

For what you wrote, I’m guessing you have some endocrine and exocrine pancreatic functions, just reduced. Unlike someone whose pancreas was removed because of cancer.

The amylase test and the lipase blood test can determine the level of these two (or many) pancreatic digestive enzymes. Good luck, and if it is determined that you need supplemental enzymes, have that doc send the records to your endo. This might educate the endo without rubbing their nose in it.