@JonDeutsch get ready for a bunch of verbosity, but as you so kindly asked.
I am a stickler for using the correct terminology. This puts be at odds with the NIH, WHO and CDC because they use the word, diabetes which derives from the Greek for siphon or go through. There are some seven types of diseases that have excessive urine as a symptom.
Diabetes mellitus is marked by sweet excessive urination and thirst. Diabetes insipidus the urine is nearly pure water, insipid. (seen word origins posted at the end)
There are four types of diabetes insipidus that cause extreme urination, but do not affect blood glucose levels. It is fairly rare, but should not be forgotten. A lot of doctors don’t even consider DI when a patient complains of thirst and urination. They assume diabetes mellitus.
There are 3 main types of diabetes mellitus, each with sub types. Type 1 DM is autoimmune that requires a genetic component that gets triggered by a viral infection. The immune system targets the insulin producing Beta cells. It often occurs in early childhood and early teens to young adults. A sub type is Latent Autoimmune Diabetes in Adults (LADA). It tends to occur in middle age, is slow to develop and is often misdiagnosed as Type 2 DM.
Often lumped up with type 1 DM is Neonatal diabetes. It is caused by one gene. It sometimes resolves by 6 months, but for about half born with it, it is for life. They will always be insulin dependent.
Type 2 DM is the most common and in the past appeared in middle age. There is a group or set of genes that cause cellular insulin receptors to resist the attachment of insulin. This is a different modality than type 1 DM. T2DMs in the early stages secrete lots of insulin, causing intermittant hypoglycemia and hyperglycemia with a build up of fatty tissue. Over time the overworked Beta cells tire, causing a progression of the disease.
Early on T2DMs can often achieve near normal BG levels and increased insulin sensitivity through diet and daily exercise. If it progresses, the patient will need drug therapy in addition, and finally supplemental insulin.
Maturity-onset diabetes of the young (MODY) is an outlier. It affect young people, but is not autoimmune. A change in a single gene in a group of 14 genes cause a deficiency of insulin secretion. MODY is not really type 1 or 2.
Type 3cDM is when the exocrine portion of the pancreas is injured by disease such as cancer or pancreatitis. The pancreas does a whole lot more than secrete insulin. There are 6 endocrine hormones from various islets of Langerhans and 2 or more exocrine enzymes that aid digestion. Damage to the exocrine area of the organ can also damage some of the islets causing blood glucose control issues. T3cDM can require complete insulin replacement or perhaps none at all, as the remaining Beta cells are secreting enough. Each T3cDM is a unique patient.
Well we all are, but more so for the 3c people.
I really don’t know how to define diabetes without specifying just what type the diabetes is.
ORIGIN
mid 16th century: via Latin from Greek, literally ‘siphon’, from diabainein ‘go through’; mellitus is from Latin mellitus ‘sweet’.
ORIGIN
late 19th century: from diabetes + Latin insipidus ‘insipid’.