Terms are grouped by topic rather than strict alphabetical order, so related ideas sit next to each other. Where a term has its own full article, its definition here links to it.
Basic diabetes terms
Blood glucose (blood sugar). The amount of sugar circulating in your bloodstream, the number a glucose meter or CGM reads. Both diabetes and normal metabolism revolve around keeping this number in a stable range.
A1C (hemoglobin A1C). A blood test that estimates average blood glucose over the past two to three months, rather than a single-moment reading. Used to track long-term control and to help diagnose diabetes in the first place.
Fasting glucose test. A blood glucose measurement taken after at least eight hours without food, often the first test that flags a diabetes diagnosis of any type.
Insulin. The hormone that lets cells pull glucose out of the bloodstream and use it for energy. Produced by beta cells in the pancreas; also available as an injectable medication when the body can’t make enough on its own.
Insulin resistance. A state where cells respond poorly to insulin, so the pancreas has to produce more of it to keep blood sugar in range. The primary mechanism behind Type 2 diabetes; not the primary mechanism behind LADA.
Beta cells. The insulin-producing cells inside the pancreas. In LADA and Type 1 diabetes, the immune system gradually destroys these cells; in Type 2, they’re usually intact but working against insulin resistance.
Hyperglycemia / hypoglycemia. Blood sugar that’s too high (hyperglycemia) or too low (hypoglycemia). Hypoglycemia is a particular risk when starting or adjusting insulin or other glucose-lowering medication.
Autoimmune and LADA-specific terms
LADA (latent autoimmune diabetes in adults). A form of diabetes where the immune system slowly destroys insulin-producing beta cells, the same underlying process as Type 1 diabetes, but developing gradually and typically starting after age 30. See What Is LADA? for the full explanation.
Type 1.5 diabetes. An informal, non-official term some clinicians and patients use for LADA, reflecting that it sits between Type 1 and Type 2 in how it behaves.
Autoimmune disease. A condition where the immune system mistakenly attacks the body’s own healthy cells. LADA and Type 1 diabetes are both autoimmune diseases targeting the pancreas; Type 2 diabetes is not autoimmune.
Autoantibody. An antibody the immune system produces against the body’s own proteins, rather than against an outside invader like a virus. Autoantibody tests, like GAD65, are how LADA is distinguished from Type 2 in a lab.
Honeymoon phase. The period after an autoimmune diabetes diagnosis when enough beta cell function remains that blood sugar is relatively easy to manage, sometimes without insulin at all. It ends as beta cell destruction continues, not because anything was managed incorrectly.
Beta cell failure (insulin deficiency). The end state of the autoimmune process behind LADA and Type 1 diabetes: beta cells can no longer produce enough insulin to meet the body’s needs, regardless of insulin sensitivity. This is different from the insulin resistance behind Type 2 diabetes.
Tests and diagnosis
GAD65 antibodies. The autoantibody test most closely associated with LADA; positive in roughly 90% of LADA cases. See GAD65 Antibodies Explained.
IA-2, ZnT8, ICA, and IAA. Additional autoantibody tests sometimes used alongside GAD65, particularly when GAD65 is negative but LADA is still suspected. See Beyond GAD65 for what each one measures.
C-peptide. A blood test that measures how much insulin your pancreas is still producing on its own, distinct from antibody tests, which only confirm that an autoimmune process is happening, not how far it’s progressed. Falling C-peptide over time is how doctors track LADA’s progression toward insulin dependence.
Immunology of Diabetes Society (IDS) criteria. The most widely used clinical definition of LADA: adult onset, at least one positive islet autoantibody, and no insulin requirement for at least six months after diagnosis. A single positive antibody, most often GAD65, is sufficient to meet this definition.
This page is educational, not medical advice. If a term here relates to your own results or diagnosis, bring the specific numbers to your doctor rather than interpreting them from a definition alone.