by Ahmed
(Aden)
QUESTION: Why does diabetic ketoacidosis usually occur in type 1 diabetes but not type 2 diabetes? Can people with type 2 diabetes also develop DKA?
DKA is much more common in type 1 diabetes, but people with type 2 diabetes can develop it too. Type 1 diabetes usually causes an almost complete lack of insulin, allowing rapid fat breakdown and ketone production. Most people with type 2 diabetes retain enough insulin to suppress ketones even when glucose is very high, so hyperosmolar hyperglycemic state, or HHS, is more typical. Severe illness, missed insulin, advanced insulin deficiency, or SGLT2 medicines can nevertheless cause DKA in type 2 diabetes.
Answer by Dr. Albana Greca, MD, MMedSc
Hi Ahmed,
The statement “type 1 has ketoacidosis and type 2 does not” is incorrect. The main difference is how much effective insulin remains.
DKA is a life-threatening emergency caused by insufficient insulin together with increased counter-regulatory hormones such as glucagon, adrenaline, cortisol, and growth hormone. The body cannot use glucose normally and begins breaking down fat. The liver converts fatty acids into ketones, which accumulate and make the blood acidic.
DKA requires diabetes or hyperglycemia, elevated ketones, and metabolic acidosis. It can occasionally occur below 200 mg/dL. Review dangerous glucose levels and ketones.
In type 1 diabetes, autoimmune destruction of pancreatic beta cells causes severe or absolute insulin deficiency. Without enough basal insulin:
This process can progress quickly after insulin is missed, a pump stops delivering insulin, or illness increases insulin needs. That is why basal insulin treatment should not be stopped during illness or fasting unless the diabetes team gives different instructions.
Type 2 diabetes usually begins with insulin resistance while the pancreas continues producing insulin. That insulin may be insufficient to control glucose, but often it is still enough to suppress extensive fat breakdown and ketone production.
A person with type 2 diabetes may therefore develop extreme hyperglycemia and dehydration without substantial ketoacidosis. This is hyperosmolar hyperglycemic state, or HHS.
Yes. DKA can occur in type 2 diabetes when effective insulin becomes severely deficient. Common triggers include:
Some people labelled as having type 2 diabetes have autoimmune or ketosis-prone diabetes. The diabetes type should be reviewed after recovery when uncertain.
Euglycemic DKA means ketones and acidosis are present even though glucose is below 200 mg/dL or only moderately elevated. It can occur with SGLT2 inhibitors, pregnancy, reduced food intake, alcohol use, liver disease, or after some insulin has been taken.
People taking empagliflozin, dapagliflozin, canagliflozin, or a similar medicine should not assume they are safe because the meter is not extremely high. Review all treatment risks in our diabetes medicine safety guide.
A person can have severe hyperglycemia, dehydration, ketones, and acidosis together. Mixed DKA/HHS requires hospital treatment.
Follow the individual's sick-day plan. Ketones are commonly checked during illness, after missed insulin, when a pump may have failed, when DKA symptoms appear, or when glucose remains above about 200–250 mg/dL. Blood beta-hydroxybutyrate testing detects the main DKA ketone more directly than urine strips.
Keep insulin doses, glucose, ketones, illness symptoms, and corrections in a blood sugar log. Do not exercise when ketones are moderate or high because activity may worsen ketosis.
Warning signs include excessive thirst, frequent urination, dry mouth, weakness, nausea, vomiting, abdominal pain, fruity-smelling breath, and deep or rapid breathing. Drowsiness, confusion, fainting, or inability to keep fluids down indicate a medical emergency.
Read what to do with glucose between 250 and 400 mg/dL and blood sugar over 400 mg/dL, but remember that symptoms and ketones matter more than one number.
Seek emergency care for repeated vomiting, abdominal pain, deep or difficult breathing, fruity breath, marked dehydration, confusion, fainting, or moderate or high ketones that do not improve after the prescribed correction plan. Do not stop basal insulin. People using SGLT2 inhibitors need urgent assessment for these symptoms even when glucose is below 200 mg/dL.
Type 1 diabetes carries the greatest DKA risk because insulin deficiency is usually absolute. Type 2 diabetes usually retains enough insulin to limit ketone formation, but that protection can be lost. Never rule out DKA solely because a person has type 2 diabetes or because glucose is not extremely high.
Educational safety note: This answer is for general diabetes education only. It does not replace an individualized sick-day or emergency plan. Do not stop insulin, take extra correction insulin, exercise with ketones, or change an SGLT2 inhibitor without instructions from the diabetes healthcare team.
Last reviewed: July 2026.
Click here to post comments or follow up
Ask the Doctor now? Simply click here to return to Complications from diabetes.