An A1C of 6.5% or higher is diagnostic of diabetes.
Before you read
Test yourself first: 4 questions
Question 1 of 4
A client involved in a structure fire is suspected of carbon monoxide poisoning. The pulse oximeter reads 98%, yet the client is confused and reports a headache. What is the nurse's best interpretation?
Answer: B. Carbon monoxide binds hemoglobin with far greater affinity than oxygen, forming carboxyhemoglobin. A standard pulse oximeter cannot distinguish carboxyhemoglobin from oxyhemoglobin, so it may read falsely normal or high despite tissue hypoxia. The treatment is 100% oxygen by nonrebreather mask. The reading should not be trusted as evidence of adequate oxygenation.
Question 2 of 4
A nurse is reviewing a client's labs and finds a hemoglobin A1c of 9.5%. How does the nurse interpret this result?
Answer: B. Hemoglobin A1c reflects average blood glucose over the past 2 to 3 months. The general target for many adults with diabetes is below 7%, so an A1c of 9.5% indicates poor long-term glycemic control and increased risk of complications. It does not measure a single-day glucose value.
Question 3 of 4
A client's hemoglobin is 6.5 g/dL. Which assessment finding does the nurse anticipate?
Answer: A. Hemoglobin of 6.5 g/dL is critically low (normal roughly 12-17). Severe anemia reduces oxygen-carrying capacity, producing tachycardia, dyspnea, pallor, and fatigue as the body compensates.
Question 4 of 4
A client receiving chemotherapy has a hemoglobin of 7.8 g/dL and reports fatigue and shortness of breath on exertion. These findings are most consistent with which complication of myelosuppression?
Answer: A. Chemotherapy-induced bone marrow suppression lowers red blood cell production, causing anemia. Fatigue, pallor, and dyspnea on exertion are classic anemia symptoms with a low hemoglobin. Neutropenia presents with infection risk, thrombocytopenia with bleeding, and tumor lysis with electrolyte disturbances.
Keep the streak going with more questions like these, each with a full rationale.
What is hemoglobin a1c?
Unlike a single glucose reading, it is not affected by recent meals, making it the standard for diagnosing diabetes and evaluating long-term glycemic control. A higher A1C indicates poorer overall control.
Key points to remember
- An A1C of 6.5% or higher is diagnostic of diabetes.
- An A1C of 5.7 to 6.4% indicates prediabetes, and below 5.7% is normal.
- A common target for many people with diabetes is an A1C below 7%.
- A1C reflects the average glucose over roughly 3 months and does not require fasting.
- A1C is not used to manage acute hypoglycemia or hyperglycemia in the moment.
- Conditions affecting red cell lifespan, such as anemia, can skew A1C results.
Nursing priorities
- Review the A1C with the patient's home glucose logs to assess overall control.
- Reinforce diet, activity, and medication adherence when the A1C is elevated.
- Coordinate diabetes education and follow-up based on the result.
- Use point-of-care glucose, not A1C, to guide treatment of an acute glucose emergency.
- Assess for complications of chronic hyperglycemia in patients with persistently high A1C.
Labs & values
Patient teaching
- Continue daily glucose monitoring; A1C shows the long-term average, not today's level.
- Adhere to diet, exercise, and medication to lower A1C and reduce risk of long-term complications.
Red flags: report now
- A markedly elevated A1C with symptoms of hyperglycemia warrants prompt provider follow-up for regimen change.
- Never treat acute high or low blood sugar based on A1C; use a current fingerstick glucose.
- Recurrent hypoglycemia despite a high A1C needs reporting, as it suggests unstable control.
References
Clinical references for this topic
