NSG 3280 Walden University Nursing Diabetes Mellitus
Practice Exam 2026 | 50 NCLEX-Style Questions with
Detailed Rationales
(Diabetes Mellitus)
Question 1 A 45-year-old female patient with newly diagnosed type 2 diabetes
mellitus asks the nurse about the primary cause of her condition. Which statement
by the nurse best explains the pathophysiology?
A. “Your body is producing too much insulin, which causes your blood sugar to
drop.”
B. “Your pancreas is not producing enough insulin, and your cells are resistant to
the insulin that is present.”
C. “Your liver is releasing too much glucose into the bloodstream at night.”
D. “Your kidneys are unable to filter glucose properly, leading to high blood
sugar.”
Correct Answer✅: B
Rationale: The correct answer is B because type 2 diabetes mellitus is primarily
characterized by insulin resistance in peripheral tissues combined with progressive
beta-cell dysfunction in the pancreas, resulting in relative insulin deficiency..
,Question 2 The nurse is teaching a 52-year-old male patient newly prescribed
metformin for type 2 diabetes. Which instruction is most important for the patient
to follow to prevent a common adverse effect?
A. Take the medication with meals.
B. Increase fluid intake to at least 3 liters daily.
C. Monitor for signs of lactic acidosis, such as muscle pain.
D. Expect increased appetite as a side effect.
Correct Answer✅: A
Rationale: Taking metformin with meals (option A) is the most important
instruction because it significantly reduces gastrointestinal upset, the most
common adverse effect..
Question 3 A patient with type 1 diabetes mellitus reports checking blood glucose
before meals. The nurse knows the target preprandial blood glucose range
recommended by current guidelines is:
A. 70–130 mg/dL
B. 80–140 mg/dL
C. 90–150 mg/dL
D. 100–160 mg/dL
Correct Answer✅: A
Rationale: The American Diabetes Association recommends a preprandial plasma
glucose target of 80–130 mg/dL (often simplified to 70–130 mg/dL in practice
questions) for most nonpregnant adults with diabetes to balance glycemic control
,and hypoglycemia risk. This range reflects evidence-based practice balancing
microvascular complication prevention with safety. The other options represent
slightly higher or broader ranges that may be appropriate for specific populations
(e.g., older adults) but are not the standard target for a typical adult patient.
Question 4 During a home visit, the nurse assesses a 68-year-old patient with type
2 diabetes who reports tingling and numbness in both feet. Which finding should
the nurse prioritize documenting?
A. Presence of foot ulcers
B. Decreased pedal pulses
C. Monofilament testing results
D. Skin temperature and color
Correct Answer✅: C
Rationale: Monofilament testing (option C) is the priority because it specifically
evaluates protective sensation and is a key component of annual diabetic foot
screening to identify loss of protective sensation, which greatly increases ulcer
risk.
Question 5 A 55-year-old female patient with diabetes is admitted with a blood
glucose level of 428 mg/dL and reports nausea and vomiting. Which laboratory
value should the nurse anticipate monitoring closely to assess for diabetic
ketoacidosis?
A. Serum potassium
B. Arterial blood pH
C. Hemoglobin A1c
, D. Serum creatinine
Correct Answer✅: B
Rationale: Arterial blood pH (option B) is critical to monitor because diabetic
ketoacidosis is defined by metabolic acidosis (pH <7.3) due to ketone production..
Question 6 The nurse is prioritizing care for four patients on a medical-surgical
unit. Which patient requires the most immediate intervention?
A. A 72-year-old with type 2 diabetes and a blood glucose of 285 mg/dL who is
asymptomatic.
B. A 19-year-old with type 1 diabetes who is confused and has a blood glucose of
62 mg/dL.
C. A 45-year-old with type 2 diabetes complaining of blurred vision and a blood
glucose of 320 mg/dL.
D. A 60-year-old with type 2 diabetes who has a foot ulcer with moderate drainage.
Correct Answer✅: B
Rationale: The 19-year-old with hypoglycemia (blood glucose 62 mg/dL) and
altered mental status (option B) represents the highest priority due to the risk of
rapid deterioration, seizures, or coma. Hypoglycemia requires immediate treatment
with fast-acting carbohydrates or glucagon. The other patients have hyperglycemia
or chronic complications that, while important, do not pose the same immediate
life-threatening risk. This reflects the nursing priority of addressing acute
physiologic instability first.
Question 7 A patient with type 2 diabetes is started on insulin glargine. The nurse
should teach the patient that this medication is best described as:
Practice Exam 2026 | 50 NCLEX-Style Questions with
Detailed Rationales
(Diabetes Mellitus)
Question 1 A 45-year-old female patient with newly diagnosed type 2 diabetes
mellitus asks the nurse about the primary cause of her condition. Which statement
by the nurse best explains the pathophysiology?
A. “Your body is producing too much insulin, which causes your blood sugar to
drop.”
B. “Your pancreas is not producing enough insulin, and your cells are resistant to
the insulin that is present.”
C. “Your liver is releasing too much glucose into the bloodstream at night.”
D. “Your kidneys are unable to filter glucose properly, leading to high blood
sugar.”
Correct Answer✅: B
Rationale: The correct answer is B because type 2 diabetes mellitus is primarily
characterized by insulin resistance in peripheral tissues combined with progressive
beta-cell dysfunction in the pancreas, resulting in relative insulin deficiency..
,Question 2 The nurse is teaching a 52-year-old male patient newly prescribed
metformin for type 2 diabetes. Which instruction is most important for the patient
to follow to prevent a common adverse effect?
A. Take the medication with meals.
B. Increase fluid intake to at least 3 liters daily.
C. Monitor for signs of lactic acidosis, such as muscle pain.
D. Expect increased appetite as a side effect.
Correct Answer✅: A
Rationale: Taking metformin with meals (option A) is the most important
instruction because it significantly reduces gastrointestinal upset, the most
common adverse effect..
Question 3 A patient with type 1 diabetes mellitus reports checking blood glucose
before meals. The nurse knows the target preprandial blood glucose range
recommended by current guidelines is:
A. 70–130 mg/dL
B. 80–140 mg/dL
C. 90–150 mg/dL
D. 100–160 mg/dL
Correct Answer✅: A
Rationale: The American Diabetes Association recommends a preprandial plasma
glucose target of 80–130 mg/dL (often simplified to 70–130 mg/dL in practice
questions) for most nonpregnant adults with diabetes to balance glycemic control
,and hypoglycemia risk. This range reflects evidence-based practice balancing
microvascular complication prevention with safety. The other options represent
slightly higher or broader ranges that may be appropriate for specific populations
(e.g., older adults) but are not the standard target for a typical adult patient.
Question 4 During a home visit, the nurse assesses a 68-year-old patient with type
2 diabetes who reports tingling and numbness in both feet. Which finding should
the nurse prioritize documenting?
A. Presence of foot ulcers
B. Decreased pedal pulses
C. Monofilament testing results
D. Skin temperature and color
Correct Answer✅: C
Rationale: Monofilament testing (option C) is the priority because it specifically
evaluates protective sensation and is a key component of annual diabetic foot
screening to identify loss of protective sensation, which greatly increases ulcer
risk.
Question 5 A 55-year-old female patient with diabetes is admitted with a blood
glucose level of 428 mg/dL and reports nausea and vomiting. Which laboratory
value should the nurse anticipate monitoring closely to assess for diabetic
ketoacidosis?
A. Serum potassium
B. Arterial blood pH
C. Hemoglobin A1c
, D. Serum creatinine
Correct Answer✅: B
Rationale: Arterial blood pH (option B) is critical to monitor because diabetic
ketoacidosis is defined by metabolic acidosis (pH <7.3) due to ketone production..
Question 6 The nurse is prioritizing care for four patients on a medical-surgical
unit. Which patient requires the most immediate intervention?
A. A 72-year-old with type 2 diabetes and a blood glucose of 285 mg/dL who is
asymptomatic.
B. A 19-year-old with type 1 diabetes who is confused and has a blood glucose of
62 mg/dL.
C. A 45-year-old with type 2 diabetes complaining of blurred vision and a blood
glucose of 320 mg/dL.
D. A 60-year-old with type 2 diabetes who has a foot ulcer with moderate drainage.
Correct Answer✅: B
Rationale: The 19-year-old with hypoglycemia (blood glucose 62 mg/dL) and
altered mental status (option B) represents the highest priority due to the risk of
rapid deterioration, seizures, or coma. Hypoglycemia requires immediate treatment
with fast-acting carbohydrates or glucagon. The other patients have hyperglycemia
or chronic complications that, while important, do not pose the same immediate
life-threatening risk. This reflects the nursing priority of addressing acute
physiologic instability first.
Question 7 A patient with type 2 diabetes is started on insulin glargine. The nurse
should teach the patient that this medication is best described as:
