NSG 550 Exams 1–3 – Wilkes Diagnostic
Reasoning Examination 2026–2027 |
Comprehensive 150 -Question Practice Test
with Answers & Rationales| Free Pdf Access.
Foundational Reasoning and Renal / Urologic Diagnostics
Question 1
A 72-year-old male with diabetes presents with three days of vomiting and poor oral
intake. His labs show BUN 48 mg/dL and creatinine 1.8 mg/dL, with a BUN-to-creatinine
ratio of 30:1. What is the most likely diagnosis?
A) Intrinsic renal failure from diabetic nephropathy
B) Postrenal obstruction from prostate enlargement
C) Prerenal azotemia from volume depletion
D) Acute interstitial nephritis from medications
Correct Answer: C) Prerenal azotemia from volume depletion
A normal BUN-to-creatinine ratio is about 10:1 to 20:1. When this ratio rises above 20:1, it
usually means the kidneys are holding onto urea because there is not enough fluid flowing
through them. This patient has been vomiting and not drinking enough, which leads to
dehydration and reduced blood flow to the kidneys. This is called prerenal azotemia.
Intrinsic kidney damage would raise both BUN and creatinine more evenly, and
obstruction would usually cause pain or inability to urinate. Diabetic nephropathy is a
chronic condition and would not cause this sudden change by itself.
,Question 2
A 67-year-old man has a PSA of 5.2 ng/mL, up from 3.0 ng/mL one year ago. His rectal
exam is normal. What is the best interpretation?
A) This definitively confirms prostate cancer
B) This is in the gray zone and needs further evaluation
C) This is normal for his age and needs no follow-up
D) This is just due to benign enlargement and can be ignored
Correct Answer: B) This is in the gray zone and needs further evaluation
A PSA between 4 and 10 is called the gray zone because it is not high enough to clearly
point to cancer, but it is also not low enough to be considered normal. Many things can
raise PSA, including infection, inflammation, and benign growth of the prostate. What
makes this case more concerning is that the PSA has risen significantly over the past year.
This rising trend, called PSA velocity, means the patient should have more testing, such as
a repeat PSA with percent free PSA or a referral to a urologist. It would be wrong to
assume cancer is present or to dismiss it as harmless without further investigation.
Question 3
A new urine test for infection gives the same result every time it is tested on the same
sample. However, many patients with confirmed infections test negative. How should
this test be described?
A) Highly sensitive and specific
B) Accurate but not precise
C) Precise but not accurate
D) Highly sensitive but not specific
Correct Answer: C) Precise but not accurate
,Precision means the test gives consistent results each time it is used. This test does that, so
it is precise. However, accuracy means the test correctly identifies who has the disease and
who does not. Because this test often gives negative results in patients who actually have
an infection, it is missing many true cases. These are called false negatives, and they mean
the test has poor sensitivity. A test that misses many sick patients cannot be considered
accurate, no matter how consistent its results appear. For a test to be clinically useful, it
needs both precision and accuracy.
Exam 2 Content: Cardiopulmonary, Gastrointestinal, and Endocrine Systems
Question 4
A 45-year-old man arrives with chest pain radiating to his jaw and arm. He is sweating
and nauseated. His ECG shows ST elevation in leads II, III, and aVF. What is the most
likely diagnosis?
A) Anteroseptal myocardial infarction
B) Inferior wall myocardial infarction
C) Unstable angina
D) Acute pericarditis
Correct Answer: B) Inferior wall myocardial infarction
The ECG leads II, III, and aVF look at the bottom wall of the heart, which is called the
inferior wall. When ST segments are elevated in these leads, it means the inferior wall is
not getting enough blood, usually because the right coronary artery is blocked. This is an
inferior wall MI. An anteroseptal MI would show changes in leads V1 to V4, which look at
the front and middle of the heart. Unstable angina does not cause ST elevation, and
pericarditis usually causes widespread ST elevation that curves upward like a smile, not
the straight elevation seen in a heart attack.
, Question 5
A 60-year-old woman with recent knee surgery has sudden shortness of breath and
chest pain. You estimate her risk of pulmonary embolism is about 40%. The D-dimer test
has 95% sensitivity and 50% specificity. What should you do next?
A) Order a D-dimer
B) Order a CT pulmonary angiogram
C) Order a chest X-ray
D) Order a ventilation-perfusion scan
Correct Answer: B) Order a CT pulmonary angiogram
A D-dimer test is most useful when the pretest probability of pulmonary embolism is low.
In that situation, a negative D-dimer can safely rule out the disease because the test is
very sensitive. However, when the pretest probability is moderate or high, the D-dimer’s
low specificity becomes a problem. With only 50% specificity, the test will be falsely
positive in half of all people without a clot. This means a positive result would not give you
useful information, and you would still need to do more testing. In this case, the patient’s
risk is high enough that you should skip the D-dimer and go straight to a CT pulmonary
angiogram, which is the definitive test for diagnosing a pulmonary embolism.
Question 6
A 38-year-old woman reports fatigue, weight gain, and feeling cold for the past three
months. Her TSH is 8.5 mIU/L and her free T4 is low. What is the diagnosis?
A) Hyperthyroidism
B) Primary hypothyroidism
Reasoning Examination 2026–2027 |
Comprehensive 150 -Question Practice Test
with Answers & Rationales| Free Pdf Access.
Foundational Reasoning and Renal / Urologic Diagnostics
Question 1
A 72-year-old male with diabetes presents with three days of vomiting and poor oral
intake. His labs show BUN 48 mg/dL and creatinine 1.8 mg/dL, with a BUN-to-creatinine
ratio of 30:1. What is the most likely diagnosis?
A) Intrinsic renal failure from diabetic nephropathy
B) Postrenal obstruction from prostate enlargement
C) Prerenal azotemia from volume depletion
D) Acute interstitial nephritis from medications
Correct Answer: C) Prerenal azotemia from volume depletion
A normal BUN-to-creatinine ratio is about 10:1 to 20:1. When this ratio rises above 20:1, it
usually means the kidneys are holding onto urea because there is not enough fluid flowing
through them. This patient has been vomiting and not drinking enough, which leads to
dehydration and reduced blood flow to the kidneys. This is called prerenal azotemia.
Intrinsic kidney damage would raise both BUN and creatinine more evenly, and
obstruction would usually cause pain or inability to urinate. Diabetic nephropathy is a
chronic condition and would not cause this sudden change by itself.
,Question 2
A 67-year-old man has a PSA of 5.2 ng/mL, up from 3.0 ng/mL one year ago. His rectal
exam is normal. What is the best interpretation?
A) This definitively confirms prostate cancer
B) This is in the gray zone and needs further evaluation
C) This is normal for his age and needs no follow-up
D) This is just due to benign enlargement and can be ignored
Correct Answer: B) This is in the gray zone and needs further evaluation
A PSA between 4 and 10 is called the gray zone because it is not high enough to clearly
point to cancer, but it is also not low enough to be considered normal. Many things can
raise PSA, including infection, inflammation, and benign growth of the prostate. What
makes this case more concerning is that the PSA has risen significantly over the past year.
This rising trend, called PSA velocity, means the patient should have more testing, such as
a repeat PSA with percent free PSA or a referral to a urologist. It would be wrong to
assume cancer is present or to dismiss it as harmless without further investigation.
Question 3
A new urine test for infection gives the same result every time it is tested on the same
sample. However, many patients with confirmed infections test negative. How should
this test be described?
A) Highly sensitive and specific
B) Accurate but not precise
C) Precise but not accurate
D) Highly sensitive but not specific
Correct Answer: C) Precise but not accurate
,Precision means the test gives consistent results each time it is used. This test does that, so
it is precise. However, accuracy means the test correctly identifies who has the disease and
who does not. Because this test often gives negative results in patients who actually have
an infection, it is missing many true cases. These are called false negatives, and they mean
the test has poor sensitivity. A test that misses many sick patients cannot be considered
accurate, no matter how consistent its results appear. For a test to be clinically useful, it
needs both precision and accuracy.
Exam 2 Content: Cardiopulmonary, Gastrointestinal, and Endocrine Systems
Question 4
A 45-year-old man arrives with chest pain radiating to his jaw and arm. He is sweating
and nauseated. His ECG shows ST elevation in leads II, III, and aVF. What is the most
likely diagnosis?
A) Anteroseptal myocardial infarction
B) Inferior wall myocardial infarction
C) Unstable angina
D) Acute pericarditis
Correct Answer: B) Inferior wall myocardial infarction
The ECG leads II, III, and aVF look at the bottom wall of the heart, which is called the
inferior wall. When ST segments are elevated in these leads, it means the inferior wall is
not getting enough blood, usually because the right coronary artery is blocked. This is an
inferior wall MI. An anteroseptal MI would show changes in leads V1 to V4, which look at
the front and middle of the heart. Unstable angina does not cause ST elevation, and
pericarditis usually causes widespread ST elevation that curves upward like a smile, not
the straight elevation seen in a heart attack.
, Question 5
A 60-year-old woman with recent knee surgery has sudden shortness of breath and
chest pain. You estimate her risk of pulmonary embolism is about 40%. The D-dimer test
has 95% sensitivity and 50% specificity. What should you do next?
A) Order a D-dimer
B) Order a CT pulmonary angiogram
C) Order a chest X-ray
D) Order a ventilation-perfusion scan
Correct Answer: B) Order a CT pulmonary angiogram
A D-dimer test is most useful when the pretest probability of pulmonary embolism is low.
In that situation, a negative D-dimer can safely rule out the disease because the test is
very sensitive. However, when the pretest probability is moderate or high, the D-dimer’s
low specificity becomes a problem. With only 50% specificity, the test will be falsely
positive in half of all people without a clot. This means a positive result would not give you
useful information, and you would still need to do more testing. In this case, the patient’s
risk is high enough that you should skip the D-dimer and go straight to a CT pulmonary
angiogram, which is the definitive test for diagnosing a pulmonary embolism.
Question 6
A 38-year-old woman reports fatigue, weight gain, and feeling cold for the past three
months. Her TSH is 8.5 mIU/L and her free T4 is low. What is the diagnosis?
A) Hyperthyroidism
B) Primary hypothyroidism
