Interpretation of clinical laboratory tests – blood chemistry and hematology MCQs With Answer

Understanding interpretation of clinical laboratory tests in blood chemistry and hematology is essential for B.Pharm students. This concise guide focuses on interpreting CBC parameters, red cell indices, white cell differentials, platelet counts, coagulation tests (PT/INR, aPTT), electrolytes, renal and liver function tests, glucose and lipid profiles, blood gases, and key biomarkers. Emphasis is placed on reference ranges, sample handling, pathophysiologic correlations, and clinical decision‑making. Mastery of test limitations, preanalytical variables, and pattern recognition will improve pharmacotherapeutic recommendations and patient safety. Practical scenarios bridge theory and practice to sharpen analytical skills. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What does an elevated mean corpuscular volume (MCV) most likely indicate?

  • Iron deficiency anemia
  • Macrocytic anemia
  • Microcytic anemia
  • Hemolytic anemia

Correct Answer: Macrocytic anemia

Q2. Which parameter on a CBC best reflects oxygen-carrying capacity of blood?

  • White blood cell count
  • Platelet count
  • Hemoglobin concentration
  • Mean platelet volume

Correct Answer: Hemoglobin concentration

Q3. A high reticulocyte count most specifically suggests which process?

  • Bone marrow suppression
  • Active hemolysis or recent blood loss with marrow response
  • Chronic iron deficiency without treatment
  • Platelet destruction

Correct Answer: Active hemolysis or recent blood loss with marrow response

Q4. Which test is most sensitive for detecting early renal dysfunction?

  • Serum sodium
  • Serum creatinine
  • Blood urea nitrogen (BUN)
  • Estimated glomerular filtration rate (eGFR)

Correct Answer: Estimated glomerular filtration rate (eGFR)

Q5. An increased AST to ALT ratio (>2) is classically associated with which condition?

  • Acute viral hepatitis
  • Alcoholic liver disease
  • Cholestasis
  • Nonalcoholic fatty liver disease

Correct Answer: Alcoholic liver disease

Q6. Which electrolyte abnormality is most commonly associated with peaked T waves and wide QRS on ECG?

  • Hypokalemia
  • Hyperkalemia
  • Hypernatremia
  • Hypocalcemia

Correct Answer: Hyperkalemia

Q7. A prolonged prothrombin time (PT) with normal activated partial thromboplastin time (aPTT) suggests abnormality in which pathway?

  • Intrinsic coagulation pathway
  • Extrinsic coagulation pathway
  • Common coagulation pathway only
  • Platelet function

Correct Answer: Extrinsic coagulation pathway

Q8. Which blood gas finding indicates uncompensated metabolic acidosis?

  • pH 7.50, HCO3- 30 mmol/L
  • pH 7.20, HCO3- 12 mmol/L
  • pH 7.40, PaCO2 40 mmHg
  • pH 7.35, HCO3- 26 mmol/L

Correct Answer: pH 7.20, HCO3- 12 mmol/L

Q9. Elevated serum ammonia most directly correlates with dysfunction of which organ?

  • Kidney
  • Lung
  • Liver
  • Pancreas

Correct Answer: Liver

Q10. In iron deficiency anemia, what is the typical pattern of RDW and MCV?

  • Normal RDW, high MCV
  • High RDW, low MCV
  • Low RDW, high MCV
  • High RDW, high MCV

Correct Answer: High RDW, low MCV

Q11. Which lipid parameter is best used to estimate cardiovascular risk when measured fasting?

  • Total cholesterol alone
  • Triglycerides alone
  • Low-density lipoprotein cholesterol (LDL-C)
  • High-density lipoprotein cholesterol (HDL-C)

Correct Answer: Low-density lipoprotein cholesterol (LDL-C)

Q12. A markedly elevated alkaline phosphatase with normal GGT suggests which source?

  • Hepatobiliary origin
  • Bone origin
  • Renal origin
  • Cardiac origin

Correct Answer: Bone origin

Q13. Which HbA1c value roughly corresponds to a mean plasma glucose of 154 mg/dL? (Use common approximation)

  • 4.5%
  • 6.5%
  • 7.0%
  • 8.0%

Correct Answer: 7.0%

Q14. Which white blood cell predominance is most characteristic of acute bacterial infection?

  • Lymphocytosis
  • Eosinophilia
  • Neutrophilia with left shift
  • Monocytopenia

Correct Answer: Neutrophilia with left shift

Q15. A low platelet count with prolonged bleeding time most likely indicates which condition?

  • Thrombocytopenia
  • Polycythemia vera
  • Hemolytic anemia
  • Leukopenia

Correct Answer: Thrombocytopenia

Q16. In cholestatic liver injury, which pattern of enzymes is typical?

  • High AST and ALT, normal ALP
  • Predominant elevation of alkaline phosphatase and bilirubin
  • Isolated elevated GGT without ALP change
  • Low AST, low ALT, low bilirubin

Correct Answer: Predominant elevation of alkaline phosphatase and bilirubin

Q17. An increased anion gap metabolic acidosis is most commonly caused by which process?

  • Diarrhea causing bicarbonate loss
  • Lactic acidosis or ketoacidosis
  • Hyperaldosteronism
  • Excessive intake of bicarbonate

Correct Answer: Lactic acidosis or ketoacidosis

Q18. Which marker is most specific for myocardial cell injury?

  • Creatine kinase-MB (CK-MB)
  • Troponin I or T
  • AST
  • LDH

Correct Answer: Troponin I or T

Q19. Hemolysis in vitro can artificially alter which laboratory values?

  • Falsely low potassium and AST
  • Falsely high potassium and LDH
  • Falsely low bilirubin and hemoglobin
  • No effect on chemistry tests

Correct Answer: Falsely high potassium and LDH

Q20. A low serum albumin with normal transaminases and elevated alkaline phosphatase suggests which scenario?

  • Acute hepatocellular injury
  • Chronic liver disease with cholestasis or malnutrition
  • Acute myocardial infarction
  • Acute pancreatitis

Correct Answer: Chronic liver disease with cholestasis or malnutrition

Q21. Which test is most appropriate to monitor unfractionated heparin therapy?

  • Prothrombin time (PT)
  • Activated partial thromboplastin time (aPTT)
  • Platelet count
  • D-dimer

Correct Answer: Activated partial thromboplastin time (aPTT)

Q22. In which condition would you expect an isolated elevation of indirect (unconjugated) bilirubin?

  • Hemolytic anemia
  • Obstructive cholestasis
  • Hepatocellular necrosis
  • Gilbert syndrome

Correct Answer: Hemolytic anemia

Q23. Which lab pattern is typical of dehydration affecting basic chemistries?

  • Hyponatremia with low BUN
  • Elevated BUN:creatinine ratio
  • Low hematocrit and low hemoglobin
  • Low serum osmolality

Correct Answer: Elevated BUN:creatinine ratio

Q24. A high ESR with normal CRP may suggest which of the following?

  • Very acute bacterial infection
  • Chronic inflammatory condition or anemia
  • Immediate allergic reaction
  • Purely viral infection

Correct Answer: Chronic inflammatory condition or anemia

Q25. Which of these tests is most useful for evaluating long-term glycemic control?

  • Fasting plasma glucose
  • Random blood glucose
  • HbA1c
  • Oral glucose tolerance test

Correct Answer: HbA1c

Q26. Which condition causes a microangiopathic hemolytic anemia with schistocytes on peripheral smear?

  • Iron deficiency
  • Thrombotic thrombocytopenic purpura (TTP)
  • Aplastic anemia
  • Vitamin B12 deficiency

Correct Answer: Thrombotic thrombocytopenic purpura (TTP)

Q27. Which measurement best indicates acute phase inflammation and responds rapidly to treatment?

  • ESR (erythrocyte sedimentation rate)
  • CRP (C-reactive protein)
  • Ferritin
  • Serum albumin

Correct Answer: CRP (C-reactive protein)

Q28. A patient has hyponatremia with low serum osmolality and high urine osmolality; what is the most likely mechanism?

  • Primary polydipsia
  • Sodium loss with volume depletion
  • Syndrome of inappropriate antidiuresis (SIADH)
  • Hyperglycemia causing osmotic shift

Correct Answer: Syndrome of inappropriate antidiuresis (SIADH)

Q29. Which hematology test helps distinguish iron deficiency anemia from anemia of chronic disease?

  • Serum ferritin
  • Serum sodium
  • Serum creatinine
  • Serum albumin

Correct Answer: Serum ferritin

Q30. In interpreting coagulation studies, an isolated prolonged aPTT that corrects with mixing study suggests which cause?

  • Factor deficiency (e.g., hemophilia)
  • Presence of lupus anticoagulant
  • Vitamin K deficiency
  • Thrombocytosis

Correct Answer: Factor deficiency (e.g., hemophilia)

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