Hematology Tests Overview

Hematology Tests

• Complete Blood Count (CBC)

  • Provides information about the types and numbers of cells in the blood.
  • Used to assess general health status and detect various disorders, including infection, anemia, inflammation, and bleeding disorders.
  • Erythrocyte Count
    • Lower values indicate anemia, post-hemorrhage, dehydration, and severe diarrhea.
    • Higher values suggest leukemia, dehydration, high altitudes, and polycythemia vera.
  • Mean Corpuscular Volume (MCV)
    • Lower values suggest microcytic anemia, folic acid and vitamin B12 deficiency, and liver disease.
    • Higher values indicate macrocytic anemia.
  • Mean Corpuscular Hemoglobin (MCH)
    • Lower values suggest microcytic anemia.
    • Higher values indicate macrocytic anemia.
  • Mean Corpuscular Hemoglobin Concentration (MCHC)
    • Lower values indicate hypochromic anemia.
    • Higher values indicate intravascular hemolysis and spherocytosis.

• Hemoglobin (Hgb)

  • Protein within red blood cells that carries oxygen.
  • Lower values indicate chronic blood loss and decreased dietary intake.
  • Higher values suggest chronic obstructive pulmonary disease, high altitudes, and polycythemia.
  • Normal ranges vary between males and females.

• Hematocrit or Packed Cell Volume (PCV)

  • Measures the volume of cells as a percentage of total blood volume.
  • Generally, three times greater than the hemoglobin value.
  • Lower values indicate hemorrhage, anemia, and excessive intravenous fluid infusion.
  • Higher values suggest dehydration, COPD, and congenital heart disease.

• Myoglobin (Mb)

  • Used for early evaluation of suspected acute myocardial infarction.
  • Helps diagnose skeletal muscle disease or injury.
  • Lower values indicate polymyositis.
  • Higher values suggest myocardial infraction, skeletal muscle inflammation (myositis), malignant hyperthermia, muscular dystrophy, skeletal muscle ischemia/trauma, and rhabdomyolysis.

• Natriuretic Peptides: BNP/or NP-proBNT42

  • Used to diagnose and categorize congestive heart failure (CHF).
  • Levels are higher in women, older individuals, and after cardiac surgery.
  • Higher values suggest CHF, myocardial infarction, systemic hypertension, heart transplant rejection, and cor pulmonale.
  • Normal ranges vary between ANP and BNP.

• Platelet Count (Thrombocytes)

  • Measures the number of platelets in the blood.
  • Often included in CBC when there are signs and symptoms of a bleeding disorder or excessive clotting.
  • Lower values (thrombocytopenia) indicate acute leukemia, chemotherapy, hemorrhage, toxic effect of medications, systemic lupus erythematosus, iron deficiency, and viral infections.
  • Higher values (thrombocytosis) suggest acute infections, chronic pancreatitis, cirrhosis, collagen disorders, and polycythemia vera.

• White Blood Cell Count (WBC)

  • Critical value: 1.5-2.0 times control value in seconds.

• Prothrombin Time (PT)

  • Normal international normalized ratio (INR): 0.8-1.2
  • Critical values: >20 seconds (for clients not taking anticoagulants).
  • Measures clotting times.
  • Used to check for bleeding problems or the chances of excessive bleeding during surgery.
  • Also used to monitor effectiveness of blood clot prevention medication.
  • Higher values suggest lack of or low levels of specific clotting factors, lack of vitamin K, and disseminated intravascular coagulation (DIC).

• Partial Thromboplastin Time (PTT)

  • Normal range: Activated partial thromboplastin time (aPTT): 30-40 seconds; Partial thromboplastin time (PTT): 60-70 seconds.
  • Clients receiving anticoagulant therapy: 1.5-2.5 times control value in seconds.
  • Critical values: aPTT > 70 seconds; PTT >100 seconds.
  • Used to monitor clients taking Heparin.
  • Measures clotting factors.
  • Checks the effectiveness of anticoagulants.
  • Higher values can indicate deficiency of various clotting factors, hemophilia, heparin therapy, liver disease, and low vitamin K.

• International Normalized Ratio (INR)

  • Normal range: 0.8-1.2.
  • Standardizes the results of prothrombin time tests.
  • Helps physicians understand results regardless of different testing methods.
  • Higher values indicate lack of or low levels of specific clotting factors, lack of vitamin K, and disseminated intravascular coagulation (DIC).

Diabetes Studies

• Fasting Plasma Glucose Test (FBS)

  • Screens for diabetes.
  • Requires fasting for at least 8 hours prior to testing.
  • Lower values can indicate hypoglycemia.
  • Higher values suggest prediabetes (6.0-7.0 mmol/L) and diabetes (>7.0 mmol/L).

• Oral Glucose Tolerance Test (OGTT)

  • Used to diagnose diabetes.
  • Measures blood glucose levels after consuming a sugary drink.
  • Results are generally evaluated in conjunction with other diagnostic tests.

• Hemoglobin A1C (HbA1c)

  • Measures the average blood glucose levels over the past 2-3 months.
  • Provides an indication of long-term blood sugar control.
  • A value of 6.9% or higher indicates diabetes.

Urine Tests

• Urinalysis (UA)

  • Often performed as part of a routine checkup.
  • Analyzes the physical and chemical properties of urine.
  • Physical properties include appearance, color, and odor.
  • Chemical properties include protein and specific gravity.

• Bilirubin Testing

  • Includes both direct and indirect bilirubin tests.
  • Elevated bilirubin levels (>2.5-3 mg/dL) cause jaundice.
  • Provides insights into liver function and potential pathology.

• Hemoglobin (Hb)

  • Anemia

    • Indicates a decrease in total hemoglobin levels in the blood.

    • Can result from various factors, categorized based on red blood cell size.

      • Microcytic Anemia: Low hemoglobin with a reduced MCV.
      • Macrocytic Anemia: Low hemoglobin with an increased MCV.
      • Normocytic Anemia: Low hemoglobin with a normal MCV.

    • Normocytic Anemia Causes:

      • Anemia of chronic disease/inflammation
      • Acute blood loss
      • Increased plasma volume
      • Mixed etiologies
      • Haemoglobinopathies
      • Aplastic anemia
      • Hemolysis
      • Hypersplenism