Clinical Laboratory Tests Overview
A guide to hematology, biochemistry, and specialized diagnostics
I. Hematological Tests
Hematological tests analyze blood components to assess health, diagnose diseases, monitor treatment, and evaluate organ function.
1. Complete Blood Count (CBC)
Provides a general overview of blood health, detecting anemia, infection, and other disorders.
| Component | Description |
|---|---|
| Hemoglobin (Hb) | Measures oxygen-carrying capacity of blood. |
| Hematocrit (Hct) | Proportion of red blood cells to plasma. |
| RBC Count | Total number of erythrocytes. |
| MCV | Average size of RBCs (microcytic, normocytic, macrocytic). |
| MCH | Hemoglobin content per RBC. |
| MCHC | Hemoglobin concentration in RBCs. |
| WBC Count | Number of immune cells; elevated in infection or inflammation. |
| Platelet Count | Assesses clotting potential. |
2. White Blood Cell Differential
| Cell Type | Function |
|---|---|
| Neutrophils | Main defense in bacterial infections. |
| Lymphocytes | Viral infection response, immune regulation. |
| Monocytes | Chronic inflammation, antigen presentation. |
| Eosinophils | Parasitic infections, allergic reactions. |
| Basophils | Allergic and inflammatory mediator release. |
3–7. Other Hematology Tests
- Reticulocyte Count: Assesses bone marrow production of RBCs.
- Peripheral Blood Smear: Microscopic morphology check (e.g., sickle cells).
- ESR: Non-specific inflammation marker.
- Coagulation Profile:
Test Description PT Extrinsic pathway; warfarin monitoring. aPTT Intrinsic pathway; heparin monitoring. INR Standardized PT value. Fibrinogen Clotting factor and acute phase reactant. D-Dimer Indicates clot breakdown (DVT/PE, DIC). - Bone Marrow Aspiration/Biopsy: Evaluates marrow disorders, leukemia.
II. Biochemistry Tests
1. Electrolytes & Minerals
| Test | Purpose |
|---|---|
| Sodium | Maintains fluid balance, nerve conduction. |
| Potassium | Critical for cardiac/muscle function. |
| Chloride | Acid-base and osmotic balance. |
| Bicarbonate | Acid-base status indicator. |
| Calcium | Bone health, neuromuscular activity. |
| Magnesium | Enzyme function, cardiac rhythm stability. |
| Phosphate | Energy metabolism, bone mineralization. |
2–4. Organ Function Panels
- Renal Function: BUN, Creatinine, eGFR, Uric Acid.
- Liver Function: ALT, AST, ALP, GGT, Bilirubin, Albumin, Total Protein.
- Glucose & Diabetes: Fasting Glucose, OGTT, HbA1c, Insulin/C-peptide.
5–9. Additional Biochemistry
- Lipid Profile: Total Cholesterol, HDL, LDL, Triglycerides.
- Cardiac Markers: Troponin, CK-MB, Myoglobin, BNP.
- Thyroid Tests: TSH, Free T4/T3, thyroid antibodies.
- Pancreatic Function: Amylase, Lipase, Glucose.
- Inflammatory Markers: CRP, ESR, Ferritin, Procalcitonin.
- Nutritional Panel: Iron studies, B12, Folate, Vit D, Zinc/Copper.
- Hormonal Panel: Cortisol, ACTH, LH/FSH, sex hormones, Prolactin, PTH.
- Toxicology: Alcohol, drug levels, heavy metals.
III. Specialized & Emerging Tests
- Genetic Markers: BRCA1/2 (breast/ovarian cancer risk), Factor V Leiden (clotting), HFE (hemochromatosis).
- Autoimmune Panels: ANA (lupus), ENA, RF, anti-CCP (rheumatoid arthritis).
- Tumor Markers: PSA (prostate), CA-125 (ovarian), CEA (colon), AFP (liver/germ cell tumors).
- Expanded Metabolic Panels: Amino acids, organic acids, acylcarnitine profile for rare metabolic disorders.
References
- Hoffbrand AV, Moss PA. Essential Haematology. Wiley-Blackwell, 2020.
- Burtis CA, Bruns DE. Tietz Fundamentals of Clinical Chemistry. Elsevier, 2022.