A blood test, often called a blood panel, is a crucial laboratory examination of a blood sample. It serves as a window into your health, providing valuable insights into the function of vital organs like the liver, kidneys, thyroid, and heart. Furthermore, blood tests are instrumental in detecting infections, genetic disorders, and assessing your overall well-being. 1 Understanding the results of these tests is a key step towards accurate Diagnosis Based On Lab Results.
Once your blood sample is analyzed, you’ll typically receive a blood test report. This report is a detailed breakdown of your blood’s components and their levels. However, for individuals without a medical background, interpreting these reports can be daunting. The medical jargon and numerical values can seem complex and confusing. This guide aims to demystify blood test results, helping you understand how they contribute to medical diagnosis based on lab results.
Common Abbreviations in Blood Test Reports
Blood test results are presented using the metric system and a range of abbreviations. Familiarizing yourself with these common abbreviations can make your report less intimidating:
- cmm: Cells per cubic millimeter
- fL (femtoliter): Femtoliter, a fraction of a millionth of a liter
- g/dL: Grams per deciliter
- IU/L: International units per liter
- mEq/L: Milliequivalent per liter
- mg/dL: Milligrams per deciliter
- mL: Milliliter
- mmol/L: Millimoles per liter
- ng/mL: Nanograms per milliliter
- pg (picograms): Picograms, one-trillionth of a gram
For those seeking immediate health insights, symptom assessment apps like the Ada app can be helpful. You can also learn more about symptom checkers and their functionality through resources like our symptom checker guide. However, remember that these tools are not a substitute for professional medical diagnosis based on lab results.
Key Components of a Blood Test Report
A standard blood test usually encompasses three major panels: Complete Blood Count (CBC), Metabolic Panel, and Lipid Panel. 2 Each panel focuses on different aspects of your health, and a thorough analysis of their results is crucial for accurate diagnosis based on lab results.
It’s important to note that your report might not separate these three panels distinctly. Instead, you may find all the tests listed under a single column, often labeled “Test Name.” Within this column, various sub-tests are listed, providing a comprehensive overview of your health status which aids in diagnosis based on lab results.
Complete Blood Count (CBC): A Detailed Look
The Complete Blood Count (CBC) is centered around the three primary types of blood cells: White Blood Cells (WBCs), Red Blood Cells (RBCs), and Platelets. By measuring the quantity and characteristics of these cells, a CBC helps doctors evaluate your overall health and screen for underlying conditions like leukemia and anemia. 3 This detailed cellular analysis is a cornerstone of diagnosis based on lab results.
The CBC panel includes these key subtests:
White Blood Cell (WBC) Count: Immune System Indicator
White blood cells, also known as leukocytes, are vital components of your body’s immune defense. An elevated WBC count often signals the presence of an infection, as the body mobilizes its defenses. Conversely, a low WBC count can be indicative of various conditions, including HIV, leukemia, hepatitis, and arthritis. 4 Analyzing WBC counts is essential for infection diagnosis based on lab results.
Read more about White Blood Cell Count »
Differential White Blood Cell Count: Identifying Infection Types
This test goes beyond the total WBC count by examining the five main types of white blood cells and their proportions relative to each other. Imbalances in these proportions can pinpoint specific types of infections or other medical conditions. The typical healthy ranges are:
- Neutrophils: 40% to 60% of total WBCs
- Lymphocytes: 20% to 40%
- Monocytes: 2% to 8%
- Eosinophils: 1% to 4%
- Basophils: 0.5% to 1%
This detailed differentiation is crucial for refined diagnosis based on lab results, helping to distinguish between bacterial, viral, or allergic reactions.
Red Blood Cell (RBC) Count: Oxygen Delivery Assessment
Red blood cells (RBCs) are responsible for transporting oxygen to tissues throughout your body, making them essential for overall health. The RBC count measures the volume of RBCs in your blood. Results outside the normal range (either high or low) can suggest various medical conditions. However, this test alone doesn’t identify the underlying cause of any abnormalities, often requiring further investigation for accurate diagnosis based on lab results. 3
Hematocrit (Hct) Test: Proportion of Red Blood Cells
The Hematocrit (Hct) test determines the percentage of your blood volume composed of RBCs. It’s a valuable tool in diagnosing anemia and other conditions affecting blood composition. Hematocrit levels are a key factor in diagnosis based on lab results related to blood disorders.
Hemoglobin (Hgb) Test: Oxygen-Carrying Protein
Hemoglobin is a protein within RBCs that carries oxygen from your lungs to your body’s tissues. The hemoglobin test is another important test for diagnosing anemia, and many doctors prefer it over the hematocrit test for its direct measurement of the oxygen-carrying capacity of the blood. 5 Hemoglobin levels are directly linked to oxygen transport and crucial for diagnosis based on lab results for oxygenation issues.
Read more about Hemoglobin Levels ».
Mean Corpuscular Volume (MCV) Test: Red Blood Cell Size
The Mean Corpuscular Volume (MCV) test measures the average size of your RBCs, indicating the space each cell occupies. Abnormal MCV results can be a sign of anemia, chronic fatigue syndrome, and other medical conditions. RBC size, as measured by MCV, is important in diagnosis based on lab results related to different types of anemia.
Mean Corpuscular Hemoglobin (MCH) Test: Hemoglobin per Red Blood Cell
The Mean Corpuscular Hemoglobin (MCH) test measures the average amount of hemoglobin within each RBC. Elevated MCH levels may suggest anemia, while low MCH levels could indicate malnutrition. Hemoglobin quantity per RBC, measured by MCH, is informative for nutritional diagnosis based on lab results. 6
Red Cell Distribution Width (RDW or RCDW) Test: Variation in Red Blood Cell Size
The Red Cell Distribution Width (RDW or RCDW) test assesses the variation in the size of your RBCs, rather than their average size. Abnormal RDW levels can point to conditions like anemia, malnutrition, and liver disease. The uniformity of RBC size, assessed by RDW, provides further detail for diagnosis based on lab results.
Platelet Count: Blood Clotting Cells
Platelets are tiny cells that play a critical role in blood clotting. The platelet count measures the number of platelets in your blood. A high platelet count can indicate anemia, cancer, or infection, while a low count can impair wound healing and lead to excessive bleeding. Platelet count is essential for diagnosis based on lab results related to bleeding disorders and certain diseases.
Mean Platelet Volume (MPV): Platelet Size
The Mean Platelet Volume (MPV) test measures the average size of platelets in your blood. A low MPV can contribute to bleeding irregularities, while a high MPV can increase the risk of heart attack or stroke. Platelet size, as measured by MPV, adds another layer of information for diagnosis based on lab results concerning cardiovascular risks and bleeding tendencies.
Image: Microscopic view of blood cells, highlighting red blood cells, white blood cells, and platelets.
Comprehensive Metabolic Panel (CMP): Assessing Body Chemistry
The Comprehensive Metabolic Panel (CMP), also known as a chemistry panel, provides a broad assessment of your body’s chemical balance. It measures glucose levels, fluid and electrolyte balance, and liver and kidney function. 7 The CMP is a vital tool in diagnosis based on lab results related to metabolic and organ function. It comprises several sub-tests:
Alanine Aminotransferase (ALT) Test: Liver Enzyme
Alanine aminotransferase (ALT) is an enzyme primarily produced by liver cells. 8 Elevated ALT levels are a strong indicator of liver damage. ALT levels are a key marker for liver health in diagnosis based on lab results.
Albumin Test: Liver Protein
Albumin is a protein produced by the liver. The albumin test measures the amount of albumin in your blood. Abnormal levels can be caused by liver or kidney problems. Kidney problems can also affect albumin levels. Albumin levels are important for assessing liver and kidney function in diagnosis based on lab results.
Total Protein Test: Albumin-Globulin Ratio
This test measures the total amount of protein in your blood, including albumin and globulin. It also looks at the ratio of these two protein types. Low total protein levels can suggest liver and kidney disorders or malnutrition, while high levels may indicate inflammation, infection, or bone marrow disorders. 9 Protein levels and ratios contribute to broader diagnosis based on lab results concerning nutritional status and various diseases.
Alkaline Phosphatase Test: Liver and Bone Enzyme
Alkaline phosphatase is an enzyme found mainly in liver and bone cells. Abnormal levels can signal liver damage and bone problems like rickets or bone tumors. 9 Alkaline phosphatase is another important enzyme for liver and bone health assessment in diagnosis based on lab results.
Aspartate Aminotransferase (AST) Test: Enzyme in Multiple Organs
Aspartate aminotransferase (AST) is an enzyme present in RBCs, muscle tissue, heart, pancreas, liver, and kidneys. This test measures AST levels in your blood. Elevated levels can indicate various conditions, including certain cancers, and damage to the liver, heart, or kidneys. 9 AST levels provide insights into the health of multiple organs for comprehensive diagnosis based on lab results.
Bilirubin Test: Liver and Red Blood Cell Breakdown
Bilirubin is a biomarker used to assess liver and kidney function and red blood cell breakdown. It’s helpful in diagnosing conditions like neonatal jaundice, anemia, and liver diseases. 9 Bilirubin levels are crucial for diagnosis based on lab results related to liver function and hemolytic conditions.
Blood Urea Nitrogen (BUN) Test: Kidney Function
The Blood Urea Nitrogen (BUN) test measures the amount of nitrogen in your blood in the form of urea. High BUN levels can be caused by kidney damage or disease, while low levels might indicate malnutrition or severe liver damage. 9 BUN levels are a primary indicator of kidney function in diagnosis based on lab results.
Calcium Test: Mineral Balance
This test measures calcium levels in your blood. Low calcium levels can suggest underactive parathyroid glands, insufficient dietary calcium, or vitamin D deficiency. High calcium levels can indicate overactive parathyroid glands, excessive vitamin D supplementation, kidney problems, and other more serious conditions requiring further investigation. 10 Calcium levels are important for diagnosis based on lab results related to parathyroid function, vitamin D status, and kidney health.
Chloride Test: Electrolyte Balance
The chloride test measures chloride levels in your body. Increased chloride levels can indicate dehydration, kidney disorders, and adrenal gland dysfunction. 11 Chloride levels are part of electrolyte balance assessment in diagnosis based on lab results.
Creatinine Test: Kidney Waste Product
Creatinine is a waste molecule essential for muscle energy creation. Elevated creatinine levels can be a sign of kidney dysfunction. Creatinine is a key marker for kidney function in diagnosis based on lab results.
Fasting Blood Sugar Test: Glucose Levels
Blood sugar levels are easily influenced by recent food or drink intake. The fasting blood sugar test is performed after at least six hours of fasting. Abnormal results can indicate diabetes and other medical conditions. Fasting blood sugar is essential for diagnosis based on lab results related to diabetes and glucose metabolism.
Phosphorus Test: Mineral Balance
This test measures phosphorus levels in your blood. Elevated levels can suggest problems with the kidneys and parathyroid glands, and they may also indicate malnutrition or alcohol abuse. Phosphorus levels are relevant for diagnosis based on lab results related to kidney and parathyroid function and nutritional status.
Potassium Test: Electrolyte and Muscle Function
Potassium is crucial for nerve and muscle communication, heart regulation, and muscle function. Diuretics can cause potassium levels to decrease. Potassium levels are vital for heart and muscle function assessment in diagnosis based on lab results.
Sodium Test: Electrolyte and Fluid Balance
Sodium is a mineral that aids nerve impulses, muscle contractions, and water balance. Irregular sodium levels can indicate dehydration, adrenal gland disorders, corticosteroid use, and kidney or liver disorders. Sodium levels are key to fluid and electrolyte balance assessment in diagnosis based on lab results.
Image: A healthcare professional drawing blood from a patient’s arm for laboratory testing.
Lipid Panel: Assessing Cholesterol and Fats
The lipid panel comprises tests that measure different types of triglycerides (fats) and cholesterol in your blood. This panel is crucial for assessing cardiovascular risk and plays a significant role in diagnosis based on lab results related to heart health.
Total Cholesterol Test: Overall Cholesterol Levels
This test measures the total amount of cholesterol in your blood, including both LDL (“bad”) and HDL (“good”) cholesterol. Total cholesterol levels are a primary indicator of overall cholesterol status in diagnosis based on lab results.
Triglycerides Test: Blood Fats
This test measures triglycerides, a type of fat found in your blood. Irregular triglyceride levels are a potential risk factor for heart disease and other medical conditions. Triglyceride levels are a key component of lipid assessment in diagnosis based on lab results for cardiovascular risk.
HDL Cholesterol Test: “Good” Cholesterol
HDL cholesterol, or high-density lipoprotein, is known as “good” cholesterol because it helps protect against heart disease. Low HDL levels can increase the risk of heart problems. HDL cholesterol levels are a protective factor against heart disease and important in diagnosis based on lab results for heart health.
LDL Cholesterol Test: “Bad” Cholesterol
LDL cholesterol, or low-density lipoprotein, is considered “bad” cholesterol as it’s linked to heart disease and clogged arteries. Elevated LDL levels contribute to heart disease risk and are crucial in diagnosis based on lab results for cardiovascular health.
Total Cholesterol to HDL Ratio Test: Heart Disease Risk
This ratio is calculated by dividing total cholesterol by HDL cholesterol. It helps determine an individual’s risk of developing heart disease. A high ratio suggests a higher risk of heart problems. 12 This ratio provides a comprehensive view of heart disease risk in diagnosis based on lab results from the lipid panel.
Footnotes:
[1] Mayo Clinic. (n.d.). Blood test. https://www.mayoclinic.org/tests-procedures/blood-tests/about/pac-20385394
[2] National Library of Medicine. (n.d.). Blood tests. https://medlineplus.gov/bloodtests.html
[3] National Heart, Lung, and Blood Institute. (n.d.). Complete Blood Count (CBC). https://www.nhlbi.nih.gov/health-topics/complete-blood-count
[4] Cleveland Clinic. (2022, March 29). White Blood Cell Count. https://my.clevelandclinic.org/health/diagnostics/15070-white-blood-cell-count
[5] Johns Hopkins Medicine. (n.d.). Hemoglobin Test. https://www.hopkinsmedicine.org/health/wellness-and-prevention/hemoglobin-test
[6] Mount Sinai. (n.d.). MCH (Mean Corpuscular Hemoglobin). https://www.mountsinai.org/health-library/tests/mch-mean-corpuscular-hemoglobin
[7] University of Rochester Medical Center. (n.d.). Comprehensive Metabolic Panel (CMP). https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=cmp_comprehensive_metabolic_panel
[8] Mayo Clinic. (n.d.). ALT test. https://www.mayoclinic.org/tests-procedures/alt/about/pac-20393015
[9] UW Medicine. (n.d.). Comprehensive Metabolic Panel. https://www.uwmedicine.org/lab-services/test-guide/Pages/comprehensive-metabolic-panel.aspx
[10] National Kidney Foundation. (n.d.). Calcium. https://www.kidney.org/atoz/calcium
[11] MedlinePlus. (n.d.). Chloride blood test. https://medlineplus.gov/lab-tests/chloride-blood-test/
[12] American Heart Association. (2017, November 17). Know Your Fats. https://www.heart.org/en/health-topics/cholesterol/hdl-cholesterol-good-cholesterol/hdl-cholesterol
