How to Interpret Your Blood Test Results and Understand Key Metrics

Medically Reviewed By: Jillian Foglesong, MD, FAAFP

Blood tests are an essential tool in modern healthcare, providing a snapshot of your overall health and helping doctors diagnose conditions early. Understanding how to interpret your blood test results can be confusing, especially when faced with medical jargon and a list of numbers. This guide will break down the most common metrics you might encounter in your blood test results and explain what they mean for your health.

Whether you're reviewing results for a routine checkup, managing a chronic condition, or taking proactive steps in maintaining your well-being, interpreting your blood test results is crucial to understanding your health.

Blood Test Metrics and What They Mean

Red Blood Cell Count (RBC)

Red blood cells are responsible for carrying oxygen throughout your body. The RBC count helps diagnose anemia (low RBC) or polycythemia (high RBC), both of which can impact oxygen delivery to tissues. [1]

• Low RBC count may indicate anemia, blood loss, or nutritional deficiencies (like iron, B12, or folate). [1]
• High RBC count could suggest dehydration or a condition like polycythemia vera. [1]

White Blood Cell Count (WBC)

White blood cells are a part of your immune system, fighting off infections. A WBC count can help detect infections, inflammation, or immune system disorders. [2]

• High WBC count may suggest infection, inflammation, or immune-related diseases. [2]
• Low WBC count can indicate bone marrow problems, certain infections, or autoimmune conditions. [2]

Platelet Count

Platelets help with blood clotting. The platelet count is vital in assessing your body’s ability to stop bleeding when injured. [3]

• Low platelet count may be due to a blood disorder or medication side effects.
• High platelet count might suggest inflammation, infection, or a bone marrow disorder.

Hemoglobin (Hgb)

Hemoglobin is the protein in red blood cells that carries oxygen. A low hemoglobin level can indicate anemia, while a high level might point to lung or heart conditions. [4]

• Low hemoglobin can cause fatigue, weakness, and shortness of breath. [4]
• High hemoglobin can be seen in conditions like chronic lung disease or living at high altitudes. [4]

Glucose

Glucose is the body’s main source of energy, and its level in the blood is a key indicator of metabolic health. Blood glucose tests are often used to diagnose diabetes or monitor existing diabetes. [5]

• High glucose levels can indicate diabetes or prediabetes. [5]
• Low glucose levels can be a sign of hypoglycemia, which might lead to dizziness, confusion, or fainting. [5]

Cholesterol and Lipid Profile

Your lipid profile measures cholesterol (HDL, LDL) and triglyceride levels, which are important markers for heart disease risk. High levels of LDL (bad cholesterol) and triglycerides, combined with low HDL (good cholesterol), can increase your risk of heart attack or stroke (Cleveland Clinic).

• High LDL or total cholesterol is a major risk factor for cardiovascular disease.
• Low HDL can lead to an increased risk of heart disease.

Thyroid Function Tests

Thyroid hormones control metabolism. The TSH test is commonly used to measure thyroid function, helping to diagnose conditions like hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid).

• High TSH levels suggest hypothyroidism, where your thyroid is underactive and can cause fatigue, weight gain, and depression.
• Low TSH levels indicate hyperthyroidism, leading to symptoms like weight loss, rapid heart rate, and anxiety.

Kidney and Liver Function Tests

Tests like creatinine, BUN (blood urea nitrogen), and liver enzymes (AST, ALT) assess how well your kidneys and liver are functioning. Abnormal levels can point to kidney disease, liver damage, or dehydration (Healthline).

• High creatinine or BUN could suggest kidney dysfunction.
• Elevated liver enzymes may indicate liver damage, inflammation, or infection.

How to Interpret Your Blood Test Results

When reviewing your blood test results, it’s important to remember that lab results often come with reference ranges. These ranges can vary depending on factors like age, gender, and the laboratory conducting the test. Your healthcare provider will assess your results in the context of your overall health, medical history, and symptoms.

If you see results outside the normal range, don’t panic. Many factors, including diet, exercise, stress, and medications, can influence blood test results. Always follow up with your healthcare provider to discuss your results and get personalized recommendations.

Steps to Take After Getting Your Blood Test Results

• Review the Reference Range: Understand what the normal range is for each test and compare it with your results. Your doctor will explain any abnormalities.
• Ask Questions: Don’t hesitate to ask your doctor what each result means, particularly if you see values outside the normal range.
• Follow Up with Additional Testing: Sometimes, a single test may not provide enough information. Your doctor may suggest additional tests to get a clearer picture.
• Take Action: Based on your results, your healthcare provider might recommend lifestyle changes, medications, or further monitoring to manage your health.

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A blood test is a crucial tool in understanding your overall health. It provides essential insights into various bodily functions and can help detect conditions like anemia, infections, and blood disorders. Everlywell provides convenience of at home tests and offers comprehensive full body test with Everlywell 360. One in-person blood and urine test measures 83 biomarkers across six key health categories—and your results don’t stop at numbers. With Everlywell 360, you also get a provider-reviewed Care Plan and a unique WellScore so you can track your health year over year.

Learn more

1. Red blood cell (RBC) count. MedlinePlus. Updated July 31, 2022. Accessed April 23, 2025. https://medlineplus.gov/lab-tests/red-blood-cell-rbc-count/.
2. Cherney K. WBC count: what it is and what it means. Healthline. Updated October 27, 2023. Accessed April 23, 2025. https://www.healthline.com/health/wbc-count.
3. Platelet count. Cleveland Clinic. Reviewed May 3, 2023. Accessed April 23, 2025. https://my.clevelandclinic.org/health/diagnostics/21782-platelet-count.
4. Low hemoglobin: causes, symptoms, and treatment. Cleveland Clinic. Reviewed October 6, 2022. Accessed April 23, 2025. https://my.clevelandclinic.org/health/symptoms/17705-low-hemoglobin.
5. Weaver M. Glucose levels: what they are and what they mean. Healthline. Updated December 18, 2023. Accessed April 23, 2025. https://www.healthline.com/health/glucose.