BLOOD TEST RESULTS: HOW TO UNDERSTAND THEM AND ACT IN THE EVENT OF AN ANOMALY?
The results of a blood test are a valuable source of health information. They can be used to detect diseases, monitor the progress of a treatment or refine a medical diagnosis. These analyses, carried out from a blood sample, are commonly used to assess various biological parameters.
Understanding the values listed on your results can seem complex. Between reference standards, variations by age or gender, and the impact of certain treatments, their interpretation requires special attention. Did you know that factors such as fasting or physical activity can also influence these data?
What is a blood test result?
A blood test result corresponds to the interpretation of biological data collected from a blood sample. The information obtained is grouped in a document mentioning reference values (RV) , which vary according to age, sex and the methods used in the laboratory.These results assess different biological parameters , such as glucose (glycemia), lipids (cholesterol), or inflammatory markers. In the event of deviations from the reference values , it is essential to consult a doctor, because anomalies do not always mean the presence of a disease. Certain factors, such as drug treatments or diet, can temporarily influence these data.In the laboratory, each analysis displays specific units according to the standards used. For example, for blood sugar, a value of 7 mmol/L or more , measured twice, indicates diabetes. This type of indication helps health professionals make an accurate diagnosis and propose appropriate follow-up.
Common tests in a blood test
A blood test is a common medical examination used to assess various biological parameters. Here is an overview of the major analyses:
The complete blood count (CBC)
The complete blood count (CBC), also called a blood count (CBC) , analyzes the different blood components: red blood cells , white blood cells and platelets . This analysis detects abnormalities such as anemia , infections or clotting disorders. The results are essential for diagnosing and monitoring many pathologies.
The glycemic balance
Blood glucose testing measures the concentration of glucose in the blood when fasting. A blood glucose level greater than or equal to 126 g/L may indicate the presence of diabetes. This assessment is also useful for assessing metabolic risks and monitoring the effectiveness of treatments in diabetic patients.
Lipid balance
This assessment evaluates HDL and LDL cholesterol levels as well as triglycerides . Essential for analyzing the risk of cardiovascular disease, it helps identify lipid disorders. Excess LDL or triglycerides require management in order to prevent complications.
Liver function tests
A liver function test , a blood test, evaluates the function and health of the liver . It is often ordered to detect inflammation, liver damage, or dysfunction. Viral hepatitis, family history of liver disease, chronic alcoholism, and certain hepatotoxic medications are common reasons for this test.
This assessment includes the measurement of liver enzymes , particularly transaminases, which increase during the destruction of liver cells. A high level of cholestasis enzymes can indicate pathologies such as an obstacle to biliary drainage. Bilirubin , a pigment derived from hemoglobin, is also analyzed. An accumulation in the blood causes jaundice, a symptom of a liver abnormality.
At the same time, the dosage of albumin , a protein essential for the transport of substances, indicates an alteration of liver function if its levels are low. To ensure reliable results, a sample is taken on an empty stomach, after 12 hours of fasting, from the crease of the elbow via a venipuncture. The analysis is then carried out in a specialized laboratory.
The renal assessment
A kidney test is a key assessment to measure the health and functioning of the kidneys. It uses blood and sometimes urine tests to detect potential kidney dysfunction or disease. Key parameters tested include creatinine , urea nitrogen, and uric acid, each of which reflects a specific aspect of kidney function.
Creatinine , derived from the breakdown of muscle creatine, is a central indicator. Its level, normally 60 to 115 µmol/l (men) and 45 to 105 µmol/l (women), varies according to muscle mass but becomes problematic in the event of a significant increase. This excess in the blood indicates insufficient renal filtration.
Urea , produced during protein digestion, is a nitrogenous waste eliminated by the kidneys. A normal concentration is between 2.5 and 7.5 mmol/l. Its diagnostic role is supplemented by other tests, because its level can vary depending on diet.
Uric acid , with a reference range of 120 to 420 µmol/l, is also monitored during the assessment. An accumulation can cause kidney stones or gout, indicating ineffective renal elimination.
Inflammatory markers
The erythrocyte sedimentation rate (ESR) measures the time it takes for red blood cells to settle to the bottom of a tube after one hour. Expressed in millimeters, a high value often indicates inflammation, infection , or diseases such as cancer and vasculitis. It is frequently used to identify chronic inflammatory or infectious disorders.
C-reactive protein (CRP) , produced by the liver, is a key indicator in cases of infections or inflammation. Its blood level increases rapidly during an acute episode and decreases when the condition improves. Compared to ESR, CRP reacts more quickly, making it a powerful marker for detecting inflammatory syndromes or bacterial diseases.
How to interpret the results?
Interpreting the results of a blood test combines comparing the values obtained with reference values and analyzing them according to the patient’s medical context. This requires professional expertise to arrive at an accurate assessment.
Understanding Reference Values
Reference values are normative figures determined by statistical studies on patients of different groups (age, gender). These values vary depending on the laboratory techniques used. For example, normal hemoglobin is between 12 and 16 g/100 ml for women and 13 and 18 g/100 ml for men. Any deviation does not necessarily indicate a disease, since elements such as treatments or diet can temporarily influence the results.
Who should I contact for a reliable interpretation?
A physician or medical laboratory specialist interprets the results based on symptoms , medical history, and additional tests. Although laboratory reports may indicate abnormalities, only a professional can make an accurate diagnosis or identify an underlying problem. A consultation with the prescribing physician ensures appropriate management and relevant follow-up.
Advice in case of abnormal results
In case of abnormal results , it is essential not to panic. Some biological variations may be temporary or due to external influences such as medications or diet. A consultation with a doctor helps to understand these deviations and assess their seriousness in a medical context.
To further investigate, the doctor may order additional tests, such as an ultrasound or specific tests, to confirm or rule out a diagnosis. High or low levels of certain parameters, such as blood sugar or creatinine , may indicate an underlying condition that requires monitoring.
Adopting corrective measures , such as a suitable diet or changing drug treatments in agreement with the doctor, often allows normal values to be restored. In the case of chronic diseases such as diabetes or hypertension, regular monitoring of biological parameters is essential to limit the risks of complications.
Frequently Asked Questions
Why is it necessary to fast before a blood test?
Fasting helps prevent food or beverages from influencing the results of certain parameters, such as blood sugar or cholesterol. Fasting for 8 to 12 hours is often required to obtain reliable results.
What does a result outside the reference values mean?
A result outside the reference values does not automatically mean a disease. These deviations may be due to factors such as drug treatment, a specific diet or recent physical effort. Consult a doctor for an appropriate interpretation.
What are the most common blood tests?
The most frequently performed tests include the blood count (or CBC), glycemic, lipid, hepatic and renal tests. These tests can be used to detect abnormalities, monitor pathologies or refine a medical diagnosis.
What factors can influence the results of a blood test?
Results may be affected by age, gender, medications, diet, fasting or physical activity. It is important to follow medical recommendations before taking a sample.
Why consult a doctor after abnormal results?
A doctor is essential to interpret the results taking into account your medical history, your symptoms and the overall context. An isolated analysis is not enough to make an accurate diagnosis.
How does a blood test detect diseases?
Blood tests identify abnormalities, such as deficiencies, inflammation, or organ dysfunction. For example, high blood sugar may signal diabetes, or high CRP may indicate inflammation.
What is the difference between erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP)?
ESR measures the time it takes for red blood cells to settle, indicating possible inflammation. CRP, which is more reactive, quickly detects inflammation or infection in the body.
How to properly prepare for a blood test?
Follow medical instructions: fast if required, hydrate yourself by drinking only water, avoid physical exertion and inform your doctor of any current treatment.
Why do reference values vary between laboratories?
Laboratories use different techniques and methodologies to analyze samples, which may result in slight variations in the proposed reference values.
What to do if you get worrying results?
Don’t panic. Seek prompt medical attention for a thorough evaluation. Additional testing or follow-up care may be needed to confirm or rule out a diagnosis.