Understanding laboratory values: The most important abbreviations
Table of Contents
ToggleBlood and urine tests provide doctors with information about a person’s health, such as the kidneys, liver or heart. But what do the laboratory values mean? We reveal which abbreviations you should know in connection with vital organs and their diseases and help you to better understand your laboratory values.
What lab values really mean
Laboratory values are like pieces of a jigsaw puzzle for medical professionals: in addition to other tests, they play an important role in the diagnosis of diseases. Laboratory values can indicate an infection before other symptoms, they can serve as evidence of a suspected illness or monitor the success of a therapy over the course of time.
However, laboratory values should never be considered in isolation. Because it is usually not just a single laboratory value that decides whether a disease is actually present. Certain disruptive factors must also be taken into account when assessing laboratory values. Stress or heavy physical exertion can change laboratory values. It is also possible that food intake or medication intake can influence the results.
Do not be unsettled by laboratory values
It is not unusual for reference values to be subject to fluctuations. You can even find various information on the standard values in the specialist literature, since the values are constantly being adapted to new scientific findings. Even from laboratory to laboratory, different reference values are considered normal depending on the method. Anyone who checks their laboratory results should therefore not be alarmed if there are deviations.
In order to finally interpret laboratory values, the entire knowledge of the doctor is required, who takes all factors into account for the diagnosis. If in doubt, always ask your doctor for advice.
CRP: laboratory value in infections and inflammations
The CRP value is considered an important parameter among laboratory values and can be determined by a blood test . The abbreviation CRP stands for C-reactive protein. This is a protein that is formed in the liver and whose production is greatly increased after just a few hours in the event of inflammation or infection.
The laboratory value is also particularly suitable for diagnostics because it quickly drops again after the inflammation or infection has subsided. It also increases more in bacterial infections, which allows a viral infection to be distinguished from a bacterial infection. Antibiotic therapy can also be monitored by determining the CRP concentration.
- Normal value for CRP: ≤ 5.0 mg/l (milligrams per liter)
What do elevated laboratory values mean?
There are different causes for increased laboratory values: The CRP value can be just as revealing in appendicitis as in bacterial pneumonia . The clinical symptoms must therefore also be taken into account for the diagnosis. A greatly increased concentration of over 100 mg/l can indicate a severe infection.
In addition, other inflammation parameters are examined if acute infections are suspected: blood sedimentation rate (ESR), immunoglobulins (Ig) and the number of white blood cells (leukocytes).
GOT and GPT: liver laboratory values
In order to detect acute or chronic liver disease , laboratory tests focus on GOT (also known as AST/aspartate aminotransferase) and GPT (also known as ALT/alanine aminotransferase). GOT stands for glutamic oxaloacetic transaminase, GPT for glutamic pyruvic transaminase. Both are enzymes found in the liver, among other organs. If there is liver damage, they increasingly enter the blood.
- Reference range in women: 10 to 35 U/l (units per liter, unit = unit of measure for enzyme activity)
- Reference range for men: 10 to 50 U/l
What do elevated laboratory values mean?
Elevated laboratory values can indicate, for example, alcohol-related liver damage, infectious liver inflammation or liver cirrhosis . Even with slight liver damage, these values can be increased. However, certain drugs also affect the laboratory values and can therefore also be considered as the cause of a slight increase.
If liver damage is suspected, further examination methods must be used to get to the bottom of it. In the case of severe liver damage, another laboratory value also plays a role: GLDH (glutamate dehydrogenase) only gets into the blood if the liver cells die.
Cholesterol levels: too high or too low?
Cholesterol is not just cholesterol: The “bad” LDL cholesterol (low-density lipoprotein cholesterol) is deposited in the blood vessels and threatens to clog them. “Good” HDL cholesterol (high-density lipoprotein cholesterol), on the other hand, is responsible for its removal and protects the vessels. For this reason, a low LDL concentration and a high HDL concentration in the blood are desirable.
The normal values for LDL cholesterol depend on other existing risk factors for the development of heart disease. These include: smoking, lack of exercise, diabetes mellitus and high blood pressure . In laboratory tests, the total cholesterol is also determined.
- Reference value for total cholesterol: ≤ 190 mg/dl (milligrams per deciliter)
- Reference value for HDL in women: ≥ 50 mg/dl
- Reference value for HDL in men: ≥ 40 mg/dl
- Reference value for LDL:
- < 160 mg/dl with no or one risk factor
- < 130 mg/dl if two or more risk factors exist
- < 100 mg/dl if arteriosclerosis or coronary artery disease is already present
What do elevated laboratory values mean?
An elevated cholesterol level in the blood is considered a warning signal for an increased risk of arteriosclerosis, heart attack or stroke. Therefore, the determination of laboratory values here is an important tool for the early detection of heart disease.
If the cholesterol levels are too high, the doctor will initiate a therapy that is suitable for the individual case. Most of the time, it involves lifestyle changes—quitting smoking, eating healthily, and exercising more. Medications can also be used to lower cholesterol levels.
TSH: laboratory value of the thyroid gland
The thyroid fulfills important functions in the body: Among other things, it produces the hormones T3 (triiodothyronine) and T4 (tetraiodothyronine) in order to regulate various metabolic processes. The production of these hormones is in turn controlled by a hormone from the pituitary gland (pituitary gland) – TSH (thyroid-stimulating hormone). If there is a suspicion of a dysfunction of the thyroid gland, the TSH level in the blood is determined. Laboratory tests are also used to monitor treatments with thyroid hormones.
- Reference value for TSH in adults: 0.40 to 4.0 mU/l (milli-units per liter)
What do high or low laboratory values mean?
If the TSH value is normal, there is usually no malfunction of the thyroid gland. An elevated laboratory value can indicate an underactive thyroid gland , a low value an overactive thyroid gland . Depending on the result, T3, T4 and the biologically active forms free T3 (fT3) and free T4 (fT4) are determined for further diagnostics.
GFR: Early detection of kidney damage
If kidney damage is suspected, the GFR value can be determined via a urine test. The abbreviation stands for “glomerular filtration rate”: It indicates how many milliliters of blood a healthy kidney cleans of filterable substances ( creatinine ) per minute and excretes through the urine. This laboratory value is important in order to be able to assess the function of the kidneys.
- Reference value for GFR: 90 to 130 milliliters per minute
What do the laboratory values mean?
As a laboratory value, GFR is used to assess chronic kidney weakness. It is divided into five stages. In the first stage, the laboratory value can be used primarily for the early detection of kidney disease in order to prevent the disease from getting worse in good time. Because: In this phase, there are often no symptoms and the blood values are normal – but the GFR value already provides the first indication of a disease.
CR, troponin and LDH: laboratory values in myocardial infarction
Severe pain behind the breastbone, which may radiate into the left arm, jaw, back or upper abdomen, as well as feelings of anxiety, shortness of breath and nausea are typical symptoms of a heart attack – and a case for the emergency doctor!
In addition to other examinations such as the ECG, doctors can also determine whether it is actually a heart attack through laboratory tests. Because if the heart suddenly fails, it sends signals that become visible in the blood. However, other causes such as epileptic seizures or poisoning can also be behind elevated laboratory values, which is why all the factors present must always be taken into account for the diagnosis.
cTnT (Troponin T) und cTnI (Troponin I)
These are proteins for muscle contraction that are only found in the heart muscle and are not found in the blood of healthy people. About three hours after a heart attack, troponin levels rise. In order to obtain a laboratory result as quickly as possible, highly sensitive troponin T tests are usually used today.
- Referenzbereich Troponin T hs (Troponin T high sensitive): < 14 ng/l (Nanogramm pro Liter)
CK (Creatinkinase)
This enzyme is increasingly released into the blood when muscle cells die – so the concentration increases during a heart attack.
- Normal value for CK in men: ≤ 232 U/l
- Normal value for CK women: ≤ 215 U/l
In addition, the proportion of heart-specific creatine kinase in the total creatine kinase is measured. CK-MB (myocardial type) is the name of this creatine kinase, which only occurs in the heart muscle. A proportion of six to 20 percent is a sign of a heart attack. CK-MB normal value: ≤25 U/l.
LDH (Laktat-Dehydrogenase)
Elevated levels of this metabolic enzyme indicate cell damage in the body. The value is used for the late diagnosis of a heart attack. The standard values depend on age and gender and can therefore vary.
- Normal value in men: 135 to 225 U/l
- Normal value in women: 135 to 214 U/l
NBZ: Fasting blood sugar in diabetes
Diabetes mellitus is a chronic metabolic disease characterized by insulin resistance. Normally, the hormone insulin causes sugar (glucose) to enter the cells from the blood. In diabetics, sugar accumulates in the blood and the blood sugar level rises, which can be detected in the laboratory.
The fasting blood sugar is examined, i.e. the concentration of glucose in the blood twelve hours after the last food intake.
- Reference value for fasting blood glucose from capillary blood (fingerstick sample): ≤ 100 mg/dl
- Reference value for fasting blood sugar from the blood plasma (taken from the veins): ≥ 115 mg/dl ( blood sugar value is lower than that of capillary blood)
What do elevated laboratory values mean?
If an elevated blood sugar level is found in repeated tests, this is a sign of diabetes: in venous blood at a level greater than or equal to 126 mg/dl, in capillary blood at a level of over 110 mg/dl. Other tests can be used to diagnose diabetes: the sugar content is determined in the urine or an oral glucose tolerance test is carried out.
The HbA1c value (glycohemoglobin) is determined during treatment to determine how well the blood sugar level of a diabetic is controlled . This is red blood pigment (hemoglobin) to which a sugar molecule is bound. The HbA1c value is also referred to as blood sugar memory, because it allows conclusions to be drawn about how high the blood sugar concentration was on average in the last six to eight weeks.