Blood test: blood test

The blood test (also called a blood test) is one of the most useful tools of the doctor.

During the examination, the doctor orders blood tests to obtain the entire blood count and information on proteins, cholesterol, etc.

The blood count contains all values regarding:

  • white blood cells (leukocytes, lymphocytes, etc.),
  • red blood cells,
  • Platelet
  • BKS.


Stay sober, smoking and coffee

For blood sampling, it is only necessary to observe a fasting period of at least 8-12 hours for the following examinations:

  • Blood sugar
  • Insulin

There is disagreement in the following investigations. However, in order to be able to compare the results with other studies, it is advisable to be sober:

  • Cholesterol
  • Lipase
  • Triglycerides (14 hours)

In addition, the following should be avoided:

Drinking water is allowed.

Below are the explanations for the symbols and values used in blood tests.

Proteins in the blood test

The proteins in the blood are divided into 5 subgroups:

  1. Albumins
  2. Alpha-1 globulins
  3. Alpha-2 globulins
  4. Beta globulins
  5. Gamma globulins
Total protein
The normal values of total proteins are between 6 and 8 g/dl.
  • Elevated levels of total protein (hyperproteinemia) are less common and could indicate severe dehydration.
  • Low levels of total protein (hypoproteinemia) can be a sign of severe liver disease (liver failure).

Normal values: from 3.9 to 5.0 g/dl
A protein produced in the liver. The albumin levels may be an indication of diseases of:

  • Liver
  • Kidney.

The normal values of alpha-1 globulins are 0.2 – 0.4 g/dl.
The values are increased in strong inflammatory processes, such as:

  • Infectious diseases
  • chronic inflammatory diseases and autoimmune disorders (lupusrheumatoid arthritis, etc.),
  • Heart attack
  • Neoplasia.

Decreased values can be caused by the following:

  • severe liver disease,
  • congenital emphysema (rare hereditary disease affecting the lungs),
  • Kidney disease.

The normal values of alpha-2-globulins are 0.4 – 0.8 g/dl.
Elevated alpha-2-globulin levels can be caused by:

  • acute bacterial inflammation,
  • Traumas
  • surgical interventions,
  • Heart attack
  • neoplasms,
  • Down’s syndrome.

Decreased alpha-2 globulin levels can be caused by:

  • viral hepatitis,
  • inflammation of the pancreas (pancreatitis),
  • Diabetes
  • Hemolysis (dissolution of red blood cells).

The normal values of beta-globulins are 0.6 – 1 g/dl.
Elevated beta-globulin levels may be an indication of:

  • iron deficiency anemia,
  • nephrotic syndrome,
  • hypercholesterolemia (too high cholesterol levels in the blood),
  • liver and biliary tract diseases,
  • Pregnancy.

Low levels are a sign of:

Normal values: from 0.77 to 1.64 g/dl
Decreased gamma globulins may be caused by:

Increased gamma globulins can be caused by:

A/G (albumin/globulin quotient) Normal relationship: slightly more than 1 (1.2 – 1.7)
in favor of albumin.
There are two types of protein in the blood – albumin and globulin. The A/G test compares the levels of these two substances.

Blood test for electrolytes and mineral salts


Normal values: from 2.4 to 4.1 mg/dl
Phosphorus plays an important role in bone health and is bound to calcium levels.
Elevated phosphorus levels may indicate that:

  • kidney problems or problems of the parathyroid glands,
  • alcohol abuse,
  • a long intake of antacids,
  • too many diuretics or vitamin D,
  • Malnutrition.

Normal values: from 3.7 to 5.2 mmol/l
This mineral is essential:

  • for the transmission of nervous impulses,
  • to maintain muscle functions,
  • for the regulation of the heartbeat.

Low potassium levels
Low potassium levels can be caused by:

Elevated potassium levels
High potassium is caused by:

Normal values: from 135 to 145 mmol/l
It is an electrolyte needed to:

  • transmission of nerve impulses,
  • Muscle contraction.

Elevated sodium levels
Elevated sodium may indicate that:

  • Dehydration
  • prolonged intake of corticosteroids,
  • Cushing’s syndrome,
  • kidney disorders,
  • diabetes mellitus and insipidus,
  • Excess of salt in the diet.

Low sodium levels
Decreased sodium 
is caused by:

  • diuretic drugs, barbiturates, opiates,
  • Diarrhoea
  • insufficiency of the adrenal glands (less common),
  • excessive fluid intake,
  • kidney diseases,
  • Heart failure
  • Cirrhosis.

Normal values: from 9.0 to 10.5 mg/dl (older people are generally slightly lower)

Elevated calcium levels
Too much calcium in the blood could indicate that:

  • kidney problems,
  • hyperthyroidism,
  • Hyperparathyroidism: high parathyroid hormone levels,
  • some cancers, including lymphoma, lung and ovarian cancer,
  • Excess of vitamin D.

Low calcium levels
Low calcium in the blood is a possible indication of:

  • Hypoparathyroidism: low parathyroid hormone levels,
  • diet low in calcium,
  • vitamin D deficiency,
  • inflammation of the pancreas (pancreatitis),
  • Kidney disease.

50% of the magnesium contained in the body is found in the bones.
A small proportion is contained in the blood.
Magnesium is important for the functioning of nerves and muscles.
Normal values of magnesium: 1.41 – 1.85 mmol/l

Increased magnesium levels
Elevated magnesium levels can be caused by:

  • Renal failure
  • Antacids or laxatives.

Low magnesium levels
Low magnesium levels are caused by:

  • Alkoholmissbrauch,
  • anhaltender Durchfall,
  • hoher Schilddrüsenhormonspiegel,
  • harntreibende Arzneimittel.

Normalwerte: von 50 bis 150 µg/dl

Erhöhte Zinkwerte
Erhöhte Zinkwerte können ein Hinweis sein auf:

  • Neutropenie,
  • Anämie.

Niedrige Zinkwerte
Zu den Ursachen für Zinkmangel zählen:

  1. Mangelernährung,
  2. AIDS,
  3. Leukämie,
  4. Lymphom.

Einige Anzeichen, die durch verursacht Zinkmangel werden:

  • Altered sense of taste
  • Striae (stretch marks)
  • Acne
  • White spots on the nails
  • Growth retardation – especially in children
  • Hair loss
  • Anorexia
  • Slow healing of skin injuries
  • Chronic diarrhea
  • Weakened immune system
  • Nocturnal vision loss
  • Skin dryness
  • Irregular monthly cycles
  • Adolescent male impotence
  • Joint pain in young people (knee and hip)

Blood test for iron

Serum iron
It is the value that indicates the concentration of iron in the blood.
Normal values:

  • Men from 65 to 170 μg/dl
  • Women from 50 to 170 μg/dl

Values raised far beyond the norm may indicate that:

  • Hemochromatosis
  • Hemolysis
  • Hemolytic anemia
  • Hemosiderosis
  • Hepatic necrosis
  • Hepatitis
  • Iron poisoning
  • Frequent blood transfusions
  • Pharmaceuticals (methyldopa, chloramphenicol)

Values below the standard may indicate the following:

  • Gastrointestinal blood loss
  • Heavy menstrual periods
  • Decreased absorption of iron
  • Too little iron in the diet
  • Pregnancy
  • Anaemia
  • Lack of vitamin B-12 or B-6
  • Diabetes

Ferritin is a protein found in cells that contains iron.
Normal values:

  • 12-300 ng/ml in men
  • 12-150 ng/ml in women

Low ferritin levels are a possible indication of:

  • Malnutrition
  • sideropenic anemia,
  • Vitamin C deficiency.

High values may indicate that:

Transferrin is a protein of the blood that is responsible for transporting iron to:

  • Liver
  • Spleen
  • Bone marrow.

Transferrin saturation:

  • < 20 % means iron deficiency,
  • > 20% means excess iron.

The reference interval of saturation varies with age:

  • Adults: 20 – 50 %
  • Children: > 16 %

Blood test for heart and metabolism

Fasting sugar
Normal values: from 70 to 110 mg/dl for an average adult
Blood glucose levels vary depending on:

  • ingested food,
  • stress level,
  • medication taken,
  • Daytime.

High glucose levels may indicate that:

Low glucose levels can be caused by:

  • liver disorders,
  • adrenal insufficiency,
  • too much insulin use.

Creatine phosphokinase (CPK)

CPK is a very useful enzyme for diagnosing:

  • Heart disease
  • Skeletal muscle diseases.

Normal values of the CPK are:

  1. Skeletal muscle specific (CK-MM) up to 50 mU/ml
  2. Cardiac muscle specific (CK-MB) up to 10 mU/ml

Higher than normal are the values of creatine phosphokinase:

  • after a heart attack (3-4 hours),
  • after surgery.

If the CPK value is elevated without heart problems, skeletal muscle problems are likely to be present, for example:

  • pain in the legs,
  • muscle lesions or contractures,
  • Diseases of the muscles (dystophy).

These are fission products of fibrin.
This test is used to rule out a blood clot, which may be the trigger for:

Normal values: below 500 ng/ml
An elevated D-dimer can be caused by many different diseases:

Not due to illness:

  1. Age (healthy elderly)
  2. Cigarette smoking
  3. Postoperative
  4. Pregnancy and the postpartum period
  5. Race (for example, African-American)


  1. Acute coronary syndrome
  2. Upper gastrointestinal bleeding
  3. Arterial or venous embolism
  4. Atrial fibrillation
  5. Infections
  6. Cancer
  7. Preeclampsia
  8. Sickle cell anemia (hemolytic crises)
  9. Stroke
  10. Aneurysm
  11. Subarachnoid hemorrhage (cerebral)
  12. Subdural hematoma
  13. Superficial thrombophlebitis
  14. Trauma
  15. Inflammatory bowel disease (ulcerative colitis and Crohn’s disease)
  16. Chronic inflammatory disease (for example, rheumatoid arthritis)

Vitamin D
Normal values: 30 to 74 ng/ml
Doctors often recommend a vitamin D supplement because deficiency symptoms occur very frequently.

Excessive intake of vitamin D may lead to:

  • Poisoning
  • excessive calcium levels in the blood (hypercalcaemia),
  • Damage to the kidneys and renal insufficiency.

Vitamin D deficiency is a risk factor for various disorders such as:

Blood test for cholesterol and triglycerides

Total cholesterol

  • Healthy below 200 mg/dl (below 5.18 mmol/l)
  • Borderline (borderline) between 200 and 239 mg/dl (from 5.2 to 6.2 mmol/l)
  • Increased above 240 mg/dl (above 6.2 mmol/l)

This test measures the (“good”) cholesterol level HDL and the (“bad”) LDL.

High cholesterol can be caused by:

  • Overweight
  • Hypothyroidism
  • Pancreatitis
  • Contraceptive pill
  • Nephrotic syndrome
  • Diabetes
  • Liver diseases, such as primary biliary cirrhosis and hepatitis
  • Cushing’s disease
  • Systemic lupus erythematosus

Normal values: from 40 to 160 mg/dl
If these fats are present in excess in the blood, they can promote heart diseases such as:

HDL (“good”) cholesterol
General rule:

  • Very good over 60 mg/dl
  • Good from 50 to 60 mg/dl
  • Deficient below 40 mg/dl for men; less than 50 mg/dl for women

The “good” cholesterol or HDL protects against heart disease. Low levels are risk factors for heart disease.

LDL (“bad”) cholesterol

  • Optimal below 100 mg/dl
  • Almost optimally good from 100 to 129 mg/dl
  • Borderline between 130 and 159 mg/dl
  • High between 160 and 189 mg/dl
  • Very high above 189 mg/dl

The “bad” or LDL cholesterol is a substance that is deposited in arteries. It therefore causes arteriosclerosis and can cause:

  • Thrombus
  • Embolus.

Total cholesterol/HDL
guideline of the American Heart Association:

Normal values:

  • Men: < 5
  • Women: < 4.5

– Optimal ratio: 3.5 to 1
– Healthy ratio: 5 to 1 or less
This ratio is another mode to control the risks of heart disease.

Tumor markers in the blood test

PSA is a prostate-specific antigen and is used to detect the first signs of prostate cancer.
Normal values are:

  1. People between 50 and 59 years of age should have less than 3 ng/ml.
  2. Between 60 and 69 years, the values should be below 4 ng/ml.
  3. Over 70 years, the values should be less than 5 ng/ml.

An elevated PSA is an indication of:

CEA (carcinoembryonic antigen)
This protein is used to diagnose neoplasia of the digestive tract and especially a tumor in the intestine.
Normal values:

  • in men below 5 ng/ml,
  • on the other hand, less than 7.5ng/ml in women.

If the values exceed 25 ng/ml, it is likely that the patient has a colorectal tumor.

Blood test during pregnancy

Beta HCG
It is a very important pregnancy hormone for the development of the child, because it stimulates the production of a high amount of progesterone. The normal values in NOT pregnant women are lower than 5 IU/l.

Blood test for ANA antibodies

Antinuclear antibodies are a group of antibodies that have the ability to attack structures of the cell nucleus. The nucleus of a cell contains genetically defined material such as DNA.
An ANA test helps diagnose some autoimmune diseases.

Positive ANA test result
Antinuclear antibodies are found not only in patients with various autoimmune diseases.

Antinuclear antibodies are also found in patients with:

  • Infections
  • Cancer
  • Lung disease
  • gastrointestinal disorders.

In addition, they are detected in the elderly.
Antinuclear antibodies are also found in about 5% of the healthy population.

Statistically, the percentage frequency of a positive test result for ANA is in the following cases:

  • Systemic lupus erythematosus – more than 95%
  • Scleroderma – 60-90%
  • Rheumatoid arthritis – 25-30%
  • Sjögren’s syndrome – 40-70%
  • Juvenile arthritis – 15-30%

Other blood tests

Gliadin Antibody (AGA)
These antibodies, together with endomysium antibodies (EMA), are used to diagnose celiac disease.
AGA values:

  • From 0 to 8 negative
  • From 8 to 12 borderline
  • Over 12 positive

Homocysteine (Hcy)
Normal values between 5 and 12 micromoles.
It is an amino acid that damages the vascular walls and promotes the development of:

Homocysteine leads to an increased formation of free radicals.
High homocysteine levels can be caused by:

By taking folic acid, the homocysteine level can be lowered.

Uric acid
Normal values: from 3.5 to 7.2 milligrams of uric acid per deciliter of blood (mg/dl).
This substance is excreted in the urine.
Decreased uric acid levels are less common and do not have to worry.
Increased uric acid is associated with:

  • Gout
  • Arthritis
  • kidney problems,
  • taking diuretic drugs.

The carbonic acid content reflects the acidity of the blood.
2 is a gaseous substance and metabolic waste product.
Normal values 20 – 29 mmol/l
Decreased CO
2 can be caused by:

  • Kidney disease
  • severe infections.

Increased CO2 is caused by:

  • Pneumonia
  • Emphysema
  • Chronic obstructive pulmonary disease (COPD).

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