Full Blood Examination + INR, APTT D-Dimer

Haemoglobin (Hb)

Haemoglobin is an iron-containing compound found in the red blood cells, which transports oxygen around the body. Measuring the concentration of haemoglobin in the blood can help diagnose anaemia, a condition caused by a deficiency of haemoglobin. Anaemia can arise due to:
too few red blood cells;
inadequate iron intake;
inadequate folate or vitamin B12 intake;
microscopic bleeding or other blood loss;
blood cell destruction;
a chronic illness; or
a defect in the haemoglobin molecule itself.
This measurement may also detect abnormally high concentrations of haemoglobin. This may occur in people with chronic lung disease, as an adaptation to high altitudes, or because of an abnormal increase in red cell production by the bone marrow (polycythaemia vera).

The normal haemoglobin level for adult males is 130-170 g/L, and 120-150 g/L for adult females.

Red cell count (RCC)

Red cell count is an estimation of the number of red blood cells per litre of blood.
Abnormally low numbers of red blood cells may indicate anaemia as a result of blood loss, bone marrow failure, malnutrition such as iron deficiency, over-hydration, or mechanical damage to red blood cells.
Abnormally high numbers of red blood cells may indicate congenital heart disease, some lung diseases, dehydration, kidney disease or polycythaemia vera.

The normal red cell count for adult males is 4.5-5.5 x 1012/L, and 3.8-4.8 x 1012/L for adult females.

Packed cell volume (PCV) or haematocrit (Hct)

Haematocrit is a measure of the percentage of red blood cells to the total blood volume.
A low haematocrit may indicate anaemia, blood loss, bone marrow failure, leukaemia, multiple myeloma, nutritional deficiency, over-hydration or rheumatoid arthritis.
A high haematocrit may indicate dehydration (for example, due to burns or diarrhoea), eclampsia (a serious condition that can occur during pregnancy) or polycythaemia vera.

The normal haematocrit range for adult males is 40-50 per cent, and 36-46 per cent for adult females.

Mean cell volume or mean corpuscular volume (MCV)

Mean cell volume is an estimate of the volume of red blood cells. It is useful for determining the type of anaemia a person might have.
A low MCV may indicate iron deficiency, chronic disease, pregnancy, anaemia due to blood cell destruction or bone marrow disorders.
A high MCV may indicate anaemia due to nutritional deficiencies, bone marrow abnormalities, liver disease, alcoholism, chronic lung disease, or therapy with certain medications.

The normal MCV range for adults is 83-101 fL.

Mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC)

These measures, also known as mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration, are further guides to the investigation of anaemia.
The MCH is the haemoglobin content of the average red cell. The MCHC is the average haemoglobin concentration in a given volume of packed red cells.
The MCH may be low in types of anaemia where the red blood cells are abnormally small, or high in other types of anaemia where the red blood cells are enlarged (for example, as a result of folic acid or vitamin B12 deficiency).
The MCHC is low in iron deficiency, blood loss, pregnancy and anaemias caused by chronic disease.

The normal MCH range for adults is 27-32 pg, and the normal MCHC range is 315-345 g/L.

White cell (leucocyte) count

White cell count estimates the total number of white blood cells per litre of blood.
An abnormal high or low white cell count can indicate many possible medical conditions and a leucocyte differential count, which provides numbers of the different types of white cells, is usually needed to help make any diagnosis.
Abnormally low numbers of white blood cells may indicate liver or spleen disorders, bone marrow disorders, or exposure to radiation or toxic substances.
Abnormally high levels of white blood cells may indicate infection, tissue damage, leukaemia, or inflammatory diseases.

The normal white cell count for adults is 4.0-10.0 x 109/L.

Leucocyte (white cell) differential count

Leucocyte differential count provides an estimate of the numbers of the 5 main types of white blood cells. These are: neutrophils; monocytes; lymphocytes; eosinophils; and basophils.
Each of the 5 types has a specific role in the body.
Neutrophils and monocytes protect the body against bacteria and eat up small particles of foreign matter.
Lymphocytes are involved in the immune process, producing antibodies against foreign organisms, protecting against viruses and fighting cancer.
Eosinophils kill parasites and are involved in allergic responses. High numbers of eosinophils may be associated with worm infections or exposure to substances that cause allergic reactions.
Basophils also take part in allergic responses and increased basophil production may be associated with bone marrow disorders or viral infection.

The normal ranges for the number of the different types of white cells in adults are:
Neutrophils: 2.0-7.0 x 109/L
Eosinophils: 0.02-0.5 x 109/L
Basophils: 0.05-0.1 x 109/L
Monocytes: 0.2-1.0 x 109/L
Lymphocytes: 1.0-3.0 x 109/L

Platelet count

Platelet count is an estimation of the number of platelets per litre of blood. Abnormally low numbers of platelets is known as thrombocytopenia, while an abnormally high level of platelets is known as thrombocytosis.
Platelet counts are often used to monitor medications such as heparin, which may cause low numbers of platelets, as well as medications that can have toxic effects on bone marrow. They may also be used to help diagnose problems associated with abnormal bleeding or bruising.

The normal platelet count for adults is 150-400 x 109/L.


The prothrombin time (PT) and its derived measures of prothrombin ratio (PR) and international normalized ratio (INR) are measures of the extrinsic pathway of coagulation. They are used to determine the clotting tendency of blood, in the measure of warfarin dosage, liver damage, and vitamin K status. The reference range for prothrombin time is usually around 12–15 seconds; the normal range for the INR is 0.8–1.2. PT measures factors II, V, VII, X and fibrinogen. It is used in conjunction with the activated partial thromboplastin time (aPTT) which measures the intrinsic pathway.

The prothrombin time is the time it takes plasma to clot after addition of tissue factor (obtained from animals). This measures the quality of the extrinsic pathway (as well as the common pathway) of coagulation.

The speed of the extrinsic pathway is greatly affected by levels of factor VII in the body. Factor VII has a short half-life and its synthesis requires vitamin K. The prothrombin time can be prolonged as a result of deficiencies in vitamin K, which can be caused by warfarin, malabsorption, or lack of intestinal colonization by bacteria (such as in newborns). In addition, poor factor VII synthesis (due to liver disease) or increased consumption (in disseminated intravascular coagulation) may prolong the PT.
A high INR level such as INR=5 indicates that there is a high chance of bleeding, whereas if the INR=0.5 then there is a high chance of having a clot. Normal range for a healthy person is 0.9–1.3, and for people on warfarin therapy, 2.0–3.0, although the target INR may be higher in particular situations, such as for those with a mechanical heart valve, or bridging warfarin with a low-molecular weight heparin (such as enoxaparin) perioperatively.

APTT - A phlebotomist collects blood samples in vacu-tubes with oxalate or citrate to arrest coagulation by binding calcium. The specimen is then delivered to the laboratory. In order to activate the intrinsic pathway, phospholipid, an activator (such as silica, celite, kaolin, ellagic acid), and calcium (to reverse the anticoagulant effect of the oxalate) are mixed into the plasma sample . The time is measured until a thrombus (clot) forms. This testing is performed by a medical technologist.

A positive D-dimer indicates the presence of an abnormally high level of fibrin degradation products in your body. It tells your doctor that there has been significant clot (thrombus) formation and breakdown in the body, but it does not tell the location or cause.