Health screening Blood Testing Guide

    • White Blood Cell Count - The WBC (white blood cell) count is a common test within a health assessment and is a measure of your body's ability to fight infection. A normal WBC level can be interpreted as a sign that the first line of defence against invasion by bacteria or other disease causing organisms is intact and functioning. Moderately elevated white cell counts are a sign of acute infection, while very high counts of abnormal white cells are encountered with leukaemia (a relatively rare form of blood cancer). 

 

    • Red Blood Cell Count - The RBC (red blood cell) count is the number of red blood cells present. It can vary considerably, and a marginally low or high health screening reading may not imply a problem. Significantly reduced numbers within any health check can be associated with anaemia (a deficiency in red cell production, or excessive loss of blood), and very high numbers are seen in polycythaemia (a condition which can be caused by smoking, living at altitude or just because the bone marrow makes too many red cells).

 

    • Protein - Proteins are indespensible as transporters of many other essential molecules around the body. Within your health screening high levels can be seen in disorders of over production such as myeloma, low levels can be found in conditions of failure to produce protein (eg liver disease) or excessive loss from the body (such as malnutrition or kidney disease) 

 

    • Globulin - Globulins are another category of protein which form the basis of antibodies (produced by Lymphocytes). Low levels within a health screening (hypogammaglobulinaemia) can be seen in immune deficiency or excessive loss from the kidneys. Higher levels may be a sign of gammaglobulinopathy or myeloma - a state of excessive production of globulin by some of the lymphocytes. 

 

    • GGT - GGT (gamma GT) is a liver enzyme. High levels are most commonly encountered when alcohol has been drunk at higher than recommended levels in the preceding few weeks. Some medication can lead to higher levels of this enzyme also.

 

    • Cholesterol, total. - Cholesterol is a form of fat (lipid) bound to protein known as a lipoprotein, and is an essential component of all cell membranes (boundaries) - but an excess of it during a health screening is linked to an increased risk of heart and blood vessel disease. The total figure is useful, but it is more helpful to know the levels of the two parts which make up the bulk of the cholesterol molecule - HDL and LDL.

 

    • Triglycerides - Triglycerides are a category of fat found in the blood. Triglycerides effectively store energy for later use by the body. High triglyceride levels within a health screening are associated with pancreatitis, and possibly heart disease and strokes. Some medication can cause the level to rise, as can poorly controlled diabetes.

 

    • HDL Cholesterol - HDL (high density liporoprotein) is the component of cholesterol that is associated with good health, and high levels within a health sceren are linked to reduced risk of heart and blood vessel disease.

 

    • Cholesterol/HDL ratio - The cholesterol/HDL ratio demonstrates the proprtion of HDL compared to total cholesterol present - the closer to 4.5 mmol/L (or 20% if expressed as %HDL of total cholesterol) this figure is within a health screening, the lower the overall risk of heart or blood vessel disease from cholesterol induced damage.

 

    • LDL Cholesterol - LDL (low density lipoprotein) is the component of cholesterol that is associated with higher risk of heart and blood vessel disease. The ideal level within a health screening is below 2.5 mmol/L

 

    • IRON - The serum iron level is a measure of the circulating iron in the blood. It tells us (along with TIBC/UIBC, transferrin and ferritin) the state of the body's iron reserves. An excess in a health screening can indicate disorders of iron storage (such as haemochromatosis), while low levels may indicate (along with changes in TIBC/UIBC, transferrin saturation and ferritin) iron deficiency.

 

    • TIBC - The TIBC (total iron binding capacity) is a measure of the body's ability to store iron. The higher the level within a health screening, the less iron there is in reserve. This test can be used to detect iron deficiency, and also conditions of iron excess (such as haemochromatosis). It is an equivalent test to UIBC.

 

    • Transferrin Saturation - Transferrin saturation, like TIBC/UIBC, is a measure of iron storage. The higher the level within a health screening, the greater the amount of iron stored.  This test can be used to detect iron deficiency, and also conditions of iron excess (such as haemochromatosis)

 

    • Ferritin is a protein found in the blood which carries iron. Like TIBC/UIBC, and transferrin saturation, it can tell us how much iron is stored in the body. The higher the level within a health screening, the greater the amount of iron stored.  This test can be used to detect iron deficiency, and also conditions of iron excess (such as haemochromatosis). Ferritin can also be raised if inflammation is present in the body somewhere.

 

    • TSH - The TSH (thyroid stimulating hormone) is a hormone manufactured in the pituitary gland (found in the brain). It s role is to stimulate thyroxine production in the thyroid gland (found in the neck). A high level within a health screening is associated with an underactive thyroid gland (hypothyroidism) and a low level is found if the thyroid gland is over-active (hyperthyroidism). Changes in the TSH  level alone can indicate underlying thyroid problems even if the thyroxine levels are normal.

 

    • Free T4 - FT4 (free thyroxine) is the active form of thyroxine, released from the thyroid gland in the neck. Its role is to control metabolism - release of energy from all cells of the body. A lack of thyroxine leads to, for example, tiredness and weight gain, whereas an excess will lead to weight loss, rapid heart rate and anxiety. It is generally believed that this level (FT4) is the most reliable indicator of thyroid status - ie whether the gland is over-active (hyperthyroidism) or underactive (hypothyroidism).

 

    • LDH - LDH (lactate dehydrogenase) is found in almost all tissues but only a small amount of it is detectable in the blood. It usually stays within the cells. When cells are damaged or destroyed, LDH enters the blood. LDH within a health screening is used as a general marker of injury to cells, and many cells can release it to varying degrees.  A total LDH level is an overall measurement of five different LDH isoenzymes (or subgroups). A rise in the level may indicate a problem with cell damage somewhere in the body. A low level is probably of little significance.

 

    • Uric Acid - Uric acid is a normal waste product of protein breakdown in the body. Low levels within a health screening are generally of no concern, but high levels can lead to gout - an acutely painful inflammation of the joints. High uric acid can also be associated with some medication (especially diuretics), diet or possibly be of genetic origin.

 

    • Ferritin is a protein found in the blood which carries iron. Like TIBC/UIBC, and transferrin saturation, it can tell us how much iron is stored in the body. The higher the level within a health screening, the greater the amount of iron stored.  This test can be used to detect iron deficiency, and also conditions of iron excess (such as haemochromatosis). Ferritin can also be raised if inflammation is present in the body somewhere.

 

    • Vitamin D is an important vitamin, essential for good bone helath. It is manufactured in the skin through sunlight exposure, and is found in a number of foods. Prolonged Vitamin D lack can cause osteomalacia, a disease which causes severe structural deformities to the skeleton. Lower level Vitamin D deficiency can lead to a number of non specific symptoms, including chronic pain, weak bones, frequent infections  depression and fatigue. It has been estimated that between 50-70% of people living in the northern Europe (where daylight length reduces your chances of receiving adequate sunlight in the winter) are deficient in this vitamin by March each year which is why health screening for this important vitamin is essential.

 

    • Vitamin B12 is an important vitamin, essential for the normal functioning of many body processes. Deficiency can lead to anaemia (poor quality red blood cells) and neurological (nerve) disorders. It is most abundant in meat products so vegetarians are more vulnerable to deficiency of this vitamin. Pernicious anaemia develops if uptake of vitamin B12 into the blood from the gut is absent or severely impaired, and even if a diet rich in the vitamin is taken, deficiency will occur if this disease is present. Recent evidence suggests that mild deficiency is probably more common than previously thought. Mild deficiency may explain the presence of fatigue and a host of other limiting symptoms which is why we have included it within the PLUS V and PLUS X health screening profiles.

 

    • Sodium is an essential electrolyte involved in a number of bodily functions. The kidneys regulate its level in the body.  High or low levels can be seen in a number of diseases, and the level can be influenced either way by prescribed medication (eg diuretics can cause a drop in sodium).

 

    • Potassium is another essential electrolyte, whose level in the blood is largely determnined by the kidneys.  Like sodium, screening for low or high levels of potassium can indicate a problem with health due to disease or inappropriate medication. Potassium levels are very sensitive to storage - if there is any delay in testing, the level is often higher than would otherwise be expected. Normally, it is readily apparent if the rise is due to storage change as other test results will usually be normal.

 

    • Urea, like creatinine, is a waste product of normal bodily function - its level in the blood is controlled entirely by the kidneys. Rising levels of Urea that are detected in your pathology results may indicate kidney disease or damage, although small rises may also be a sign of dehydration. Low levels are of no concern.

 

    • Creatinine, like urea, is a waste product of bodily processes. The kidneys control its elimination from the blood. A rise in creatinine within a health screening, especially if urea levels are also high, will usually mean there is a degree of compromise of the kidneys. Small rises can be a sign of dehydration. Low levels are of no concern.

 

  • Glucose - Glucose is the form of sugar that is transported around the body in blood to provide energy for all bodily functions. A very common blood test, but an essential part of any health screening, high levels are diagnostic of diabetes mellitus, a state in which the body is unable to handle glucose adequately. Low levels can occur in healthy individuals on occasion, but if sustained, a low level of glucose may indicate an underlying problem with how sugar levels are maintained by the body. As we recommend that you fast for your health screening this will be reported as a FASTING blood glucose level.