Notes to 18KS


This booklet on Pathlab Blood Screen is not meant to be comprehensive. It provides some relevant information on the tests done and should make interesting reading. FOR FURTHER INFORMATION, PLEASE CONSULT YOUR DOCTOR.

For each test, you are supplied with your result and the normal range of that test. The normal range of a test will cover 95% of normal people. Thus 5% of the results can be slightly above or below the normal range and occur in normal people. The value of the test will fluctuate from time to time but always within the normal range if the person is not sick.



High blood cholesterol is due either to excessive intake of cholesterol rich food or increased production by the liver. High blood cholesterol leads to increased deposition in the wall of blood vessel (atherosclerosis) resulting in narrowing and subsequently blockage. When that happens in the heart, a heart attack results and when it happens in the brain, the result is a stroke. Cholesterol levels above 200 mg/dl is associated with increased risk of atherosclerosis and this risk rises with increasing levels. Low cholesterol level is seen in thyrotoxicosis and liver disease.


This type of cholesterol is the “good cholesterol” as it helps to remove cholesterol from the tissue and transport it to the liver for excretion. Therefore for HDL cholesterol,the higher the level the better it is for the body. High level of HDL cholesterol is associated with women before menopause because of the female hormone. All can increase their levels by doing regular exercise (30 minutes 3 times a week). Smoking of cigarettes will lower the level of HDL cholesterol. HDL cholesterol is produced by the liver.


This ratio evaluates the effect of cholesterol on atherosclerosis and coronary risk.The lower the ratio, the lower will be the risk. When the ratio is high, examine the total cholesterol and HDL-cholesterol values to see if one or both are at fault.


This is the “bad cholesterol” as it helps in the deposition of cholesterol in the wall of blood vessels. High levels of LDL-cholesterol is a major risk factor for atherosclerosis.LDL-cholesterol levels can be lowered by reducing the intake of cholesterol rich food and regular exercise.


This type of fat is also found in the fat tissue of the body and is a major source of energy. Excess calories from consuming too much sugar, starchy and oily food and lack of exercise are converted to triglycerides resulting in high blood levels and obesity.Triglycerides are also deposited in the wall of blood vessels and high blood levels are associated with increased atherosclerosis and coronary risk.



This is a yellow pigment produced by the breakdown of red blood cells and excreted by the liver. Blood levels above 2 mg/dl will lead to jaundice (yellowness of the eyes and skin). High blood levels are associated with liver diseases and blood disorders.


This is an enzyme produced by bone and liver cells. High levels are seen in some bone disorders and liver disorders like obstructive jaundice, gall stones and cancer. In these conditions other abnormal blood tests are also present as well. Levels up to 3times the adult level are seen in children when they are rapidly gaining height and is normal.


This enzyme is present in high concentration in liver cells. When liver cells die, SGPT is released into the blood resulting in high blood levels. The level is related to the amount of liver cells involved. In acute hepatitis, SGPT is usually more than 10times the normal range.


This enzyme is present in cells of many organs like liver, heart, skeletal muscle and blood cells. High blood levels are associated with cell destruction in the organs like acute myocardial infarction (heart attack) and hepatitis.


This liver enzyme is particularly useful in detecting damage to the liver due to alcohol and drugs. Heavy drinkers who have liver damage will have high blood levels.


This is the sum total of albumin and globulin. Abnormal blood levels may be due to increase in albumin, globulin or both.


This protein is produced by the liver. Low levels are seen in severe liver disease due to reduced production or kidney disease due to loss of albumin in the urine.


This complex group of proteins have many diverse functions. One important component is immunoglobulins which are antibodies used to fight infections. High levels indicate the presence of chronic illnesses or infections and very high levels are seen in multiple myeloma.


HBs Ag is a part of the capsule of the hepatitis B virus and if positive represent hepatitis B infection. If the liver enzymes are normal, the person is a carrier of hepatitis B. If the enzymes are high for months, that person is suffering from chronic hepatitis B. Both groups have a higher risk of liver cancer than the normal population.


A person who recovers completely from a hepatitis B infection or had a successful hepatitis B immunization will have HBs antibody. The level of HBs antibody will decrease with time. Those who acquire the HBs antibody through immunization will require a booster dose if the level falls below 10 mIU/ml.


Hepatitis A is acquired by taking food or drinks which are contaminated with faecal matter from an infected person. The majority of patients will recover and the disease does not become chronic as in hepatitis B. Those who had recovered will be positive for HAV antibody and be protected from future infection with hepatitis A.



Blood urea is the major “end-product” of protein metabolism and is excreted from the body by the kidneys. Levels slightly above normal are seen in persons on a high protein diet or after prolong fasting. High levels are seen in kidney diseases.


Blood creatinine is produced by the normal turnover of muscles and excreted by the kidneys. It is influenced by the muscle mass of a person but not by dietary factors.High levels are seen in kidney diseases.

ELECTROLYTES (Bicarbonate, Potassium, Sodium & Chloride)

Blood levels of the electrolytes depends on the balance between intake and production on the one hand and excretion by the kidney on the other. Abnormal values are usually seen in patients with kidney disorders. Medication for hypertension and heart diseases can effect the electrolyte levels.



Blood glucose level is controlled by the hormone Insulin and levels above the normal range indicate the presence of diabetes mellitus. An additional test called the Glucose Tolerance Test (GTT) is indicated to confirm the diagnosis and assess the severity.


This hormone is produced by the thyroid gland and regulates the metabolic processes of the body. High levels are seen in the disease Hyperthyroidism. Patients with this condition will experience weight loss, tremor of hands, anxiety and increased sweating. Hypothyroidism (low levels) is due to reduced production by the gland and results in slowing down of metabolism with mental dullness, physical slowness and weight gain. The gland can be enlarged due to cysts or cancer and the level of Free T4 may or may not be affected. BONE & JOINT PROFILE


Calcium is necessary for strong bones and teeth, normal clotting of blood and muscle contraction. Low levels are due poor dietary intake and a number of medical conditions. Milk and calcium tablets are good sources of calcium.


Phosphate is primarily involved in bone metabolism. High levels are seen in normal children with active bone growth. Patients with kidney failure or bone disease also have high phosphate level.


Uric acid is formed from the metabolism of nucleic acid. Blood levels depend on the balance between dietary intake and synthesis by the cells and excretion by the kidney. High uric acid levels will lead to gout, urinary stones and kidney disease. Treatment of high uric acid should include reducing intake of high protein diet (eg. internal organs and fish roe), soya bean products and alcohol.


Rheumatoid arthritis is a severe form of joint disease affecting mainly the joints of the hands and feet. The diagnosis of rheumatoid arthritis depends on the presence of symptoms and signs of joint disease and a positive R. A. Factor test. A small percentage of patients may be negative for the test and the test may be positive in some diseases other than rheumatoid arthritis.


Cancer occurs when cells in the body escape the control of the body and begin to multiple and grow. They grow very quickly and to very large size. In the process,they destroy normal cells, block the function of normal organs, cause pain and bleeding and finally kills the person. Any cell in the body can become cancerous and some things can increase the chance of the cell becoming cancerous. Examples are smoking in causing lung cancer and hepatitis B in causing liver cancer. Although cancer cells grow quickly, it still takes many months for the original cancer cell to grow to a large size and finally kill the person. Early detection of cancer means the cancer is detected when it is still small or it has not spread to the rest of the body. Surgery can remove a small cancer completely and produce a cure. In all cases, early detection means early treatment and better chance of survival.

Signs and symptoms of cancer
  1. As the cancer grow in size, it will produce a lump or cause the organ in which the cancer cells are growing to enlarge. In all cases, the lump or organ will get bigger and bigger.
  2. When the cancer cells press or invade normal tissue, there will be pain and the pain will get worse and worse.
  3. Cancer cells grow rapidly and use up nutrients meant for normal cells. This result in weight loss, a decrease in the number of normal cells and abnormal functioning of normal cells.
  4. When cancer occurs in a hollow organ like the stomach and intestine, it will grow into the lumen of the organ causing obstruction and bleeding. In the stomach, it will cause vomiting while in the intestine, it will lead to constipation.
  5. Some types of cells produce abnormal substances or normal substances in large amounts when they become cancerous. These substances are called cancer markers and they help in the identification, early detection and monitoring of the treatment of the cancer.
  6. The detection of cancer depends on how quickly the cancer causes signs and symptoms or makes itself known through the production of cancer markers. In general, cancers in organs within the abdomen are usually detected late because they can grow to a large size before they are noticed.


Every year, more and more cancer markers are discovered. In order to use and benefit from cancer markers, we must bear in mind the following.
  1. Not all cancer cells produce cancer markers. Therefore, the absence of cancer markers or normal levels of cancer markers cannot exclude the presence of cancers.
  2. There is at present no one cancer marker for all cancers. As cancer markers are specific to the type of cells and these cells are present in different organs, the same cancer marker can be present in cancers of these different organs.
  3. When a cancer marker is present at a very high level, it is almost certain that a cancer is present in the body.
  4. As cancer markers can be produced by cells when they are affected by conditions other than cancer, slight increase in the level of cancer markers do not necessary mean the presence of cancer.
  5. As cancer cells grow rapidly and continuously, the amount of cancer markers produced will increase and increase very rapidly. By monitoring the increase in the level of cancer markers over time, cancers can be separated from non-cancerous conditions producing a slight increase in cancer markers.
  6. Cancer markers are very useful in monitoring the effective treatment of cancer that produce cancer markers. The level of the cancer marker is determined before treatment and repeated at each stage of the treatment.
Some common cancer markers
Main organ: liver
Other organs: testis, ovary

Beta HCG
Main organ: choriocarcinoma
Other organs: testis, ovary

CA 15.3
Main organ: breast
CA 19.9
Main organ: pancreas
Other organs: intestine, stomach

CA 125
Main organs: ovary
Other organs: liver, lung, intestine

Carcinoembryonic Antigen (CEA)
Main organ: intestine
Other organs: stomach, pancreas, breast, bronchi

Main organ: nasopharynx

Helicobacter pylori antibody
Main organ: stomach

Prostatic Specific Antigen (PSA)
Main organ: prostate



VDRL test is a very sensitive test for detecting syphilis infection (one of the many venereal disease). However, positive tests are also encountered in some patients with common viral infections and autoimmune diseases. If the VDRL test is positive, the confirmatory test, TPHA must be performed. Only when both the tests are positive isthe diagnosis of syphilis confirmed.



Haemoglobin, the red pigment in the red blood cells is essential for the transport of oxygen to the tissue. If the level is below the normal range, the person is anaemic,looks pale and tires easily. Severe anaemia can lead to heart failure. Anaemia can be due to (a) decreased production of normal red blood cells (b) lack of essential nutrients like iron and (c) hereditary disorders like thalassemia. Each of these will have features which can help the doctor make the diagnosis. Additional tests are needed to confirm the diagnosis.


White blood cells acts as soldiers and scavengers in the body and are mobilised to fight against infection or remove waste debris. Different white blood cells play different roles; neutrophils against bacterial infection, lymphocytes against viral infection, monocytes act as scavengers and eosinophils against parasitic infections and allergic conditions. White blood cells will change in numbers and types of cells in response to the infective agent. Sometimes abnormal cells called atypical mononuclear cells(AMC) are also present. When leukemia (cancer of blood cells) occur, the number of white blood cells will be markedly increased and immature cells called blasts will replace the normal cells. When no mention is made of these cells in the report, theyare not detected.


Platelets are small cytoplasmic fragments of the megakaryocytes which are found in the bone marrow. They play a major role in normal blood clotting and bleeding prevention. Platelet count below 50,000/cmm is associated with prolonged clotting and bleeding times, bleeding into the skin and tissue and is seen in patients with leukemia, ITP and dengue hemorrhagic fever.


Blood is made up of the cellular component and the liquid component called plasma.If blood is left to stand, the cellular component will sediment and the amount it settles in 1 hour is the ESR. Many factors can influence the ESR. In general, the higher the ESR, the higher the chance of a chronic disease. Investigations are then needed to find the disease.


A thin smear is made of the blood, stained with special dye and examined under the microscope. The normal red blood cells are described as normochromic (normal colour) and normocytic (normal size). Any variations from the normal will be duly described.The significance of abnormal cells has to be interpreted in conjunction with the rest of the blood tests. No early cells seen means that there is no leukemia.


ABO and Rhesus are the two commonly used method of typing the blood. Under the ABO system, the blood can be A, B, AB or O. The percentage of the different ABO groups in the population is approximately A(23%), B(23%), AB(5%) and O(49%).Rhesus grouping is reported as Positive or Negative. Rhesus grouping becomes important when a Rhesus Negative woman becomes pregnant with a Rhesus Positive baby. But with modern medical treatment, this is not a problem provided the diagnosis is made early. Blood grouping is important when a person requires a blood transfusion. There is no such thing as a “bad” blood group.


Urine is produced by the kidneys from blood flowing through them. It therefore reflects conditions in the blood, kidneys and urinary tract. The findings in the urine is also influenced by the things we eat and drink.


The urine can be acidic or alkaline depending on the food we take and the time of the day the sample is taken. The types of crystals detected in the urine will vary with the reaction of the urine.


Glucose in the urine is commonly seen in patients with diabetes mellitus and the harmless condition called renal glycosuria. Blood glucose test is necessary to confirm diabetes mellitus.


Protein in the urine usually indicates the presence of kidney disorder and should be present in every urine sample. Small amount of protein may be present in concentrated urine of normal person and also after strenuous exercise.


Ketones are present in urine of persons after acute starvation or patients with severediabetes mellitus.


Blood in the urine usually comes from the kidney and urinary tract. When associated with pain, stones is the likely cause. Painless blood in the urine could be due to cancerous growths. In female, blood from menstruation can sometimes contaminate the urine sample.



This is equivalent to blood in the urine. Counts of less than 10 per HPF is usually of little significance.


Counts of less than 10 per HPF can be found in normal urine. Infections in the kidney and urinary tract are associated with markedly increased counts. A culture test will be required to detect the nature of the infection.


They are cells lining the urinary tract. Occasionally cancers of the kidney or urinary tract is associated with abnormal epithelial cells in the urine. High counts in female urine suggest contamination from vaginal discharge.


Casts are formed in the kidney tubules from protein filtered from the blood. They are present in the larger numbers in kidney disorders associated with protein the urine. A few casts may be seen in urine of normal people especially after exercise.


The urine contains many substances in solution and depending on the reaction of the urine, they can become insoluble and form crystals. If crystals are present in large amounts and for prolonged periods, stone formation may occur.



Persons infected by the HIV viruses will produce the antibody after 3 to 4 weeks time. However, this antibody cannot affect the virus and therefore cannot protect the patient. It only serves as a marker of infection. HIV antibody positive persons can remain well for years before the onset of symptoms and signs of the disease AIDS.

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