HOW TO READ YOUR HEALTH SCREENING REPORT (BLOOD, URINE AND FAECAL ANALYSIS)

How often have you gone "actually what do all these mean?" when you received your health checkup results? Different hospitals and clinics have different layouts, but they should include similar information. Here are some of the terms commonly found in health screening reports, and this is what they mean.

After understanding the medical history and physical examination portion of your health screening report (included in the previous blog post, click here), it is now time to delve into the lab values portion, which provides more insights into your health status. The information below is not exhaustive. If you have any questions, feel free to leave them in the comments below or approach your healthcare professional!

The physical examination section is followed by lab results, which are done using blood, urine, and fecal tests. The tables below show what each parameter means and the corresponding target levels of each.

The glucose levels indicated in the table below refers to fasting glucose (Do remember that you are not supposed to eat anything 8 hours before your health checkup!) Also, do note that values can differ between healthcare institutions due to the different testing kits used.

	What is it?	Low	Normal/desirable	High
Total cholesterol levels	The overall amount of cholesterol found in the blood	-	<200 mg/dL	200-239 mg/dL (borderline) >240 (high)
HDL	High-density lipoprotein. Also known as the "good" cholesterol. Low levels can decrease the risk of heart diseases	<40 mg/dL	-	-
LDL	Low-density lipoprotein. Also known as the "unhealthy" cholesterol. It has potential to clog arteries, resulting in a stroke	-	<100 mg/dL	130-159 mg/dL (borderline) 160-189 mg/dL (high) >190 mg/dL (very high)
Total cholesterol/HDL ratio	Obtained using total cholesterol/HDL and assesses the risk of heart diseases	-	1.5-4.5	-
Triglyceride	The main constituent of body fat. Very high levels can result in increased risks of heart diseases and stroke.	-	<150 mg/dL	150-199 mg/dL (borderline) 200-499 mg/dL (high) >500 mg/dL (very high)
Glucose	The main type of sugar taken into the body. Low levels correspond to hypoglycemia, where patients may start feeling faint. High levels can result in hyperglycemia, and long term hyperglycemia can lead to diabetes and other related complications.	<3.9 mmol/L	3.9-7.0 mmol/L	>7.0 mmol/L
Uric acid	Natural waste products from the breakdown of purines (type of compound found in food). High levels may indicate gout.	-	3.4-7.6 mg/dL	>7.6 mg/dL
Potassium	An electrolyte that regulates fluid balance, muscle contractions, and nerve signals. Deviations from the normal value can result in feelings of muscle weakness and cramps. It can be due to medicine intake or kidney problems.	<3.3 mmol/L	3.3-5.1 mmol/L	>5.1 mmol/L
Sodium	Maintains the balance of water in and around cells. Deviation from the normal value can result in muscle weakness, headache or muscle twitching, depending on the level iteself.	<135 mmol/L	135-150 mmol/L	>150 mmol/L
Urea	Produced by the body during the breakdown of amino acids. Increased levels may be due to dehydration and renal impairment, congestive heart failure, and unusually high intake of proteins. Decreased levels can be due to kidney failure and malnourishment.	<10 mg/dL	10-50 mg/dL	>50 mg/dL
Creatinine	Produced by muscles during the breakdown of creatinine. High levels may mean kidney problems or maybe simply due to increased meat intake or low blood volume. Its production is dependent on muscle mass.	<0.50 mg/dL	0.5-1.6 mg/dL	1.6 mg/dL
Calcium	A mineral involved in the building and maintenance of bones, helping blood to clot and muscles to contract.	<8.4 mg/dL	8.4-10.2 mg/dL	>10.2 mg/dL
Phosphate	Build and repair bones and teeth, and help nerves and muscles function. Overly low levels can cause bones to break down. Dangerously low levels can result in difficulty breathing.	<2.7 mg/dL	2.7-4.5 mg/dL	>4.5 mg/dL

In Singapore, glucose levels are usually measured in mmol/L, but many other countries use mg/dL as well. While the values help provide a clue to the current state of the body, it is important to note that such values differ according to individuals. Diagnosis of diseases is up to the discretion of the doctor and the trends presented by the patient over a few health screenings.

Liver function tests are done on the blood to check for any abnormalities within the liver.

	What is it?	Normal levels	Remarks
Bilirubin, total	A yellowish substance that is formed during the breakdown of hemoglobin.	1.5 mg/dL	High levels can be due to underlying problems involving the liver, red blood cells, or gallbladder.
Protein, total	The total amount of albumin and globulin in the blood.	6.4-8.5 g/dL	High levels can be due to dehydration. If it is too low, it may be due to liver or kidney problems, or inabilities to absorb proteins.
Albumin	A type of protein made in the liver and serves to keep fluid within the bloodstream while carrying various substances around the body.	3.4-5.1 g/dL	Low levels may indicate liver or inflammatory diseases. High levels may be due to infections, burns, or heart attack.
Globulin	Protein involved in blood clotting and fighting infection made in the liver by the immune system.	1.9-3.6 g/dL	High levels may be due to blood or autoimmune diseases.
Albumin/globulin ratio	Abnormal levels are indicative of disease in the liver, kidney or intestines.	Slightly higher than 1 (For Raffles hospital the value is 1.2-2.5)	Overly low levels are suggestive of an autoimmune disease.
ALP	Alkaline phosphatase (enzymes found in bones or the liver) levels, that can help diagnose liver damage or bone disorders.	39-117 U/L	High levels may indicate liver or bone-related problems.
AST/SGOT (Aspartate aminotransferase/ serum glutamic oxaloacetic transaminase)	It is an enzyme made by the liver	<38 U/L	Elevated levels are a sign of liver damage, but it can also mean problems with the heart or kidneys.
ALT/SGPT (Alanine aminotransferase/ Serum glutamic pyruvic transaminase)	Checks for the levels of alanine aminotransferase which is normally found in the liver and heart cells. When the liver or heart is damages, these enzymes get released into the blood.	<41 U/L	Elevated levels are a sign of liver or heart damage, thus this number has to be looked at together with the other values found in this section to make a better diagnosis. Values close to 41 may also be a sign of fatty liver.
CGT (Gamma-glutamyl transferase)	The enzyme is found in many different organs within the body. The test is used to determine the presence of liver or bile duct disease.	11-49 U/L	Levels should be looked at together with ALP levels. Levels are usually higher when the liver is damaged. It can also be increased when there is an intake of alcohol.

ALP and GGT levels are usually used together as both levels will be elevated in liver disease, but only ALP will be elevated in diseases affecting the bone tissue. Also, do note that the exact number may vary between individuals, so do check with your health professionals if you have any doubts.

Levels of different components of the blood will also be included as they can provide an insight into any possible conditions the person may have.

	What is it?	Normal levels	Remarks
White blood cell	Cells of the immune system that helps protect against diseases.	4.0 x 10^9 - 11.0 x 10^9 /L	High levels may mean a potential infection or blood-related cancers.
Polymorphs	Immune cells containing granules with enzymes that are released during infections, allergic reactions, and asthma.	40-75%	High levels may be due to an infection or inflammatory condition while low levels may be due to stress or malnutrition.
Lymphocytes	A subset of white blood cells including natural killer cells, T cells and B cells.	20-45%	High levels may be due to an infection or inflammatory condition while low levels may be because of stress or malnutrition.
Monocytes	Type of white blood cells that differentiate into macrophages which helps the body recognize antigens.	2-10%	High levels may be due to chronic infections, autoimmune or blood disorders, or other medical conditions.
Eosinophils	A type of white blood cell usually responsible for combating parasites and certain infections	0-6%	An elevated level is usually indicative of a parasite infection.
Basophils	​Type of white blood cell that contains heparin (prevent blood clotting). During allergic reactions, it is also responsible for releasing histamine and causing the body to produce immunoglobulin E	0-1%	An elevated level is usually due to a possible chronic inflammation or conditions resulting in the overproduction of basophils.
Red blood cells	​Responsible for transporting oxygen and glucose, as well as carbon dioxide. The red color is due to hemoglobin that is contained in the cells.	4.5 x 10^12 - 6.5 x 10^12 /L	Low levels are usually due to anemia, where there are insufficient red blood cells available to transport sufficient oxygen for use.
Hemoglobin (Hb)	A compound found within red blood cells that carries oxygen and attaches to glucose	Male: 13.5-17.5 g/dL Female: 12.0-15.5 g/dL	Low levels are usually due to anemia, which can be due to many different causes.
Hematocrit	The volume percentage of red blood cells in the blood.	Male: 40.7%-50.3% Female: 36.1%-44.3%	High levels can indicate dehydration and low levels are due to anemia.
Mean cell volume	Refers to the average volume of a red blood cell, helping with the diagnosis of anemia and its type.	76-96 fL	In anemia, levels below normal point to microcytic anemia, values within the normal range are normocytic anemia, and values above normal range point to macrocytic anemia.
Mean cell Hb	The average quantity of hemoglobin found in a single red blood cell.	27-32 pg	Low values usually point to iron deficiency anemia while high values indicate macrocytic anemia.
RDW (red cell distribution)	Range in volume and size of red blood cells.	11.5-14.5%	High levels can be due to nutrient deficiency, showing a big range, while low levels simply mean that the red blood cells are of similar sizes.
Mean cell Hb concentration	The concentration of hemoglobin in a given volume of packed red blood cells.	31-36 g/dL	A low value is usually indicating of iron-deficiency anemia where there there is very little hemoglobin in the red blood cells.
Platelets	Helps to stop bleeding by clotting to plug the wound and stopping blood from escaping further.	140 x 10^9 - 150 x 10^9/L	Low levels can result in problems with clotting while very high levels can result in clotting within the blood vessels or spontaneous bleeding within the gastrointestinal tract.
Peripheral blood film	It is the observation of the blood cells using a microscope that is important in characterization of a myriad of diseases	The majority of RBCs are normochromic and normocytic. No early cells are seen.	-

Sometimes, high levels of any component may be indicative of cancers as well. Check with your healthcare provider if you are unsure what your laboratory results mean.

Tumor markers are then checked to test for cancer likelihood and the presence of tumors.

	What is it?	Normal levels	Remarks
Carcinoembryonic Ag	It is a type of antigen (glycoprotein) that is important in cell adhesion, which is highly involved in tumor formation.	2-4 ng/mL, up to 5.0 ng/mL	High levels may be indicative of the early stages of colon cancer.
PSA (Prostate-specific antigen)	A protein produced by cells of the prostate gland.	0.00-4.00 ug/L	This test is mostly done in males as they are more highly predisposed to getting prostate cancer.

Thyroid function tests are used to measure thyroid hormone levels within the body, which affect the growth and metabolism of the person. Both values shown in the table below have to be looked at together in order to determine the problem the person is suffering from (if any).

	What is it?	Normal levels	Remarks
TSH	Thyroid-stimulating hormone, which stimulates the thyroid gland to produce hormones.	0.270-4.200 uIU/mL	High levels may indicate hyperthyroidism, where there is too much stimulation of the production of thyroid hormones, while low levels indicate hypothyroidism.
Free T4	The hormone produced by the thyroid gland that plays a role in growth and metabolism.	0.93-1.71 ng/dL	High levels may indicate hyperthyroidism, where levels of thyroid hormones (T4) are too high, while low levels indicate hypothyroidism.

** Some common symptoms of hyperthyroidism include abnormal weight loss, rapid heartbeat, anxiety, and sweating.

** Common symptoms of hypothyroidism: usually no symptoms at the early stage but includes increased sensitivity to cold, fatigue, thinning hair, slow heart rate, puffy face, and dry skin.

Immunology tests are mainly used to test for the presence of antibodies for hepatitis to determine if there should be recommendations for vaccination. Clinics usually screen for hepatitis as it is a very common reason behind liver failure.

Urine analysis looks at the makeup of your urine that is collected on the day of your health check-up. It mainly helps with looking out for problems in the kidney, or any abnormalities in the excretion function of the body.

	​What is it?	Normal values	Remarks
pH	The potential of hydrogen, which measures the hydrogen ion concentration in the urine.	5.0-7.0	pH <5.0 hints at acidosis where there is too much acid within the body, while pH>7.0 can mean alkalosis where internal body conditions are not acidic enough. This is very important because the body's pH has to be controlled very tightly to maintain the structure of proteins and enzymes that carry out bodily functions.
S.G (specific gravity)	The density of urine relative to that of water.	1.005-1.030	If the specific gravity of urine is too high, it can mean dehydration or potential kidney problems where water is not eliminated properly. Low specific gravity can hint at kidney diseases or indicate diabetes insipidus (which is a condition where the person urinates too much dilute urine).
Protein	Molecules in the body that perform many different functions made from amino acids.	Negative/trace	A positive result of more than a trace amount may be suggestive of a kidney problem that causes too many proteins to leak out from the bloodstream.
Leucocytes	Also known as white blood cells, which are cells of the immune system that helps protect against diseases.	Negative	A positive result may be due to inflammation in the urinary tract or kidneys.
Glucose	The main type of sugar taken into and stored in the body.	Negative	A positive result may reveal kidney problems or diabetes. This is usually looked at together with the blood test results. The doctor might even ask you back for a follow-up.
Ketones	Made by the liver when there is insufficient insulin to turn glucose into energy within the body. It is resultant of the breakdown of fats into energy within the body.	Negative	A positive result may reveal the presence of diabetes mellitus (high blood sugar) as the body is utilizing fats as energy, producing ketones as waste products which are removed via the urine.
Nitrite	​​​Converted from nitrates by some bacteria.	Negative	A positive result may mean a presence of bacterial infection in the urinary tract.
Blood	The substance in the body that transport nutrients and waste materials via the circulatory system.	Negative	​A positive result may be indicative of a kidney problem as blood is able to leak into the urine from the blood vessels.
Bilirubin	A yellowish substance formed during the breakdown of hemoglobin.	​Negative	Positive results may mean liver disease or damage, as it could be released by damaged liver cells into the bloodstream and enter the urine via the kidneys.
​Urobilinogen	Colorless by-product of bilirubin reduction.	Negative	​Positive or high levels can mean liver disease, and this value should be looked at closely with the presence of bilirubin.
Red blood cells	Responsible for transporting oxygen and glucose, as well as carbon dioxide. The red color is due to hemoglobin that is contained in the cells.	0-3 cell/uL	High levels can mean infection, traumas, tumors, or kidney stones.
White blood cells	Cells of the immune system that helps protect against diseases.	0-6 cells/uL	High levels are usually indicative of infections in the urinary tract.
Epithelial cells	Cells lining the surface of the urinary tract. Small amounts are usually present.	0-15 cells/uL	High numbers can mean a yeast or urinary tract infection, kidney or liver disease, or cancer.
CASTS	Tiny tube-shaped particles that are found when urine is examined under the microscope. It may contain white blood cells, red blood cells, kidney cells, protein and fats.	Negative	Presence can indicate kidney disease. If the cells are not in CASTS form, the infections will more likely be due to problems in the urinary tract.
Crystals	​Tiny particles made up of many different possible compounds such as uric acid.	Negative	The presence may be indicative of kidney failure, although sometimes healthy individuals may produce.
Others	Refers to any other abnormalities found in the urine that does not belong under of the above categories.	Negative	-

In the fecal analysis portion, immunological fecal occult blood is looked at to check for colon cancer. Cancer within the digestive tract usually results in bleeding, and this test can help to identify such problems.

Most health screening tests will also include a chest x-ray, which ensures the size of the heart is normal and no lung lesion is seen. This is to rule out any problems that may have no symptoms but affect the functions of the heart and lungs.

Hope the above information and stay tuned to our next health-related blog, which will be about Diabetes Mellitus!