The Critical Blood Tests
The following is a list of the major types of blood tests that your doctor may perform to help determine your current state of health (diagnosis) and your future state of health (prognosis). These tests are very important in your overall health planning.
Fasting Blood Glucose measures the amount of glucose (sugar) in the blood.
Hemoglobin A1C measures the percentage of glucose in the blood during the past 2 to 3 months.
Glucose, formed by the digestion of carbohydrates and the conversion of glycogen by the liver is the primary source of energy for most cells. It is regulated by insulin, glucagon, thyroid hormone, liver enzymes and adrenal hormones.
Glucose is elevated by diabetes, liver disease, obesity, pancreatitis, steroids, stress, or diet. Low levels may be indicative of liver disease, overproduction of insulin, hypothyroidism, or alcoholism.
Range for Fasting Blood Glucose: 80 to 120 mg/dl;
Optimum value: < 100 mg/dl
Range for Hemoglobin A1C: 4.2% to 5.5%; Optimum value: < 5.0%
Blood Pressure measures the pressure (force per unit area) exerted by the blood on the walls of the blood vessels.
The first number is the systolic pressure, which measures the force at which the heart contracts. The second number is the diastolic pressure, which measures the pressure when the heart is at rest (between beats).
High blood pressure is an indication that one or more of the body’s systems is not functioning properly, causing the heart muscle to work harder to push the blood throughout the body.
Systolic (first number): < 120 mm Hg
Diastolic (second number): < 80 mm Hg
In addition, measuring the blood pressure in other parts of the body such as the ankle, leg or toe can help to diagnose other problems that may go undetected. For example, according to recent research from Sweden, measuring toe blood pressure can be an effective screening method to identify diabetics with lower extremity arterial disease. Unlike the routine arm blood pressures where diastolic and systolic pressure are measured, extremity blood pressures measure only systolic pressure.
Blood Cholesterol measures the amount of lipids (fat) in the blood.
Cholesterol is a critical fat that is a structural component of cell membrane and plasma lipoproteins, and is important in the synthesis of steroid hormones, glucocorticoids, and bile acids. Mostly synthesized in the liver, some is absorbed through the diet, especially one high in saturated fats. High density lipoproteins (HDL), which indicates more (dense) protein and less cholesterol, is desired as opposed to the low density lipoproteins (LDL), which indicates less protein and room for more cholesterol within the molecule.
Elevated cholesterol levels have been seen in atherosclerosis, diabetes, hypothyroidism and pregnancy. Low levels are seen in depression, malnutrition, liver insufficiency, malignancies, anemia and infection.
Triglycerides, stored in adipose tissues as glycerol and fatty acids, are reconverted as triglycerides by the liver. Ninety percent of the dietary intake and ninety-five percent of the fat stored in tissues are triglycerides.
Increased levels may be present in atherosclerosis, diabetes, hypothyroidism, liver disease, pancreatitis, myocardial infarction, metabolic disorders, and toxemia. Decreased levels may be present in chronic obstructive pulmonary disease, brain infarction, hyperthyroidism, malnutrition, and malabsorption.
LDL or Low density lipoprotein is the cholesterol remnants of the lipid transport vehicle VLDL (very-low density lipoproteins).
A high level of LDL is an indication of a clogged liver, an unbalanced metabolic system, or possible arterial wall damage (atherosclerosis). Due to the expense of direct measurement of LDL, the Friedewald formula is used:
LDL = Total Cholesterol - HDL Cholesterol - Triglycerides/5.
When triglyceride levels are greater than 400, this method is not accurate.
HDL or High density lipoprotein is the cholesterol carried by the alpha lipoproteins.
A high level of HDL is an indication of a healthy metabolic system if there is no sign of liver disease or intoxication. HDL inhibits cellular uptake of LDL and serves as a carrier that removes cholesterol from the peripheral tissues and transports it back to the liver for catabolism and excretion.
The normal ranges for these cholesterol parameters are:
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Total Cholesterol (TC): < 200 mg/dl
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Low Density Lipoprotein (LDL): < 130 mg/dl
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High Density Lipoprotein (HDL): > 40 mg/dl
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Triglycerides: < 150 mg/dl
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TC/HDL Ratio: < 4:1; LDL/HDL Ratio: < 3:1
Note: Actually the ratios are better indicators of your cholesterol health than the absolute numbers, which can be misleading, especially if you have a high HDL, which is a good indicator.
Body Mass Index (BMI) provides a measure of weight relative to height to use as a guideline to determine whether your weight is at a normal, overweight, or obese level.
BMI Range: 20 to 25
BMI greater than 25 indicates an overweight level.
BMI greater than 30 indicates an obese level.
Waist Size: Actually the size of one’s waist may be a better measure and indicator of one’s health state. In general, if the waist size exceeds 40 inches (for a male), or 35 inches (for a female), this indicates a risk factor for developing diabetes and other weight-related health problems. Keep in mind that these are only guidelines for average-sized people.
Note: Refer to the
Obesity web page
for more information about obesity and excessive weight gain.
Cardiac Risk/Inflammation Factors include homocysteine, lipoprotein (a), C-reactive protein (CRP), and fibrin; and, are better indicators of cardiovascular disease and inflammation than your level of cholesterol.
They measure the amount of inflammation and amino acids in the blood. However, since your doctor may not order these tests until he/she has determined that you may be at risk for cardiovascular disease, you may need to request these tests, especially if you are not making any significant progress with your health.
- Homocysteine is a sulfur-containing amino acid created by a normal metabolic breakdown of the amino acid methionine; and is an indicator of inflammation.
- Lipoprotein (a) is produced by the liver to repair arterial injuries due to a lack of Vitamin C to produce collagen for tissue repair.
- C-Reactive Protein (CRP) is a plasma protein produced by the liver in response to inflammation.
- Fibrin is an insoluble protein that is deposited around a wound in the form of a mesh to dry and harden, so that bleeding stops. Platelets, a type of cell found in blood, release the enzyme thrombin when they come into contact with damaged tissue, triggering the formation of the soluble protein, fibrinogen. Fibrinogen is then converted to fibrin as the final stage in blood clotting, which helps to repair damaged arterial walls.
The normal ranges for these cardiac risk/inflammation parameters are:
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Homocysteine: < 17 umol/L
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C-Reactive Protein (CRP): < 10 mg/L
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Lp (a): < 25 mg/dl
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Fibrin: 145-348 mg/dl
These numbers are only guidelines and may be slightly different depending on the test methods used by your doctor’s lab. Therefore, when you review your blood and urine test results with your doctor, you should always ensure that you understand the normal range for each blood or urine test and how far you are outside that range.
Waste Products include blood urea nitrogen (BUN), creatinine, and uric acid.
They indicate the health of the kidneys. Blood Urea Nitrogen (BUN) is the end product of protein metabolism and its concentration is influenced by the rate of excretion. Creatinine is the waste product of muscle metabolism. Its level is a reflection of the bodies muscle mass. Uric acid is the end product of purine metabolism and is normally excreted through the urine. Bun/Creatinine Ratio is a good measurement of kidney and liver function.
Electrolytes/Minerals indicate the health of the kidneys, adrenal glands, parathyroid glands, and the acid/alkaline status of the blood.
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Potassium helps to regulate blood pressure and heart function; along with sodium, helps to maintain osmotic balance; is involved in acid-base balance; and, is needed for proper nerve and muscle action. It has an inverse relationship with sodium -- when potassium is increased, sodium decreases and vice versa.
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Sodium functions in the body to maintain osmotic pressure, acid-base balance and to transmit nerve impulses. It functions with chloride and bicarbonate to maintain a balance of positive and negative ions (electrically charged particles) in our body fluids and tissues.
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Calcium levels are highly sensitive to elements such as magnesium, iron and phosphorus as well as hormonal activity, Vitamin D levels, alkalinity and acidity, and many different drugs.
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Carbon dioxide level is related to the respiratory exchange of carbon dioxide in the lungs and is part of the bodies buffering system.
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Magnesium plays a major role in the metabolism of glucose. It is required for the formation of enzymes that release energy from food; and, is used in the production of cellular energy and to create protein.
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Phosphorous is needed for its buffering action, calcium transport and osmotic pressure.
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Chloride influences osmotic pressure, as it helps to keep the amount of fluid inside and outside of cells in balance.
Proteins measure the amount and type of protein in the blood.
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Albumin is the major constituent of serum protein (usually over 50%). It is manufactured by the liver from the amino acids taken through the diet. It helps in osmotic pressure regulation, nutrient transport and waste removal.
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Globulin is important for its immunologic responses, especially its gamma portion.
Liver Enzymes measure specific liver enzyme levels to assess how well the liver and the body’s systems are functioning and whether there has been any tissue damage; indicating injury to the cells of the muscles, liver, or heart.
Enzyme tests include Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Alkaline phosphatase (ALP), Gamma-Glutamyl Transpeptidase (GGT), Lactic acid dehydrogenase (LDH), and Bilirubin.
Thyroid tests measure the levels of the thyroid hormones in the blood, Thyroxine (T4) and Triiodothyronine (T3).
Complete Blood Count (CBC) measures the quantity of different cells in the blood.
Other blood count tests include White Blood Count (WBC), Red Blood Count (RBC), Platelet Count (PLT), Mean Corpuscular Volume (MCV), and Hemoglobin (Hgb or Hb).
Bone Density measures the density of the bones to identify potential bone loss -- osteopenia (the early stage of bone loss) or osteoporosis.
Blood pH measures the alkalinity/acidity of the blood, and may indicate acidosis if the pH level is less than 7.365.
Urine Tests can be performed to provide additional insight, especially concerning the health of the kidneys.
Microalbumin measures the amount of protein that is not removed by the kidneys and has leaked into the urine. When kidneys function properly, they filter out waste products from the blood, but when the kidneys become damaged, the waste products remain in the blood and protein leaks into the urine.
At first, when the damage is just beginning, only very small amounts of albumin escape into the urine, a condition known as microalbuminuria. In later stages of kidney disease, large amounts of protein leak into the urine (> 30g/dl), causing a condition called macroalbuminuria, also known as proteinuria.
Ketones measure the level of ketones, which are the by-product of the fat burning process that occurs in the absence of insulin. Other urine tests include pH (acidity for your urine), specific gravity (SG), glucose, protein, bilirubin, nitrate, leukocyte esterase, and sediment
Excretory Factors are usually overlooked, but they can tell your doctor a lot about what you’ve been eating and how your body has been processing what you eat on a daily basis. Infrequent bowel movements (constipation) or indigestion is usually the first sign of problems in the gastrointestinal tract.
Bowel movement frequency, texture, shape: 3-4 times per day (1 per meal), soft, peanut butter-like texture, slightly S-shaped
Urination frequency, color: 4-6 times per day, yellow-straw in color
Note: This is not a comprehensive list of tests. Get the
Blood Tests PDF for the comprehensive list. Depending on your health, there are many other blood tests and medical diagnostic tests that your doctor may perform to better understand your health state.
Other tests include hormone tests, vitamins/minerals tests, liver detoxification tests, amino acids tests, fatty acid analysis, intestinal permeability test, stool test, immune system tests, oxidative stress analysis, and hair analysis tests.
Although health insurance coverage may be a concern, do not hesitate to ask your doctor if there is an additional test that he/she could perform that would better define your health state.
If you and your doctor do not fully understand your health state, it may be difficult to devise an effective “get well” plan. As a result, two to three years later, you may find that you’re either not feeling better or you’re taking more medication. Both of these are signs that indicate that the original diagnosis may have been incorrect.
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