Understanding Routine Laboratory Tests Results

Dr. Nazmul Hasan BHMS, M.Phil(Course)

Medical laboratory tests involve analyzing samples of blood, urine and/or other body fluids or tissues in order to better understand a person’s health state. Some lab tests provide precise information about specific health issues, whereas others provide more general information. A doctor combines information from medical lab tests with a physical exam, health history and other diagnostic tests (such as x-rays or ultrasound) before he/she comes up with a diagnosis for patients.

Understanding Blood Tests

What a CBC is? The most common blood test analyzed in a medical lab is a complete blood count (CBC). A CBC measures all the different types of cells and elements in blood, such as red blood cells (RBC), white blood cells (WBC), platelets and hemoglobin. RBCs contain hemoglobin, whereas WBCs are part of immune system and help to destroy microorganisms such as viruses, bacteria and fungi.


  • A low RBC count suggests anemia (not enough oxygen getting to tissues), although too many RBCs (called erythrocytosis) may indicate bone marrow disease.
  • A low WBC count (called leukopenia) may also suggest a bone marrow problem or a potential side effect from taking medications — common problem while undergoing chemotherapy for cancer. On the other hand, a high WBC count (called leukocytosis) usually indicates that body is  fighting an infection.
  • Normal RBC ranges are different between the genders. Men have 20-25% more RBCs because they tend to be larger and have more muscle tissue, which requires more oxygen.
  • Low Platelet count indicates risk of capillary bleeding increased.

What is cholesterol panel? Other components can be added to routine, such as a cholesterol panel (also called a lipid panel). Cholesterol panel is helpful for determining risk of cardiovascular disease, such as atherosclerosis, heart attack and stroke. A cholesterol / lipid profile includes measurements of total blood cholesterol (includes all the lipoproteins in your blood), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol (LDL) and triglycerides, which are fats that are usually stored in fat cells.

  • Ideally, total cholesterol should be less than 200 mg/dL and patient should have a favorable ratio of HDL (the “good” kind) to LDL (the “bad” kind) that approaches 1:2 in order to reduce risk of cardiovascular disease.
  • HDL removes excess cholesterol from the blood and transports it to liver for recycling. Healthy levels are greater than 50 mg/dL (ideally above 60 mg/dL).
  • LDL shuttles cholesterol from your liver to cells that need it, as well as to blood vessels in response to injury and inflammation — this can trigger clogged arteries (called atherosclerosis). Healthy levels are lower than 130 mg/dL (ideally less than 100 mg/dL).
  • With this results a physician may get an indication of selection of medicine, such as increased LDL in contraindicated with Medicago Sativa (Alfalfa).

What is blood glucose tests. Another potential component, that may include in routine is a blood sugar (glucose) test. Blood sugar tests measure the amount of glucose circulating in bloodstream, usually after fasting for at least 8 hours. Glucose tests are usually ordered if doctor suspects that, patients may have a type of diabetes (types 1 or 2, or gestational). Diabetes develops when pancreas doesn’t produce enough insulin hormone (which functions to grab glucose from the blood and deliver it to cells) or the cells of the body “ignore” the effects of insulin. Thus, diabetics have chronically high blood glucose levels (called hyperglycemia), which is greater than 125 mg/dL.

  • People at high risk for diabetes have blood sugar levels between 100 – 125 mg/dL – if anyone in this range, he /she might be referred to as “pre-diabetic.”
  • Need to Keep in mind there are other causes of high blood sugar, such as acute and chronic stress, kidney disease, hyperthyroidism and a cancerous or inflamed pancreas gland.
  • Very low levels of glucose (less than 70 mg/dL) is called hypoglycemia and can be caused by taking too much insulin medication, alcoholism, lack of proper glucose intake and failure of various organs (liver, kidneys and/or heart).
Appreciate what the CMP is. A comprehensive metabolic panel (CMP) measures other components in the blood, such as electrolytes (charged mineral salts needed for nerve conductance and muscle contraction), organic minerals, protein, creatinine, liver enzymes and glucose. A CMP is typically ordered to determine patient’s overall health, and also to check the function of his kidneys, liver and pancreas, as well as electrolyte levels and acid/base balance. CMPs are often ordered along with CBCs as a part of standard routine medical exams and annual physicals.
  • Sodium is needed for regulating fluid levels and allowing nerves and muscles to function, but too much in the blood causes hypertension (high blood pressure) and increases your risk of cardiovascular disease. Normal sodium levels are between 136 – 144 mEq/L. Increased Na will be diagnosed as Hypernatremia and decreased Na will be diagnosed as Hyponatremia. When sodium levels go up, potassium levels go down (Hypokalemia), and when sodium levels go down, potassium levels go up (Hyperkalemia). Potassium levels are also affected by a hormone called aldosterone, which is made by the adrenal glands. CO2 indicates the level of gas in the blood, which helps to understand intensity to dyspnoea. Chlorine itself may not have any direct but a very essential element to help the others to work in properly.
  • Liver enzymes (ALT and AST) become elevated when liver is injured or inflamed — caused by physical trauma, infection, alcoholism or drug use (prescription, over-the-counter and illicit).
  • If your blood urea nitrogen (BUN) and creatinine levels are elevated, that likely means your kidneys have problems. BUN should be between 7 – 29 mg/dL, whereas your creatinine levels should be between 0.8 – 1.6 mg/dL.

Understanding Urine Lab Test

 What is urine analysis (urinalysis)? A urinalysis detects the byproducts of normal / abnormal metabolism, cells, protein and bacteria in urine. Healthy urine is typically clear hay-water looking, without a bad odor and sterile, which means without significant numbers of bacteria. Many metabolic and kidney disorders can be caught in their early stages by screening for abnormalities via urinalysis. These abnormalities can include higher-than-normal concentrations of glucose, protein, bilirubin, RBCs, WBCs, uric acid crystals and bacteria.

  • Physician may recommend urinalysis if she/he suspects a metabolic condition (diabetes, thyroid and pituitary gland disorders), kidney disease or a urinary tract infection (UTI).
  • For urinalysis, need to collect 1-2 ounces / 28-60 ml of mid-stream urine (not the initial portion out of urethra) into a sterile plastic cup. Collecting the sample first thing in the morning is usually recommended. Urine sample is analyzed three ways in the lab: via visual exam, dipstick test and microscopic exam.
  • Ideal urine will be slight-light hay watercolor, without any sedimentation, and with proper specific gravity. There will be no RBC. WBC may upto 2-4/HPF and Epithelial cell may upto 3-5/HPF.
  • The main evidence of a UTI from the dipstick portion of urinalysis is the presence of nitrites or leukocyte esterase (a product of WBCs)
  • Normally, there isn’t significant amounts of protein (albumin) in urine. However, when urine protein levels are high (called proteinuria), it can be an early sign of kidney disease. Proteinuria is also common with multiple myeloma and various types of cancer.
  • Kidney disease can also cause blood (RBCs) to be in urine, as well as high acidity and specific gravity (the concentration of the urine). Crystals in urine may be a sign of kidney stones or gout.
  • The presence of sugar (glucose) and ketones in urine is usually indicative of diabetes. Thus, diabetics have too much glucose in both their blood and urine.
  • Other conditions and diseases can be identified from urinalysis also, such as liver disease or inflammation, kidney and bladder cancer, chronic inflammation somewhere in the body and pregnancy. These parameters aren’t always looked at routinely in the medical blood lab.
  •  Bilirubin is a byproduct of RBC breakdown and normally not found in urine. Any bilirubin in your urine can indicate liver damage or disease, such as cirrhosis or hepatitis. It may also indicate gallbladder disease.The presence of abnormal looking cells, as well as WBCs and RBCs in the urine, can be indicative of cancer somewhere in the genitourinary system. If cancer is suspected, blood tests and cell cultures are usually performed too.
  • Pregnancy could be detected with urine analysis by detecting human chorionic gonadotropin (hCG) in urine sample, which is a hormone made by the placenta of pregnant women. The hormone can also be detected in the blood, although pregnancy test kits sold at pharmacies measure hCG in urine.