Blood & Urine Exam
Last updated date: 06-Mar-2023
Originally Written in English
Blood & Urine Exam
A blood test is a laboratory study of a blood sample taken from a vein in the arm using a hypodermic needle or through fingerprick. Multiple blood component tests, such as a glucose test or a cholesterol test, are sometimes bundled together into a single test panel known as a blood panel or blood work.
Blood tests are frequently used in medical settings to detect physiological and biochemical conditions such as illness, mineral content, pharmaceutical medication efficacy, and organ function. A basic metabolic panel or a full blood count are two examples of clinical blood panels. Blood tests are frequently used to identify drug usage in drug testing.
Clinical urine tests examine the physical and chemical characteristics of urine as well as its microscopic appearance in order to help in medical diagnosis. Urinalysis is a word that relates to the gross (macroscopic) inspection of urine, the chemical assessment using urine test strips, and the microscopic analysis of urine.
The naked eye (or other senses) can be used to measure parameters such as volume, color, transparency, odor, and specific gravity; urine test strips measure chemical properties such as pH, glucose concentration, and protein levels; and light microscopy is used to identify elements such as cells, urinary casts, crystals, and organisms. Urine electrolyte levels, drug testing, pregnancy testing, and microbiological culture are all regularly conducted on urine samples.
Many diseases and medical problems cannot be diagnosed just by blood and urine testing. Other criteria may be considered by your doctor to confirm a diagnosis. Your signs and symptoms, medical history, vital signs (blood pressure, respiration, pulse, and temperature), and findings from various tests and treatments are all examples of these elements.
Indications for Blood Tests
Blood tests aid doctors in the detection of various illnesses and ailments. They also aid in determining how effectively your organs operate and how well therapies are functioning.
Blood testing, in particular, can assist clinicians in the following ways:
- Examine the performance of organs such as the kidneys, liver, thyroid, and heart.
- Cancer, HIV/AIDS, diabetes, anemia, and coronary heart disease are just a few of the illnesses and ailments that can be diagnosed.
- Determine whether you are at risk for heart disease.
- Check to see if the medications you're taking are effective.
- Examine how well your blood clots.
Types of Blood Tests
Some of the most common blood tests are:
1. A complete blood count (CBC):
The CBC can aid in the detection of blood illnesses and disorders such as anemia, infections, clotting issues, blood malignancies, and immune system abnormalities. As mentioned in the next paragraphs, this test evaluates several different components of your blood.
- RED BLOOD CELLS:
Red blood cells are responsible for transporting oxygen from your lungs to the rest of your body. Anemia, dehydration (too little fluid in the body), bleeding, or another condition can all cause abnormal red blood cell counts.
- WHITE BLOOD CELLS:
White blood cells are part of your immune system, which is responsible for fighting infections and disorders. Abnormal white blood cell counts might indicate an infection, blood malignancy, or an immune system problem.
A complete blood count (CBC) determines the total amount of white blood cells in your blood. A differential CBC examines the quantities of various types of white blood cells in your blood.
Platelets are blood cell fragments that aid in the clotting of your blood. They join together to halt bleeding by sealing wounds or breaches in blood vessel walls.
Abnormal platelet counts may indicate a bleeding condition (insufficient clotting) or a thrombotic disorder (too much clotting).
Hemoglobin is an iron-containing protein found in red blood cells that transports oxygen. Anemia, sickle cell anemia, thalassemia, and other blood diseases can all be caused by abnormal hemoglobin levels.
Excess glucose in your blood can bond to hemoglobin and boost your hemoglobin A1c level if you have diabetes.
Hematocrit is a measurement of the amount of space red blood cells occupy in your blood. A high hematocrit level might indicate dehydration. A low hematocrit level may indicate anemia. Abnormal hematocrit levels may also indicate a blood or bone marrow problem.
- MEAN CORPUSCULAR VOLUME:
Mean corpuscular volume (MCV) is a measure of the average size of your red blood cells. Abnormal MCV levels may be a sign of anemia or thalassemia.
2. Blood Chemistry Tests/Basic Metabolic Panel:
The basic metabolic panel (BMP) is a collection of assays that assesses several substances in the blood. These tests are often performed on the fluid (plasma) portion of the blood. Doctors can use the tests to learn about your muscles (including your heart), bones, and organs such as your kidneys and liver.
Blood glucose, calcium, and electrolyte tests, as well as blood tests to assess kidney function, are all part of the BMP. Some of these tests need you to fast (not eat anything) before taking them, while others do not. Your doctor will instruct you on how to prepare for the test(s).
- BLOOD GLUCOSE:
Glucose is a form of sugar that the body uses as an energy source. Diabetes can be detected by abnormal glucose levels in the blood.
Some blood glucose tests require you to fast before having your blood collected. Other blood glucose tests are performed immediately following a meal or at any time with no preparation.
Calcium is an important mineral in the body. Abnormal calcium levels in the blood may be a sign of kidney problems, bone disease, thyroid disease, cancer, malnutrition, or another disorder.
Electrolytes are minerals that assist the body regulate fluid levels and acid-base equilibrium. Sodium, potassium, bicarbonate, and chloride are among them.
Dehydration, renal illness, liver disease, heart failure, high blood pressure, and other conditions can all cause abnormal electrolyte levels.
Blood tests for kidney function assess blood urea nitrogen (BUN) and creatinine levels. Both of these are waste products that are removed from the body by the kidneys. BUN and creatinine levels that are abnormal may indicate a renal illness or problem.
3. Blood Enzyme Tests:
Enzymes are molecules that aid in the regulation of chemical processes in your body. There are several blood enzyme assays available. This section focuses on blood enzyme tests that are used to detect heart attacks. Troponin and creatine kinase (CK) assays are examples of these.
Troponin is a muscle protein that aids in the contraction of your muscles. Troponin seeps out when muscle or heart cells are harmed, and its levels in your blood rise.
When you suffer a heart attack, for example, your blood levels of troponin surge. As a result, doctors frequently prescribe troponin testing when patients complain of chest discomfort or other heart attack symptoms.
- CREATINE KINASE:
A blood product called CK-MB is released when the heart muscle is damaged. High levels of CK-MB in the blood can mean that you've had a heart attack.
4. Blood Tests To Assess Heart Disease Risk:
A lipoprotein panel is a blood test that can determine if you are at risk for coronary heart disease (CHD). This test checks for cholesterol-carrying molecules in your blood.
A lipoprotein panel gives information about your:
- Total cholesterol.
- LDL ("bad") cholesterol: This is the main source of cholesterol buildup and blockages in the arteries. (For more information about blockages in the arteries, go to the Diseases and Conditions Index Atherosclerosis article.)
- HDL ("good") cholesterol: This type of cholesterol helps decrease blockages in the arteries.
- Triglycerides: Triglycerides are a type of fat in your blood.
- A lipoprotein panel measures the levels of LDL and HDL cholesterol and triglycerides in your blood. Abnormal cholesterol and triglyceride levels may be signs of increased risk for CHD.
Most people will need to fast for 9 to 12 hours before a lipoprotein panel.
5. Blood Clotting Tests:
A coagulation panel is another name for blood clotting assays. These tests look for proteins in your blood that influence the clotting process. Abnormal test results may indicate that you are at risk of bleeding or getting blood clots in your veins.
If your doctor suspects you have a blood clotting issue or illness, he or she may offer these tests.
Blood clotting tests are also used to monitor persons who are receiving blood clot-lowering medications. Warfarin and heparin are two such medications.
What To Expect During Blood Tests?
What To Expect Before Blood Tests?
Many blood tests don't require any special preparation and take only a few minutes.
What To Expect During Blood Tests?
Other blood tests need fasting (no food) for 8 to 12 hours before to the test. Your doctor will instruct you on how to prepare for the blood test (s).
A needle is frequently used to take blood from a vein in your arm or another portion of your body. It can also be drawn using a finger prick.
The individual drawing your blood may ask you to create a fist or wrap a band over the top part of your arm. This causes the veins in your arm to protrude further, making it simpler to place the needle.
The needle that is inserted into your vein is connected to a little test tube. When the tube is filled, the individual drawing your blood removes it, and the tube closes on its own. After that, the needle is withdrawn from your vein. If you're having several blood tests, the needle may be linked to more than one test tube before it's withdrawn.
Some people are frightened of needles, thus they are anxious about blood tests. Others may object to seeing blood leave their bodies.
If you're frightened or terrified, you can divert yourself by looking aside or talking to someone. When the needle is inserted or removed, you may feel a minor sting.
Drawing blood usually takes less than 3 minutes.
What To Expect After Blood Tests?
After the needle is removed, you will be advised to apply light pressure to the area where the needle was entered using a piece of gauze or bandage. This helps to halt the bleeding. It also aids in the prevention of edema and bruising.
Most of the time, the pressure may be released after a minute or two. You might wish to apply a bandage for a few hours.
After a blood test, you usually don't need to do anything extra. The turnaround time for results might range from a few minutes to a few weeks. The results should be delivered to your doctor. It is critical that you follow up with your doctor to discuss the findings of your tests.
What Do Blood Tests Show?
Blood tests determine if the amounts of various chemicals in your blood are within a normal range.
The normal range for various blood chemicals is the range of values found in 95 percent of healthy persons in a certain population. Normal ranges for many tests vary based on your age, gender, ethnicity, and other variables.
For a variety of causes, your blood test results may fall outside of the usual range. Abnormal findings might indicate the presence of a problem or disease. Other variables, including as food, menstrual cycle, degree of physical activity, alcohol use, and medications (both prescription and over-the-counter), might also generate anomalous findings.
Any odd or abnormal blood test findings should be discussed with your doctor. These findings may or may not indicate a health concern.
Many illnesses and medical problems cannot be identified just by blood testing. Blood tests, on the other hand, can assist you and your doctor discover more about your health. Blood testing can also help detect possible issues early, when treatments or lifestyle modifications may be most effective.
Indications for Urine Test
A urinalysis is a common test that's done for several reasons:
- To evaluate your overall health: A urinalysis may be performed as part of a standard medical exam, a pregnancy checkup, or as part of pre-surgery preparation. When you're admitted to the hospital, it might be used to test for a range of illnesses, such as diabetes, renal disease, or liver disease.
- To determine the cause of a medical illness: If you experience stomach discomfort, back pain, frequent or painful urination, blood in your urine, or other urinary issues, a urinalysis may be ordered. A urinalysis can assist in determining the etiology of these signs and symptoms.
- To keep track of a medical condition: If you have a medical problem, such as kidney disease or a urinary tract infection, your doctor may advise you to test your urine on a regular basis to monitor your health and treatment.
- Other tests, such as pregnancy testing and drug screenings, might rely on a urine sample, but these tests look for substances that aren't included in a typical urinalysis.
Types and Findings of Urine test
Urine test strip:
A urine test strip can quantify:
Leukocytes – with presence in urine known as leukocyturia.
Nitrite – with presence in urine known as nitrituria.
Protein – with presence in urine known as proteinuria, albuminuria, or microalbuminuria.
Erythrocytes – with presence in urine known as hematuria.
Glucose - with presence in urine known as glucosuria.
Bilirubin - with presence in urine known as bilirubinuria.
Ketones - with presence in urine known as ketonuria.
The numbers and types of cells and/or material such as urinary casts can yield a great detail of information and may suggest a specific diagnosis.
Hematuria – associated with kidney stones, infections, tumors and other conditions.
Pyuria – associated with urinary infections.
Eosinophiluria – associated with allergic interstitial nephritis, atheroembolic disease.
Red blood cell casts – associated with glomerulonephritis, vasculitis, or malignant hypertension.
White blood cell casts – associated with acute interstitial nephritis, exudative glomerulonephritis, or severe pyelonephritis.
(Heme) granular casts – associated with acute tubular necrosis.
Crystalluria – associated with acute urate nephropathy (or acute uric acid nephropathy, AUAN).
Calcium oxalatin – associated with ethylene glycol, kidney stone disease.
Waxy casts – associated with chronic renal disease.
A microbiological culture of urine samples, detecting bacteriuria, is indicated when a urinary tract infection is suspected.
This tests for hemolysis in the blood vessels, a rupture in the capillaries of the glomerulus, or hemorrhage in the urinary system, which cause hemoglobin to appear in the urine.
What does urine test indicate?
Urine test results should always be interpreted using the reference range supplied by the laboratory that performed the test or information provided by the manufacturer of the test strip/device.
The following are examples of some urine colors and their causes (not a complete listing).
- Nearly colorless: Excessive fluid intake for conditions; untreated diabetes mellitus, diabetes insipidus, and certain types of nephritis.
- Yellow: Distinctly yellow urine may indicate excessive riboflavin (vitamin B2) intake.
- Yellow-amber: Normal.
- Yellow-cloudy: excessive crystals (crystalluria) and/or excessive pus (pyuria).
- Orange: Insufficient fluid intake for conditions; intake of orange substances; intake of phenazopyridine for urinary symptoms.
- Red: Leakage of red blood cells or of hemoglobin from such cells; hemolysis; intake of red substances.
- Reddish-orange: Intake of certain medications or other substances.
- Rusty-yellow to reddish-brown: Intake of certain medications or other substances.
- Dark brown: Intake of certain medications or other substances; damaged muscle (myoglobinuria due to rhabdomyolysis) from extreme exercise or other widespread damage, possibly medication related; altered blood; bilirubinuria; intake of phenolic substances; inadequate porphyrin metabolism; melanin from melanocytic tumors; presence of an abnormal form of hemoglobin, methemoglobin.
- Green, or dark with a greenish hue: Jaundice (bilirubinuria); problem with bile metabolism. Recent surgery requiring high doses of propofol infusion. The use of a medication (Uribel) that is similar to phenazopyridine for the relief of urinary symptoms.
- Other colors: Various substances ingested in food or drink, particularly up to 48 hours prior to the presence of colored urine.
Pee's odor (scent) can range from undetectable (when extremely light colored and dilute) to a significantly stronger stench when the patient is dehydrated and the urine is concentrated. Brief shifts in odor are typically purely amusing and have no medicinal significance. (For instance, many individuals notice an unusual odor after eating asparagus.) The urine of diabetics suffering from ketoacidosis (urine with high amounts of ketone bodies) may smell fruity or pleasant.
Ions and trace minerals:
- Nitrite-The presence of nitrites in urine, termed nitrituria, indicates the presence of coliform bacteria.
- Sodium (Na)- A urinalysis is frequently ordered during the workup of acute kidney injury. Full kidney function can be detected through the simple dipstick method.
- Potassium (K)- Urine K may be ordered as part of a hypokalemia workup. In the event of gastrointestinal K loss, urine K will be low. Urine K levels will be elevated in the presence of renal K loss. Low urine K levels are also found in hypoaldosteronism and adrenal insufficiency.
- Urinary calcium-An abnormally high level is called hypercalciuria and an abnormally low rate is called hypocalciuria.
Proteins and enzymes:
The Albustix test can be used to detect proteins. Proteins are very massive molecules (macromolecules) and are not generally present in quantifiable concentrations in glomerular filtrate or urine. Proteinuria, or the presence of protein in the urine, may suggest that the glomerulus' permeability has increased. This might be due to kidney infections or other disorders that have a secondary effect on the kidneys, such as hypertension, diabetes, jaundice, or hyperthyroidism.
Human chorionic gonadotropin (hCG)-This hormone is found in pregnant women's urine. It has also been found in cases of male testicular cancer. This chemical is frequently detected by home pregnancy tests.
Red blood cells (RBCs) /erythrocytes: If the RBCs are of renal or glomerular origin (due to glomerulonephritis), mechanical damage occurs during the glomerular transit, followed by osmotic damage throughout the tubules, resulting in dysmorphic characteristics. The dysmorphic RBCs in urine that are most distinctive of glomerular origin are known as "G1 cells," which are doughnut-shaped rings with projecting circular blebs that occasionally resemble Mickey Mouse's head (with ears).
Painless hematuria of nonglomerular origin might be a symptom of urinary tract cancer, necessitating a more complete cytological examination.
White blood cells (WBCs): "Significant pyuria" at greater than or equal to 10 leucocytes per microlitre (µl) or cubic millimeter (mm3)
Blood: Hemoglobinuria is indicative of in vivo hemolysis, although it should be separated from hematuria. In the instance of hemoglobinuria, a urine dipstick reveals the presence of blood but no RBCs on microscopic inspection. If hematuria is followed by artefactual ex vivo or in vitro hemolysis in the collected urine, the dipstick test will be positive for hemoglobin as well, making interpretation problematic. The color of the urine may also be red owing to the excretion of reddish pigments or medications.
Other urine parameters:
Urine specific gravity: The ion concentration of urine is detected by this test. Small levels of protein or ketoacidosis tend to raise the specific gravity of urine (SG). A urinometer is used to measure this value, which indicates hydration or dehydration. If the SG value is less than 1.010, the patient is hydrated; an SG value more than 1.020 suggests dehydration.
Osmolality: Urine osmolality testing can be used in conjunction with Plasma osmolality tests to confirm diagnosis of SIADH.
pH: Bacteriuria can be proven if a single bacterial species is recovered in clean-catch midstream urine specimens at a concentration more than 100,000 CFU/ml (one for men, two consecutive specimens with the same bacterium for women).
How Do I Prepare for a Urinalysis?
If the only test you're having is a urinalysis, you should be allowed to eat and drink normally before the procedure. Because beets and food colors might darken your urine, you should watch what you consume beforehand.
Make sure your doctor is aware of any medications you are taking, including over-the-counter medications, vitamins, and supplements. Let the doctor know if you're getting your period before the test.
You'll be asked to either collect a urine sample at home and bring it with you, or to do so in your doctor's office. The office will provide you with a container to hold the sample.
The best results come from using what’s known as the “clean catch” method. Here are the steps:
- Wash the area around the urinary opening.
- Start to pee into the toilet.
- Stop midstream.
- Let 1-2 ounces flow into the container.
- Finish peeing in the toilet.
- Follow your doctor’s directions for handing over the sample.
A doctor may have to place a soft, thin tube called a catheter through the urine hole and into the bladder for newborns and other persons who are unable to produce a sample in this manner.
Blood tests are one of the most prevalent forms of medical testing and have a wide variety of applications. A blood test can be used to monitor your overall health, detect infections, determine how effectively particular organs, such as the liver and kidneys, are functioning, and screen for certain hereditary diseases.
Most blood tests take only a few minutes to complete and are performed by a doctor, nurse, or phlebotomist at your GP clinic or local hospital (a specialist in taking blood samples).
A urinalysis may be performed as part of a normal check of your overall health, such as during your yearly physical. Urinalysis is one method for detecting some ailments in their early stages. They are Kidney disease, Liver disease, and Diabetes.
If you are about to undergo surgery or are about to be admitted to the hospital, your doctor may want to test your urine. Urinalysis can also be performed as part of a pregnancy checkup.
If you experience symptoms of a kidney or urinary tract disease, you may be given tests to assist determine the cause.
You may also get this test on a regular basis if you have a condition that has to be monitored over time, such as renal disease.