Regular checkups may detect early warning signals of health problems. Early detection of diseases increases the likelihood of successful treatment. Numerous variables, including your age, health, family history, and lifestyle choices, influence how often you require checkups. General health examinations that provide a clear picture of your health. For that one may also be advised to go for a lab test. Several lab tests are customized for a specific condition or set of disorders. Other tests are often used to diagnose a broad variety of illnesses. In this article, we will be discussing some common lab tests that may be prescribed to you by your doctor.
What Are Lab Tests?
Medical lab tests employ chemical methods to determine the concentrations of chemical substances in bodily fluids and tissues. Numerous tests exist to identify and quantify almost every chemical component in blood or urine. Blood glucose, electrolytes, enzymes, hormones, lipids (fats), other metabolic components, and proteins may be constituents. Lab tests are conducted for a number of purposes, including the following:
- Diagnosing a condition.
- Evaluation of the severity of a condition in order to plan treatment.
- Monitoring the treatment’s efficacy.
Less commonly, sweat, saliva, and fluids from the digestive tract (such as gastric secretions) are tested. Sometimes the fluids tested are present only if pathology is present, such as when fluid gathers in the belly, generating abscesses. Normal test ranges are based on healthy population averages. 95% of healthy adults have these levels. Averages vary by gender and age. When physicians acquire a lab test result, the lab provides them with its typical range. Normal outcomes are listed below. Because lab values vary, it is always advisable to consult your physician about your health so they prescribe the appropriate test for you.
Lab Tests for Diabetes.
One will require a blood sugar test to determine if you have prediabetes, type 1, type 2, or gestational diabetes. Generally, testing is quick and findings are readily accessible. Your doctor will prescribe one or more of the blood tests listed below to confirm the diagnosis of diabetes.
- A1Test. The hemoglobin A1C test, commonly known as the HbA1c test, is an easy blood test that examines the average blood glucose levels over the preceding three months. Another name for this test is the A1C test. It is not only the primary test that will assist you and your health care team in managing your diabetes, but it is also one of the most frequent tests that are used to detect prediabetes and diabetes.
- Glucose Tolerance Test. This tests blood sugar before and after drinking the glucose. Before the test, you’ll fast overnight and have blood collected to measure your fasting blood sugar. After drinking the beverage, your blood sugar will be tested 1 to 3 hours later.
- Random Blood Sugar. This determines your blood sugar level at the time of testing. You may take this examination at any time and are not required to fast beforehand. If your blood glucose level is 200 mg/dL or greater, you probably have diabetes.
The following table summarizes the normal ranges to diabetic ranges for these lab tests.
|A1C Test||Fasting Blood Sugar Test||Glucose Tolerance Test||Random Blood Sugar Test|
|Normal||Below 5.7%||99 mg/dL or below||140 mg/dL or below||N/A|
|Prediabetes||5.7 – 6.4%||100 – 125 mg/dL||140 – 199 mg/dL||N/A|
|Diabetes||6.5% or above||126 mg/dL or above||200 mg/dL or above||200 mg/dL or above|
Lab Tests for Cholesterol.
A full cholesterol test, also known as a lipid panel or lipid profile, is a blood test that measures the levels of cholesterol and triglycerides in your blood. Our body produces sufficient cholesterol, but if exceeded, it can accumulate in the arteries, causing them to become hard and leading to atherosclerosis. That is why healthcare practitioners use lipid panels for children and adults to assess the risk of cardiovascular disorders such as heart disease, heart attack, and stroke. A full cholesterol test measures four kinds of blood fats:
- High-Density Lipoprotein (HDL). HDL cholesterol is referred to as the “good” cholesterol because it aids in the removal of LDL cholesterol.
- Low-Density Lipoprotein (LDL). This is the “bad cholesterol,” which is the main cause of plaque buildup, which makes you more likely to get heart disease. In general, the better it is if the number is lower. Recent recommendations advocate a set percentage of LDL reduction depending on a person’s total risk to avoid heart and vascular issues.
- Triglycerides. Your body breaks down fats into triglycerides when you consume them. Triglycerides raise the risk of cardiovascular disease. Obesity, uncontrolled diabetes, excessive alcohol use, and a high-calorie diet may raise triglyceride levels.
- Very Low-Density Lipids (VLDL). Another kind of “bad” cholesterol is very low-density lipoprotein (VLDL). High VLDL levels cause arterial plaque. VLDL is difficult to assess and isn’t included in normal cholesterol testing. Your VLDL level may be approximated as a proportion of your triglycerides.
- Total Cholesterol. This is the total cholesterol level in your blood. It is the combination of LDL, HDL, and VLDL cholesterol. Total cholesterol and HDL cholesterol are the only directly measured amounts. Whereas, VLDL and LDL are calculated on the basis of total cholesterol, HDL, and Triglycerides levels.
If your doctor suggests a “non-fasting” cholesterol test, the lab will merely check your total cholesterol (and potentially HDL). For the test, you only need to provide blood. If your doctor recommends a “fasting” cholesterol test, the lab will assess your LDL, HDL, triglycerides, and total cholesterol. Before the blood test, fast for 9 to 12 hours. Ideal results for most adults are as follows,
Liver Panel Test.
A liver function panel is a blood lab test that evaluates the health of the liver. Liver function tests measure the concentrations of certain enzymes and proteins in the blood such as the total protein, albumin, bilirubin, and liver enzyme levels. High or low levels may indicate the presence of liver injury or illness. If anyone shows symptoms of liver illness, the doctor may prescribe a liver function test. The following components will be calculated in it,
- Alanine transaminase (ALT): ALT is an enzyme present in the liver that facilitates the conversion of proteins into energy for liver cells. ALT is secreted into the circulation and levels rise when the liver is injured.
- Aspartate transaminase (AST): AST is an enzyme that helps amino acids get used up in the body. Like ALT, AST is usually found in low amounts in the blood. If AST levels go up, it could be a sign of liver damage, disease, or muscle damage.
- Alkaline phosphatase (ALP): Breaking down proteins requires the enzyme ALP, which may be present in both the liver and bone. ALP levels that are higher than usual may be indicative of liver illness or injury, such as a blocked bile duct or certain bone disorders.
- Gamma-glutamyl transferase (GGT): The enzyme GGT is found in the body’s fluids. The presence of higher-than-average levels may suggest liver or bile duct injury.
- L-lactate dehydrogenase (LD): The liver is home to the enzyme LD. Increased levels may suggest liver injury, but they may also be elevated in a variety of other conditions.
- Prothrombin Time: The PT is the time required for the blood to clot. It’s possible that a high PT is a sign of liver damage, but it may also happen if users are on blood thinners like warfarin.
- Albumin and total protein: The liver produces a variety of proteins, including albumin. These proteins are required by the body to combat infections and carry out a variety of other tasks. Albumin and total protein levels that are lower than normal may suggest liver injury or illness.
- Bilirubin: It is a chemical created during normal red blood cell disintegration. The liver processes bilirubin and excretes it in the stools. Its high level indicates that the liver has been damaged or diseased or that certain forms of anemia are present when bilirubin levels are elevated (jaundice).
Normal liver function tests include the following results:
|ALT.||7 to 55 units per liter (U/L)|
|AST.||8 to 48 U/L.|
|ALP.||40 to 129 U/L.|
|GGT.||8 to 61 U/L|
|LD.||122 to 222 U/L|
|PT||9.4 to 12.5 seconds|
|Albumin & total protein||3.5 to 5.0 grams per deciliter (g/dL). 6.3 to 7.9 g/dL|
|Bilirubin||0.1 to 1.2 milligrams per deciliter (mg/dL)|
C-Reactive Protein Lab Test.
A high CRP blood level might be indicative of inflammation. It may be caused by a vast range of illnesses, from infection to malignancy. This test may indicate a high amount of inflammation, but it does not indicate the location or cause of the inflammation. This lab test requires no preparation. One may eat normally and take the test at any time. This test requires a tiny needle to draw blood,
|A typical result||Less than 10 mg/L|
|A high result:||Equal to or greater than 10 mg/L|
A test for high-sensitivity C-reactive protein (hs-CRP) differs differently from a standard C-reaction protein test. Typically, this test predicts cardiovascular disease and stroke. In contrast to the conventional C-reactive test, which measures high protein levels, the hs-CRP test detects lower (but still increased) protein levels. Doctors will only prescribe this test if they are focusing only on the cardiovascular health of a person. It shows the following results,
A calcium blood work measures the concentration of calcium in the blood. Calcium is one of the most essential nutrients in your body. Calcium is necessary for healthy bones and teeth. Calcium is also essential for the health of neurons, muscles, and the heart. The bones contain % of the body’s calcium. The remaining 1% circulates via the circulatory system. Too much or too little calcium in the blood may indicate bone, thyroid, cancer, or renal problems.
- Total calcium quantifies the calcium bound to certain blood proteins.
- Ionized calcium quantifies calcium that is “free” of these proteins.
Total calcium is often measured as part of a standard screening test known as a basic metabolic panel. A basic metabolic panel is a blood test that detects calcium together with other minerals and chemicals. Learn more about it and other methods of screening and physical examination here.
Your healthcare professional will collect blood from your arm to complete the lab test. You may or not be asked to fast before it. Normal adult blood calcium levels are:
|Total blood calcium:||8.5 to 10.5 milligrams per deciliter (mg/dL)|
|Ionized calcium:||4.65 to 5.2 mg/dl|
Vitamin D Tests.
Vitamin D testing is used to detect and track bone diseases. It is also occasionally used to measure vitamin D levels in persons with chronic disorders such as asthma, psoriasis, and certain autoimmune conditions. If you exhibit signs of vitamin D deficiency, the healthcare professional may have recommended a vitamin D test (not enough vitamin D). These symptoms consist of bone weakness, bone softness, frequent fractures, and bone malformations in the case of children. A routine blood test is required for a vitamin D assessment. The reference range is as given.
|Deficiency||less than 30 nmol/L (12 ng/mL)|
|Potential Deficiency||between 30 nmol/L (12 ng/mL) – 50 nmol/L (20 ng/mL)|
|Normal Levels||between 50 nmol/L (20 ng/mL) – 125 nmol/L (50 ng/mL)|
|High Levels.||higher than 125 nmol/L (50 ng/mL)|
Results will vary according to age, gender, and testing methodology. Results might also vary somewhat across laboratories. If the vitamin D levels are low and you are experiencing bone discomfort, your doctor may prescribe a bone density scan. Most of the time, excessive use of vitamin pills and other nutritional supplements results in elevated blood levels of vitamin D. Hypervitaminosis D is a disorder that may occur when too much vitamin D is consumed. Hypervitaminosis is an uncommon but significant illness that increases the likelihood of developing liver or renal issues.
Vitamin B-12 (Folate) Testing.
Folic acid testing analyses folic acid levels in the blood. A folic acid is a synthetic form of vitamin B9. Folate is the name of vitamin B9 in its natural state. Folic acid is required for the production of red blood cells (RBC), white blood cells (WBC), and platelets, as well as for appropriate development. Folic acid is also essential for a baby’s optimal growth (fetus).
This lab test is carried out to seek the causes of anemia, malnutrition, or malabsorption, and for pregnant woman’s folic acid levels. For the folic acid blood test, one must avoid food and drink (with the exception of water) for eight to ten hours before the actual test. The typical range is between 2.7 and 17.0 nanograms per milliliter or 6.12 and 38.52 nanomoles per liter.
An electrolyte test, also known as a serum electrolyte test, is a lab test that examines whether or not the body has an electrolyte imbalance. Blood electrolytes include sodium, potassium, chloride, and bicarbonate. They are capable of conducting electrical impulses inside the body. Electrolytes are necessary for maintaining fluid balance in the body and regulating one’s heart rate and rhythm, bone and dental health promotion, and providing support for nerve and muscle function, also lowering blood pressure. The test may be performed during a standard physical examination or as part of a more extensive number of lab tests.
- Sodium: aids in regulating the body’s fluid balance. As a result, the nerves and muscles are better able to perform their functions.
- Potassium: aids in good cardiac and muscle function
- Chloride: also regulates bodily fluids. It maintains blood volume and pressure.
- Magnesium: enhances nerve and muscle function and bone and tooth development.
- Phosphate: supports the development of healthy teeth and bones, as well as nerve and muscular function.
- Bicarbonate: helps maintain the acid-base balance of the body. Additionally, it serves a crucial function in transporting carbon dioxide throughout the circulation.
These are the typical electrolyte ranges.
|Sodium:||136 to 144 mmol/L.|
|Potassium:||3.7 to 5.1 mmol/L.|
|Chloride:||97 to 105 mmol/L.|
|Magnesium:||1.7 to 2.2 mg/dL.|
|Phosphate:||2.5 to 4.8 mg/dL.|
|Bicarbonate:||22 to 30 mmol/L.|
High blood pressure, renal illness, and a life-threatening abnormality in the heart’s rhythm may all be indicated by abnormally low levels of these electrolytes.
Having iron in your body is not the same as having ferritin. Ferritin, on the other hand, is a protein that accumulates iron and releases it when needed by the body. Only a small amount of ferritin is found in the bloodstream since most of it is stored in the cells. If your physician feels that you have an iron insufficiency or iron excess, he or she may perform a ferritin test. This test examines the amount of iron stored in your body, providing your physician with an overall picture of your iron levels. The lab test is sometimes requested in conjunction with other iron-related tests, such as an iron level or a total iron-binding capacity (TIBC) test.
A ferritin level that is lower than normal may suggest an iron deficiency and high levels are the indicators of hemochromatosis (body absorbing more than sufficient iron), rheumatoid arthritis, leukemia, and hypothyroidism.
Total Iron Binding Capacity Test.
Total iron-binding capacity (TIBC) is a blood test used to determine whether a person’s blood contains too much or too little iron. Transferrin, a protein, transports iron throughout the blood. This test informs the healthcare practitioner of the protein’s ability to transport iron in the blood. The doctor may suggest this test if anyone exhibits anemia symptoms due to iron deficiency. As transferrin is generated by the liver, the liver illness will also reduce your TIBC level.
The normal value range is,
|Iron:||60 to 170 micrograms per deciliter (mcg/dL)|
|TIBC:||240 to 450 mcg/dL|
|Transferrin saturation:||20% to 50%|
TIBC is often elevated when the body’s iron stores are depleted. This might occur in iron deficiency anemia and late pregnancy. Lower than normal is indicative of anemia, malnutrition, liver diseases, and inflammation.
To get a complete insight into which tests one should go to in their 20s and 30s etc., please refer to our article.
Uric Acid Test.
The purpose of a uric acid lab test is to measure the quantity of a normal waste product in the blood or urine. This lab test is also known as a serum urate (SU) or uric acid level test. It may be an essential diagnostic and therapeutic tool for gout and kidney stones.
Higher amounts of uric acid might cause health problems. Hyperuricemia has several causes. Kidney illness, some blood malignancies, metabolic errors, hypothyroidism, psoriasis, rhabdomyolysis, hemolytic anemia, certain drugs, and a purine-rich diet may cause it. It may be an issue if many cells are broken down (producing purines) or if purines are difficult to remove.
A tiny needle is used to draw blood from an arm vein during a blood test. A tiny quantity of blood is taken once the needle is inserted. For a uric acid urine test, one must collect all urine passed over the course of 24 hours. This is known as a 24-hour urine test.
Uric acid levels might vary according to gender. Normal ranges are
|Women||1.5 to 6.0 mg/dL|
|Men||2.5 to 7.0 mg/dL,|
However, the results may vary depending on the testing laboratory.
Culture Lab Tests.
Bacteria are microscopic creatures with a single cell. They have many sizes and shapes and cover almost every part of the body. Bacteria may be harmful or even beneficial depending upon the type. Others may be the source of disease-causing pathogens. A bacteria culture test may help identify pathogenic bacteria on or inside the body that may be causing illness. One will need to provide a sample of your blood, urine, skin, or other tissue for the test. The kind of sample depends on the suspected location of the illness.
Certain forms of diseases are diagnosed with the use of bacterial culture testing. Bacterial testing and its applications are the most common and are given below.
- Throat Culture. A throat culture is a diagnostic procedure used to detect bacterial or fungal infections in the throat. The Sample of mucus is taken from the back of the throat and tonsils are swabbed using a special swab.
- Sputum Culture. Sputum is a viscous secretion that forms when bacteria or fungus multiply in the lungs or bronchi. A sputum test, also known as a sputum culture, is a test that a doctor may recommend if you have an infection of the respiratory tract or another lung-related condition to discover what is developing in the lungs. The sample is taken in a specialized sterilized cup with saliva or by bronchoscopy (in rare cases)
- Urine Culture. A urine culture is a lab test that detects bacteria and other microorganisms in a urine sample. It may be used to test adults and children for urinary tract infections. For sample purposes, one is required to follow the provided directions carefully and hand over a container containing a clean sample of urine.
- Blood Culture. A blood culture is a lab test that detects the occurrence of disease-causing bacteria and fungus in blood samples. A blood sample is put in a specific container in a laboratory and observed to determine whether or not bacteria proliferate. Typically, a health care worker draws blood from a vein in the arm for taking samples.
- Stool Culture. This test detects and identifies bacteria that cause diseases in the lower digestive system. The test differentiates between disease-causing (pathogenic) and non-pathogenic (usually present in the digestive system) microorganisms. Sample collection is similar to that of urine culture.
- Wound Culture. The purpose of a skin or wound culture is to identify infectious organisms (such as bacteria or fungi) that may cause an infection. A doctor uses a swab to collect wound cells or pus. Deeper wounds may need a syringe to extract fluid or a biopsy to remove tissue.
The sample will be sent to a laboratory where bacteria cells will be cultivated until sufficient for testing. Typically, test results are available within a few days. However, certain varieties of bacteria grow slowly, so it may take several days or more to get results. Some disease-causing bacteria require five days or more to generate enough cells for testing. The following timetable is usually referred to for the waiting time of cultures.
|Throat Culture||can take 2 to 5 days|
|Sputum Test||may take from 1 day to several weeks.|
|Urine Culture||1 to 3 days|
|Blood Culture||at least 48 to 72 hours,|
|Stool Culture||within 24 to 48 hours|
|Wound Culture||may take from 1 day to several weeks,|
If no microorganisms are present, the culture is negative. If infectious microorganisms develop, the culture is positive. A positive blood culture indicates a bacterial or yeast infection. Results assist the doctors to identify the infection-causing bacteria or fungus.
In order for your lab results to be accurate and reliable, the patient plays a significant role. In the end, the test will be done on a sample taken from the body (blood, urine, or another specimen. To guarantee that the findings are meaningful and appropriately interpreted by the healthcare professional, you must perform the following:
- Tell your doctor about any drugs you are taking, including vitamins and supplements.
- It’s a good idea to keep track of the times you take prescription drugs, such as anticoagulants (blood-thinners) or seizure medication, as well as the times your blood is taken.
- Many lab tests don’t need prep. If so, follow the instructions. If you’re unsure about the instructions, ask the physician.
- Fasting for many hours or overnight is common to test preparation. Some tests ask you to increase or reduce your drinking by 10 to 12 hours beforehand.
You could be worried about the results of a medical test. Medical lab testing is generally beneficial in diagnosing. But it is important to keep in mind that no one diagnostic test can be relied upon to provide a diagnosis alone. So your medical history, age, gender race, and environmental factors play an important role along with lab testing.
As with other parts of medical treatment, it is vital that people remain open and honest with the healthcare practitioner about lab tests. In addition to providing your entire personal, medical, and family history, you may need to report any deviations from preparation instructions and/or drugs, including vitamins and supplements, that you are taking at the time of testing, since they may alter the findings. You may also be questioned about the quantity of alcohol you drink, the number of cigarettes you smoke, and any illegal substances you may have recently consumed. Providing comprehensive and correct information will assist in guaranteeing that your test findings are reliable and that you get a fast diagnosis and/or treatment.