What Are Blood Tests?
Blood tests aid physicians in the diagnosis of specific diseases and conditions. Aside from that, they help determine the function of your organs and the effectiveness of treatments.
Medical professionals can benefit from blood tests in particular in the following ways:
- Evaluate the effectiveness of various organs, including the kidneys, liver, thyroid, and heart, among other things.
- Diagnose cancer, HIV/AIDS, diabetes, anemia (uh-NEE-me-eh), and coronary heart disease.
- You can find out if you are at risk for heart disease by taking this test.
- Check to see if the medications you are taking are effective.
- Decide about your blood’s ability to clot.
The use of blood tests is extremely common. When you visit your doctor for routine checkups, your doctor may recommend blood tests to assess the health of your organs and other bodily systems.
Hundreds of blood tests are non-invasive and require no special preparation on the part of the patient. For some tests, you may be required to fast for 8 to 12 hours prior to taking the examination. Your doctor will advise you on the best way to prepare for blood tests, which you should follow.
A blood test entails the removal of a small amount of blood from your body for testing purposes. It is typically obtained through the use of a needle inserted into a vein in your arm. An alternative method is the use of a finger prick.
The procedure is usually quick and painless, though some temporary discomfort may be experienced during the process. The vast majority of people do not experience any adverse side effects from having their blood drawn.
In laboratories, blood samples are drawn and analyzed (labs). They either count blood cells using whole blood or separate the blood cells from the fluid in which they are contained to count them separately. Plasma or serum are the terms used to describe this liquid.
The fluid’s concentration measures various substances in the blood to determine their concentration. According to the findings, early detection of health problems may aid in the development of more effective treatments or changes in lifestyle.
The diagnosis of many diseases and medical problems cannot be made solely based on blood tests. Your doctor may consider additional factors to confirm a diagnosis. These factors may include your symptoms and signs, your medical history, your vital signs (blood pressure, breathing, pulse, and temperature), as well as the results of other tests and procedures that you have undergone.
Blood tests are generally considered to be risk-free. The vast majority of complications are minor and disappear within a few hours of the tests being completed.
Following are a few of the most commonly performed blood tests:
- A complete blood count (CBC)
- Blood tests to determine a person’s risk of developing heart disease
- Blood enzyme tests
- Blood chemistry tests
Complete Blood Count
The complete blood count (CBC) is one of the most commonly performed blood tests, accounting for approximately one-third of all blood tests. It is frequently done as part of a routine physical examination.
Blood diseases and disorders such as anemia, infections, clotting problems, blood cancers, and immune system disorders can all be detected with the help of a complete blood count (CBC). As discussed in greater detail in the following paragraphs, this test measures various components in your blood.
RED BLOOD CELLS
Oxygen is transported throughout your body by red blood cells, which originate in your lungs and travel throughout your body. Blood tests that show abnormal red blood cell counts may indicate anemia, dehydration (inadequate fluid in the body), bleeding, or another medical condition.
WHITE BLOOD CELLS
White blood cells are an essential component of the immune system, and they are responsible for fighting infections and diseases in the body. Any increase in white blood cells may indicate an infection, blood cancer, or an immune system disorder.
When you have a complete blood count (CBC), it is possible to determine the total number of white blood cells present in your bloodstream. A differential complete blood count (CBC) is a test that looks at the proportions of different types of white blood cells in your blood.
Platelets (pronounced “PLATE-lets”) are fragments of blood cells that aid in the clotting process of the blood vessel walls. Because they adhere to one another, they can seal cuts or breaks in the blood vessel walls, effectively stopping blood flow.
Abnormal platelet counts may indicate a bleeding disorder (inadequate clotting) or a thrombotic disorder (insufficient clotting) (too much clotting).
Hemoglobin (HEE-much-glow-bin) is an oxygen-carrying protein found in red blood cells that helps function properly. In some cases, abnormal hemoglobin levels can indicate anemia, sickle cell anemia, thalassemia (pronounced thal-a-SE-me-ah), or other types of blood disorders.
Having diabetes causes excess glucose in the blood to bind to hemoglobin, which raises the hemoglobin A1c level in the bloodstream.
Hematocrit (pronounced hee-MAT-oh-crit) refers to the amount of space that red blood cells take up in your body’s blood. A high hematocrit level may indicate that the body is dehydrated. A low hematocrit value may indicate anemia. It is also possible that a high hematocrit level means a blood or bone marrow disorder.
MEAN CORPUSCULAR VOLUME
Red blood cells have an average size, measured by the mean corpuscular volume (MCV). In some cases, elevated MCV levels can indicate anemia or thalassemia.
Blood Chemistry Tests/Basic Metabolic Panel
In medicine, the basic metabolic panel (BMP) is a collection of tests used to determine various chemicals in the blood. These tests are often carried out on the fluid (plasma) component of blood. The tests can provide doctors with information about your muscles (including your heart), bones, and organs, such as your kidneys and liver, as well as your overall health.
In addition to blood glucose, calcium, electrolytes, and kidney function tests. A fast (meaning not eating anything) is required for some of these tests, whereas others do not require one to do so. Your doctor will provide you with instructions on preparing for the test(s) that you are scheduled to have.
A type of sugar known as glucose, which the human body uses as an energy source, is defined as follows: An abnormally high glucose level in the bloodstream may be a symptom of diabetes.
Specific blood glucose tests necessitate that you fast for some time prior to having your blood drawn. Other blood glucose tests can be performed immediately after a meal or at any time during the day, with no preparation required.
Calcium is a mineral that is essential for the human body. The presence of abnormally high calcium levels in the bloodstream may indicate kidney disease, bone disease, thyroid disease, cancer, malnutrition, or another type of disorder.
Electrolytes are minerals that help to maintain the body’s fluid balance as well as its acid-base equilibrium. Examples include sodium, potassium, bicarbonate, and chloride, to name a few.
The presence of electrolyte imbalances can indicate various conditions such as dehydration, kidney disease, liver disease, heart failure, or high blood pressure.
Blood tests for kidney function are used to determine urea nitrogen (BUN) and creatinine levels in the blood (kre-AT-ih-neen). The kidneys are responsible for excreting both of these substances. Elevated levels of BUN and creatinine may be indicators of kidney disease or dysfunction.
Blood Enzyme Tests
Enzymes are substances that aid in regulating chemical reactions in the body and are found in all living organisms. There are a plethora of blood enzyme tests available. During this section, you will learn about blood enzyme tests used to detect heart attacks in the body. For instance, the troponin and creatine kinase (KRE-ah-teen) tests are two examples.
Troponin is a type of muscle protein involved in the contraction of the muscles in your body. Troponin is released when muscle or heart cells are injured, increasing the amount of the hormone in the blood.
Following a heart attack, for example, the blood level of troponin rises significantly higher. As a result, doctors frequently order troponin tests when patients present with chest pain or other signs and symptoms of a heart attack.
Damage to the heart muscle causes the release of a blood product known as CK-MB (CK-MB). You may have had a heart attack if your CK-MB levels are elevated in the blood.
Blood Tests To Assess Heart Disease Risk
A lipoprotein panel is a type of blood test that can be used to determine whether or not you are at risk of developing coronary artery disease (CHD) (CHD). When you take this test, the substances in your blood that carry cholesterol are examined.
Among the information provided by a lipoprotein panel is information regarding your:
- Total cholesterol.
- “Low-density lipoprotein” (“bad”) cholesterol. Increasing cholesterol levels and artery blockages are the primary causes of these conditions. The Diseases and Conditions Index article on atherosclerosis provides additional information on arterial blockages.
- High-density lipoprotein (“HDL”) cholesterol. Specifically, this type of cholesterol contributes to the reduction of arterial blockages.
- Triglycerides. In your blood, triglycerides are a type of fat.
A lipoprotein panel tests your blood for levels of LDL and HDL cholesterol, as well as triglycerides, to determine your overall health. Abnormally high cholesterol and triglyceride levels may indicate a higher risk of coronary heart disease.
The vast majority of people must fast for 9 to 12 hours before having a lipoprotein panel performed on them.
Blood Clotting Tests
In some cases, the term “coagulation panel” (pronounced “Ko-ag-yu-LA-shun”) is used to refer to blood clotting tests. These tests look for proteins in your blood that could be interfering with the clotting process and should be avoided. The presence of abnormal test results may indicate that you are at risk of bleeding or that blood clots are forming in your blood vessels.
If your doctor suspects that you have a blood clotting disorder or disease, they may recommend that you undergo these tests.
Aside from that, blood clotting tests are used to monitor patients who are taking blood clot-preventive medications. Warfarin and heparin are two examples of such medicines.
What To Expect When It Comes To Blood Tests
There are a variety of blood tests that are non-invasive and only take a few minutes.
Other blood tests necessitate a fast of 8 to 12 hours before the examination. Your doctor will give you specific instructions on how to prepare for the blood test (s).
How To Prepare For Blood Tests
According to standard procedure, blood is typically drawn from a vein in your arm or other parts of your body using a needle. Additionally, it can be removed by pricking the skin with a finger.
The person drawing your blood may tie a band around your upper arm or ask you to make a fist before starting the procedure. This may cause the veins in your arm to protrude more, making needle insertion more difficult.
The needle inserted into your vein is attached to a small test tube used to collect samples. When the tube is empty, the person drawing your blood removes it, and the tube automatically seals itself shut. After that, the needle is carefully removed from your vein and disposed of. Depending on how many blood tests you have scheduled, the needle may be attached to more than one test tube before it is withdrawn.
Some people experience anxiety during blood tests due to a fear of needles, which is understandable. Others may object to the sight of their blood being expelled from their bodies.
Distracting yourself by looking away or conversing with someone can help you relax and become less nervous or afraid. You may experience a slight stinging sensation when the needle is inserted or removed.
It usually takes less than three minutes to collect blood samples.
What You Can Expect Following Blood Tests
If you are asked to gently press the area where the needle was inserted with a piece of gauze or bandage after the needle has been removed, you will be asked to do so. This aids in the cessation of bleeding. Furthermore, it aids in the prevention of swelling and bruising after a traumatic injury.
You should be able to release the pressure after a minute or two, on average. You may want to leave a bandage in place for several hours.
Most of the time, you will not be required to do anything else following a blood test. The appearance of results can take anywhere from a few minutes to several weeks, depending on the circumstances. The results should be forwarded to your physician. You must schedule an appointment with your doctor to discuss the results of your tests.
What Are the Possible Consequences of Blood Tests?
The most common risks associated with blood tests are discomfort and bruising at the needle injection site. These complications are usually minor and disappear within a few hours of the tests being completed.
What Are the Results of Blood Tests?
Blood tests are used to determine whether or not the levels of various substances in your blood are within the normal range of concentrations.
Typically, the normal range is defined as the range of values observed in 95 percent of healthy individuals in a given group for a given blood substance. For many tests, the typical ranges vary depending on your age, gender, race, and other factors, among other things.
There are a variety of reasons why your blood test results may be abnormal. In some cases, abnormalities in the results may be indicative of a disorder or disease. Besides diet and menstrual cycle, other factors such as level of physical activity, alcohol consumption, and medication use (both prescription and OTC) can all play a role in producing abnormal results.
Blood test results that are out of the ordinary or abnormal should be discussed with your doctor. Depending on the results, they may or may not indicate the presence of a health problem, such as diabetes or high blood pressure.
The diagnosis of many diseases and medical problems cannot be made solely based on blood tests. On the other hand, blood tests can be beneficial to you and can assist your doctor in learning more about your health. Aside from that, blood tests can aid in the identification of potential problems at an early stage, when treatments or lifestyle modifications may be most effective.
Result Ranges for Common Blood Tests
A discussion of normal ranges for several of the most frequently performed blood tests is provided in this section.
Please keep in mind that all of the values in this section are only intended for adults. They do not apply to children under the age of majority. For information on blood test values for children, speak with your child’s doctor.
Complete Blood Count
Various components of the complete blood count (CBC) test have normal ranges, summarized in the following table. Men and women are assigned to different regular fields in different situations. Age and race, among other factors, may have an impact on normal ranges.
Your doctor should sit down with you and go over the results. if your results fall outside of the normal range for your group, you will be contacted and given additional instructions
According to the following table, after 8 to 12 hours of fasting, the blood glucose ranges are as follows: (not eating). This chart shows the normal range and the abnormal ranges associated with prediabetes or diabetes.
Following a fast of 9 to 12 hours, the total cholesterol, LDL (“bad”) cholesterol, and HDL (“good”) cholesterol levels should be within normal ranges, as shown in the table below. An elevated cholesterol level in the blood is associated with an increased risk of developing coronary heart disease.
Your physician should discuss the results of your tests with you. They will get in touch with you if your results fall outside of the expected range.