All About Lab Tests
Lab tests are a sort of tool commonly used by medical professionals. They can be used to identify a disease or a potentially harmful medical condition. These tests are usually applied to blood or urine taken from the patient. However, they can be applied to tissues or other organic matter removed from the patient. It depends entirely on the nature of the test and what the doctor is attempting to diagnose.
The actual testing very rarely occurs in the hospital. Instead, the sample taken from the patient is sent to a partnering laboratory for testing. What is revealed during the testing will depend on the sample, the type of testing, and what is being tested for. The test could be used for various reasons, such as:
– Identify a particular disease or medical condition.
– Gauging how well the body is responding to a particular treatment.
– Monitor changes in a disease that has existed for a period of time.
– Determine if a patient can use a particular treatment.
– Test for a health condition prior to symptoms appearing.
When the tests are sent to the laboratory, the professionals there are provided with specific instructions. They know what tests to perform and what it is they are looking for. They are often looking to see if the provided sample includes some specific substance and how much of it. That substance can determine if a person is suffering from a disease or if their body is responding to treatment as it should.
Decades of collecting data and performing medical studies have provided doctors with something called normal ranges. Ideally, a lab test should return with a value that falls within this normal range. That value relates to the quantity of the substance that exists within the sample. This process doesn’t apply to 100 percent of lab tests, but it does for many of them.
The Coombs test is a great example of this process. Blood is the sample removed from the patient to be tested and the substances being tested for are specific antibodies. While antibodies are usually a good thing, there are some diseases that cause these antibodies to attack your own red blood cells.
The Coombs test looks for those antibodies by checking the sample for antibodies that are attached to red blood cells. There isn’t exactly a “normal range” for this test. Rather, the test results from a normal individual would reveal red blood cells without antibodies. If the test reveals blood cells with antibodies attached, then it is very likely the patient is suffering from a serious health condition.
The Coombs test is only one of the many different lab tests a doctor may administer. Here are just a few more.
Cholesterol Blood Testing
Cholesterol is directly related to numerous health conditions. A cholesterol blood test can help determine the amount of the different cholesterol types that exist in your bloodstream. This will help identify your risk for suffering from related health conditions, such as stroke or cardiovascular disease. The “normal range” for this test is usually between 180 to 200 mg/dL for total cholesterol. That range can sometimes vary according to certain factors. For example, patients with existing heart conditions will have a different range.
Blood is the sample provided by the patient for this test. The substances being tested for are all cholesterol types. Some tests also screen for triglycerides as well. Most tests will clearly identify the ratio of the different cholesterol types, such as LDL, HDL, and VLDL. However, there are some that only determine the amount of total cholesterol in the blood without identifying ratios.
The first test administered by the doctor is often a total cholesterol test. It’s recommended that everyone have this test once they’ve reached the age of 35. If the total cholesterol level does not fall within the normal range, then the doctor will recommend a more comprehensive test to identify the ratio of different types of cholesterol in the blood. Follow tests are recommended every few years as well.
Complete Blood Count Testing
A complete blood count(CBC) test is an extremely common procedure that can identify a number of potential health conditions. The CBC provides doctors with information regarding the different blood cells in the body and their quantities. It can be used to determine if there has been any increase or decrease in the amount of those blood cells over time. Some of the conditions that can be diagnosed with the help of a CBC include:
– Heart disease
– Autoimmune diseases
The test itself isn’t a definitive diagnosis, but rather it is used in conjunction with the information the doctor has available. The test simply reveals if the counts for certain blood types are too low or too high. If they are either of these, then the doctor may order additional tests to check for specific conditions.
A CBC may be recommended by your doctor during a regular checkup. It’s not reserved specifically for when you are experiencing symptoms. It can help identify diseases before symptoms appear, which helps doctors provide the best possible treatment. The test should reveal:
– Platelet counts
– Hemoglobin amounts
– Red blood cell count
– White blood cell count
– Hematocrit percentage
These numbers can provide doctors with a general snapshot of your health. That’s why they are one of the most commonly performed lab tests in the country. Everyone should have one performed and they should be repeated on a regular basis.
Preparing For Lab Tests
Most lab tests don’t require extensive preparation. For example, the tests above require only that you wear a short sleeve shirt and be prepared to give a small amount of blood. There are some tests that will require a period of fasting or some additional steps. The doctor will discuss these requirements with you if there are any.
After the sample is removed the doctor sends it to the lab, the test is performed, and the doctor shares the results with the patient. This can take as little as a few days or as long as a few weeks depending on the test type and the location of the lab.