Waiting for blood test results can be stressful, especially when you are not sure how long the laboratory will take to process your sample. Some blood tests can be completed within a few hours, while others may take several days depending on the type of test, the laboratory process involved, and whether the sample needs to be sent to another facility.
Understanding the factors that affect turnaround time can help you know what to expect after having your blood collected.
If you are preparing for a blood test, it is also useful to understand that the time it takes to collect your sample is usually much shorter than the time required to analyse it and release a verified result.
How Long Do Blood Test Results Usually Take?
There is no single turnaround time for every blood test. The expected time depends mainly on the type of analysis being performed.
Some routine tests may be completed on the same day, while more specialised investigations can take longer.
For example, a laboratory may process tests such as:
- Full Blood Count (FBC)
- Blood glucose
- Blood group
- Cholesterol or lipid profile
- Some liver function tests
- Some kidney function tests
within a relatively short period.
More specialised tests, including certain hormone, genetic, microbiological, molecular, or advanced analytical investigations, may require additional processing and therefore take longer.
This is why it is important to ask the laboratory for the estimated turnaround time for the specific test you are taking.
Why Do Some Blood Tests Take Longer Than Others?
Blood testing involves more than simply putting a sample into a machine.
Depending on the investigation, the laboratory may need to:
- Receive and register the sample.
- Check the sample and patient information.
- Prepare the specimen for analysis.
- Perform the required laboratory procedure.
- Review the analytical results.
- Carry out quality-control checks.
- Have the result reviewed or authorised before release.
A simple test may move through these stages quickly, while a specialised investigation may require additional procedures or equipment.
7 Factors That Can Delay Blood Test Results
Even when a laboratory provides an expected turnaround time, certain circumstances can cause results to take longer.
1. The Type of Test
The biggest factor is usually the test itself.
A routine blood test may be processed using equipment available within the laboratory, while specialised tests may require more complex procedures, specialist equipment, or additional verification.
For example, a routine FBC and a specialised DNA analysis should not be expected to have the same turnaround time.
2. Sample Preparation
Some samples require preparation before analysis.
The laboratory may need to separate components of the blood, prepare the specimen for a particular instrument, or carry out other procedures before testing can begin.
The more preparation a test requires, the more this can affect the overall turnaround time.
3. Sample Quality
A blood sample must be suitable for the test being requested.
Problems such as insufficient sample volume, contamination, clotting where it should not occur, haemolysis, or incorrect sample collection can affect testing.
In some situations, the laboratory may need another sample before the test can be completed.
This is one reason proper sample collection and handling are important.
4. High Laboratory Workload
Laboratories process many samples every day. During particularly busy periods, the number of samples waiting for processing can affect turnaround time.
This does not necessarily mean that anything is wrong with your sample. It may simply mean that the laboratory is handling a larger workload than usual.
5. Equipment or Technical Issues
Laboratory instruments require regular maintenance and quality checks.
If an analyser requires maintenance, calibration, troubleshooting, or technical attention, some tests may temporarily take longer to complete.
Laboratories may also have backup procedures for certain situations, but these can sometimes affect turnaround time.
6. Samples Sent to Another Laboratory
Not every laboratory performs every type of test in-house.
A sample may sometimes need to be transported to another laboratory with the appropriate equipment or expertise.
When this happens, transportation, receiving, testing, verification, and reporting can all contribute to a longer turnaround time.
7. Additional Result Verification
Some results may require additional review before they are released.
If a result is unusual, unexpected, or requires confirmation, the laboratory may carry out additional checks to ensure the reported result is reliable.
This can add time, but it is an important part of maintaining laboratory quality.
Does Fasting Affect How Quickly You Get Blood Test Results?
Fasting itself does not necessarily make laboratory analysis slower.
However, fasting may be required for certain tests to improve the accuracy or interpretation of the result. Your healthcare provider or laboratory should tell you whether fasting is necessary before your particular test.
If you are unsure how to prepare, you can learn more about preparing for blood tests before your appointment.
It is also important not to assume that every blood test requires fasting.
What Happens After Your Blood Is Collected?
After your sample is collected, it is usually labelled and registered before being processed.
The laboratory then performs the requested analysis using the appropriate testing method.
Once the analysis is complete, the results may go through quality checks and review before the final report is released.
The report can then be provided to you through the laboratory's available reporting system or returned to the healthcare professional who requested the test.
So, when a laboratory says a result will be available within a particular timeframe, that timeframe may include several stages between sample collection and final report release.
What Should You Do If Your Results Are Taking Too Long?
If your results have not arrived within the timeframe given by the laboratory, you can contact the laboratory and ask about the status of your test.
Have your sample or request information available so the laboratory can locate your record quickly.
You can ask:
- Has my sample been processed?
- Is the test still being analysed?
- Does the laboratory need another sample?
- Was the sample sent to another facility?
- When should I expect the final report?
If the test was requested because of a medical concern, also follow any instructions given by your healthcare provider rather than waiting indefinitely for an online result.
Can You Get Blood Test Results on the Same Day?
Yes, some blood test results can be available on the same day, particularly when the laboratory performs the test in-house and the analysis is relatively routine.
However, same-day results should not be assumed for every test.
The expected turnaround time depends on the specific investigation, laboratory facilities, sample requirements, workload, and whether additional verification is necessary.
How to Get Your Blood Test Results Faster
You cannot always control how quickly a laboratory processes a test, but you can reduce avoidable delays by preparing correctly.
Before your appointment:
- Confirm whether fasting is required.
- Follow the laboratory's sample collection instructions.
- Provide accurate patient information.
- Tell the healthcare professional about relevant medications or supplements when appropriate.
- Arrive within the recommended collection period.
- Ask for the expected turnaround time before leaving the laboratory.
Most importantly, use a laboratory that has the appropriate equipment and expertise for the test you need.
If you are looking for laboratory testing for health screening or specific medical investigations, you can explore AnalysisAfrica's medical testing services to see the types of tests available.
Blood Test Turnaround Time: What to Remember
There is no universal waiting time for blood test results. A routine test may be completed relatively quickly, while specialised investigations can take several days or longer.
Delays can occur because of the type of test, sample preparation, sample quality, laboratory workload, equipment issues, external testing, or additional result verification.
If your result is taking longer than the timeframe you were given, contacting the laboratory is the simplest way to find out what is happening with your sample.
For more practical information about laboratory testing, preparation, and understanding test results, you can also read more guides on the AnalysisAfrica blog.
