Drawing blood for a blood test can be a quick procedure. In fact, the process itself can take about 5 minutes or less. However, there are many factors that can make it go on for longer.
Some of these factors can be negated if the patient is well prepared for the blood test and if the phlebotomist is very skilled.
In general, it takes about 3-5 minutes to draw blood from a person. Once the person has a good vein the process is fast. If the person is dehydrated or their vein is thin, rolling, deep or hardened, the process can take longer.
The Phlebotomy Procedure
The procedure itself which entails putting on the tourniquet, finding the vein, cleaning the site, inserting the needle, collecting the blood, etc. will take about 3-5 minutes. There are several factors, though, that can extend the time for more than 5 minutes. These factors include:
- Phlebotomist’s experience: a newbie will take longer to draw blood than someone with experience.
- Dehydration: hydration makes for good veins and good veins result in a quicker blood draw.
- Time it takes to identify a vein: good veins are quick to find. Difficult veins take more time.
- Number of sticks: two or more sticks are time consuming.
- Size of veins: small or thin veins can pose difficulty in finding and sticking them.
- Difficult patients/veins: oncology, critical care and obese patients as well as fragile and rolling veins will extend the time.
Filling of the tubes is fast and can take anywhere from 10 seconds to 3 minutes depending on the following factors:
- Vacuum inside tube: if the tube is faulty or there is no vacuum blood collection will be slow. Use another tube.
- Size of needle: gauge size restricts how much blood flows out the needle.
- Extra tubes: multiple samples means more time.
- Speed of blood flow: how fast the patient’s blood is flowing. If it’s slow, it will take more time.
How Long Does the Needle Stay In for Blood Test?
The needle stays in for about 20 seconds to a few minutes. The number of tubes to be filled determine really how long the needle stays in the vein. For 1-2 tubes the needle may stay in for more than 20 seconds. For more tubes it will stay in longer.
It can stay in longer, also, if the blood stops flowing. A collapsed vein or if the needle moves out of its position can cause that.
The technician will determine what caused blood to stop flowing and what needs to be done to correct it. That could be readjusting the needle or doing a redraw altogether.
If the draw is slow going the needle will stay in for a bit longer too.
Does it Hurt to Get Blood Taken Out?
Getting blood out of a vein does not hurt and is not painful. Once the needle is in the vein collecting blood does not hurt.
The area of insertion may feel uncomfortable while the needle is in the vein or a burning sensation may be felt if there are any bruises. Also, there can be a slight hurt or pain if the person moves their arm while the needle is in the vein.
It can be uncomfortable for awhile in the case of donating blood. Blood donation may take up to 10 minutes to complete. So, having a needle in your arm for 10 minutes can be uneasy.
Do blood draws hurt? I wrote an article in which I shared 11 reasons why blood draws may hurt. Check it out here to read it.
How Long Does it Take to Do Testing?
The time it takes to process samples and for the blood tests to be completed depend on the following factors:
- Type of tests: some tests can be ready within an hour. Some in a few hours and others may take days.
- Work flow of lab/hospital.
- Situation of patient: if it’s an emergency, testing can be speeded up.
- Number of tests to be done: several tests will take more time than one test.
- Further testing: depending on the initial result further testing may need to be done for a particular test.
- Samples may have to be sent to another lab.
- Understaffed.
- Downtime (machine/equipment malfunction).
All these factors affect lab testing times, however, in general most tests are done the same day. Actually, many tests can be done within an hour but there are processes and policies by which a lab operates that dictate how long testing really takes.
Below is a table showing some common tests and the length of time it takes to complete them. These are estimates as the time will vary depending on the equipment/machine being used.
| Test | Time to Complete |
| CBC | Within minutes |
| ESR | About an hour |
| PT/INR | 30 minutes to an hour |
| PTT | 30 minutes to an hour |
| Blood Group | About half an hour |
| D-Dimer | About half an hour |
| Troponin 1 | About half an hour |
| Lipids | About half an hour |
| BMP | About half an hour |
| CMP | About half an hour |
| Urinalysis | About half an hour |
| Cultures (urine/stool) | 1 to 5 days |
| OCP | About half an hour |
| Occult Blood | Minutes |
| PSA | About half an hour |
| Drugs Screen | Under 30 minutes |
| Sickle Screen | Under 30 minutes |
| Thyroid Function | About half an hour |
| HCG (urine) | Minutes |
| HCG (blood) | About half an hour |
| HIV | 30 minutes to an hour |
| Syphilis | 30 minutes to an hour |
| HBsAg Screen | 30 minutes to an hour |
| H Pylori Ab/Ag | About half an hour |
| NT-proBNP | About half an hour |
How Long Does it Take to Receive Blood Test Results?
Blood test results can take anywhere from several minutes to a few weeks depending on the test and laboratory.
For emergency situations, results can be ready in under an hour and be sent to the doctor’s office or the person directly.
For normal times, results can be ready in 24 hours, a few days or weeks. These times are dependent on the lab or hospital as every lab operates differently.
Results are generally sent to the doctor’s office. A person may request a copy of their results also.
Below is a table showing some common lab tests and how long it takes to receive blood test results. These are estimates as the time will vary from one lab to another.
| Test | Time it Takes to Receive Results |
| CBC | 1 to 3 days |
| ESR | 1 to 3 days |
| PT/INR | 1 to 3 days |
| PTT | 1 to 3 days |
| Blood Group | 1 to 3 days |
| D-Dimer | 1 to 3 days |
| Troponin 1 | 1 to 3 days |
| Lipids | 1 to 3 days |
| BMP | 1 to 3 days |
| CMP | 1 to 3 days |
| Urinalysis | 1 to 3 days |
| Cultures (urine/stool) | 1 to 3 days |
| OCP | 1 to 3 days |
| Occult Blood | 1 to 3 days |
| PSA | 1 to 3 days |
| Drugs Screen | 1 to 3 days |
| Sickle Screen | 1 to 3 days |
| Thyroid Function | 1 to 3 days |
| HCG (urine) | 1 to 3 days |
| HCG (blood) | 1 to 3 days |
| HIV | 1 to 3 days |
| Syphilis | 1 to 3 days |
| HBsAg Screen | 1 to 3 days |
| H Pylori Ab/Ag | 1 to 3 days |
| NT-proBNP | 1 to 3 days |
| HVS (swab) | 1 to 3 days |
