There are about three main areas for drawing blood: the median cubital, cephalic, and basilic veins. The forearm and at the back of the hand are also other possible areas for drawing a sample.
The best vein for drawing blood is the median cubital vein. It is the best because its larger and rolls or moves less than other veins. The least best is the basilic vein. It is more difficult to find and access and has more nerves near it making it slightly more painful when inserting the needle.
Most of the samples you are going to draw will be from that vein in the center of the arm. It is usually there for the picking.
Why is the Median Cubital Vein the First Choice
The median cubital vein connects the cephalic vein with the basilic vein. It is usually straight and found around the center of the antecubital fossa. On many persons’ arm it will be slightly rising above the skin surface. On others it will be just below the surface. And, on some others it will be deeper in their arm.
Most times it will be big and plump but the size will vary depending on each individual. Also, It will be more easily felt in some individuals depending on the amount of muscle and fat tissue the person have.
The median cubital vein is the first choice for venipuncture. It is usually easy to access and is more stable. Knowing the anatomy of the arm will help you in locating and identifying the median cubital vein.
How to find the vein? Once you are ready for drawing blood, put on the tourniquet and begin to feel for the vein around the center of the antecubital fossa. If the vein is close to the surface, you should find it easily. If it is deeper in the arm it may take a little longer to feel and find it.
Once you have found it and are confident proceed with the next steps.
Why is the Basilic Vein the Last Choice
The basilic vein basically runs from the palm of the hand and up your arm on the side of the ulna. Among the 3 main veins, it is probably the one closest to the elbow.
The basilic vein is the last choice for venipuncture. It is closer to the brachial artery and median nerve making it more likely that a puncture could lead to an injury of one of those structures. Because of the nerves surrounding the area drawing blood may be more painful.
Also, it is sometimes more difficult to find and less stable than the other main veins as it rolls or moves when inserting the needle.
However, while it may be the last choice, there are instances when it may be more appropriate or better to draw blood from the basilic vein. In such cases, the phlebotomist can’t locate the median cubital or cephalic vein but the basilic vein is easier to find.
How to find the vein? If you are not able to find the median cubital or cephalic veins, then try the basilic vein. Put on the tourniquet and feel for the vein. Once you have found it, take care in anchoring the vein to prevent rolling when you insert the needle to draw blood.
The Cephalic Vein
The cephalic vein, which runs up the thump side of your inner arm is the second choice of the 3. It is usually easy to find as its near the surface of the skin and is usually larger than the basilic vein.
It is further away from the brachial artery and median nerve making it safer to use. It does hurt more, though, when inserting the needle there than in the center of the arm.
It has the tendency to roll sometimes so care must be taken to anchor it when inserting the needle. Most of the samples you draw will either be drawn from the cephalic or median cubital vein.
How to find the vein? To find it, assess the site next to the median cubital area on the thump side of your arm. Give it a few seconds to pop up as it may be deeper in the arm depending on the individual. Once found, be sure to anchor it when inserting the needle.
Why are Veins in Antecubital Fossa Used for Venipuncture?
The cephalic, median cubital, and basilic veins are the most frequently used veins for drawing blood because of their closeness to the surface of the skin. That makes them more visible and easier to locate and feel for venipuncture.
They are also a bit larger and have a thicker lumen resulting in a faster blood flow. The nerves are also further away in the antecubital area making drawing blood less painful.
Other veins at the back of the hands or in the forearm can be used but the antecubital area is the first choice.
Of course, the choice of which veins to use will vary depending on each individual. Some persons have good veins and others have veins that are difficult to find. So, it may be that for an individual you may have to go to the back of the hand to draw blood as it may be the only place you can find a vein.
What are the Five Sites for Venipuncture?
The five places for drawing blood include:
- Antecubital fossa. That is the first choice for drawing a blood sample. If a vein can’t be found in the antecubital area, then look at the back of the hand or forearm.
- Back of the hand. Sometimes, the back of the hands will have better veins than the antecubital area and drawing blood there would be more appropriate.
- Forearm. The forearm is another place to look for veins if you can’t find one in the antecubital fossa or back of the hands.
- Wrist. The wrist is a last resort for drawing blood. Sometimes, nurses or a doctor may go there but those are rare instances.
- Foot. The foot is also a last resort. Nurses and doctors will sometimes draw blood from the foot when there are no other options.
There are also a few more areas like the femoral vein for example where a doctor may draw blood when peripheral vein access is not possible.
How to Pick a Vein
Picking a vein is not difficult. Sometimes, it will be so easy and at other times it will be difficult. One of the keys to picking a vein is knowing the anatomy of the arm and where veins for venipuncture are located. If you have that picture then the next steps become easier.
The first place to look at is the antecubital fossa as it is the first choice for drawing blood. Knowing the location of each vein, go to the respective area to find it. If the vein is visible then you can already make a choice. If it is not visible, then you will have to palpate and try to feel for it.
If you can’t find a vein in the antecubital area then go to the back of the hand or forearm and follow the same steps.
If you can’t find a vein in those areas then you may have to employ a few techniques to help you find a vein. I wrote an entire article about best tips for difficult veins. Go check it out here.
Why can’t they Find my Veins when Taking Blood?
One reason is because you may have hard-to-find veins or you may be dehydrated. There are several causes for hard-to-find veins. These include:
- Small/thin veins. Small veins can be hard to locate and feel.
- Obese patients. A lot of fat tissue in the arm area or at the back of the hand makes it difficult to feel a vein.
- Deep veins. Veins deeper in the arm can be hard to feel and locate.
- Muscular patients. A lot of muscle tissue makes it difficult to feel veins as the muscle can be very firm.
- Fear of needles. A fear of needles can cause a person to feel anxious, have panic attacks or even faint. When that happens it can be difficult to locate veins.
- Dehydration. Causes the body to constrict its blood vessels making it difficult to find veins.
What does Hard Stick Mean?
Hard stick is when it is difficult to draw blood from a person or vein. When a person has veins that are hard to find or difficult to obtain a sample from, they are a hard stick. Here are some causes for a hard stick:
- Fragile/collapsed veins. Vein collapses when blood is being drawn from the vein.
- Rolling veins. Vein rolls when inserting the needle.
- Individuals taking chemotherapy. Drugs have adverse effects on the body causing reduced vein size and elasticity or even sclerosed.
- Scarred areas. Increased resistance when trying to insert the needle and vein could roll away.
- Burnt areas. Resistance when inserting the needle.
Areas to Avoid for Venipuncture
Here are some sites to avoid when drawing blood from an individual:
- Arm on side of mastectomy
- Edematous areas
- Hematomas
- Arms in which blood is being transfused
- Scarred areas
- Arms with fistulas or vascular grafts
- Sites above an intravenous cannular
- Burnt areas
All of us prefer drawing blood from good and easy to find veins. However, we know that is not always the option we are presented with. Good luck!