My arm hurts after having my blood drawn

In our daily lives, we may encounter various diseases that require blood tests, or we may experience arm soreness after donating blood. The pain usually does not last too long. It is mainly caused by stimulation of the peripheral nerves. If the degree is relatively severe, local hot compresses can be used to improve it. Let’s take a detailed look at the various problems encountered during blood drawing.

1. Your misunderstanding of the needle eye

Do you think there is only one needle hole after drawing blood? In fact, there will be two needle holes when the blood collection needle is punctured. One is the skin needle hole, and the other is the blood vessel needle hole. These two needle holes are often due to differences in the operator's technique, the angle of needle insertion, the thickness of skin fat, the depth of the blood vessel from the skin, etc., which makes it that not all blood collection needles can enter the skin and blood vessels at the same time. Sometimes after entering the skin, they move a small distance parallel to the blood vessel before entering the blood vessel, which is the so-called vascular needle hole. However, your usual pressing method only presses the puncture holes on the skin and ignores the puncture holes in the blood vessels. In addition, flexing the arm cannot effectively stop bleeding and can easily lead to subcutaneous hemorrhage.

2. Why don’t you bend your arms?

Because straightening your arm can effectively reduce the internal pressure of the blood vessels when pressing after venous blood collection, it can effectively reduce the leakage of blood from the needle hole in the blood vessels and cause subcutaneous congestion (that is, the bruises you see on your hands). When you bend your elbow, it hinders the return of the elbow veins, thereby increasing the intravascular pressure of the elbow veins. Therefore, blood can easily seep out of the needle hole in the blood vessels, forming subcutaneous congestion, which is the bruise you see at the blood drawing site.

To put it simply, when a rubber hose has a small hole, if you bend the hole front and back to form an angle, even if you block the hole, water will leak out of the hole due to the squeezing force from the front and back. However, when you lay the rubber hose flat and block the water outlet, it will continue to flow in the original direction and will not easily leak out from the water outlet.

3. Correct pressing method

After the blood is drawn, at the moment the needle tip is pulled out of your skin, immediately press a sterile cotton swab parallel to the blood vessel where the puncture point is located for 5 minutes. The top of the cotton swab should be 50px beyond the proximal end of the skin needle hole (close to the heart). In this way, both the skin needle hole and the blood vessel needle hole are pressed at the same time.

Also, please note that your elbow should be straight when pressing! Due to blood vessel reasons, some people also need to have blood drawn at the wrist or back of the hand. At this time, in order to prevent the pressure point from slipping or insufficient pressure, press the top of the cotton swab with the thumb of one hand while the other four fingers press on the other side to form two upper and lower fulcrums. This will ensure the hemostasis effect!