What should I do if my arm is swollen after blood draw?

The human body undergoes corresponding physical examinations every year, and blood tests will be included in the examinations. This is very necessary because blood tests can detect blood diseases in the body. Then there will be many problems when drawing blood, such as blood being thick and difficult to draw. So what should I do if my arm is swollen after having blood drawn?

1. Blood collection will leave two needle holes

When drawing blood from a vein, two needle holes will be left after the puncture with the blood collection needle. One is the skin needle hole that we can usually see, and the other is the blood vessel needle hole that we tend to overlook. The reason why cyanosis appears after blood is drawn is that the needle hole is not pressed properly, causing a small amount of blood to flow out and form subcutaneous hemorrhage. Due to differences in the nurse's operating techniques, the angle of needle insertion, the thickness of skin fat, the depth of blood vessels from the skin, etc., not every blood draw can enter the skin and blood vessels at the same time. Sometimes after entering the skin, the needle will move slightly upward a short distance before entering the blood vessels. Incorrect pressing method can easily result in only pressing the visible needle hole on the skin and ignoring the bleeding of the needle hole in the blood vessel.

2. Bending your arms makes you more likely to turn blue

When blood is drawn with the arm straight, pressing the needle hole and then bending the arm can easily move the blood vessel needle hole, resulting in only pressing the skin needle hole. Moreover, when the elbow is bent, the venous return of the elbow is hindered, and the intravascular pressure of the elbow vein is increased, so blood can easily seep out of the puncture holes in the blood vessels to form subcutaneous hemorrhage.

3. Repeatedly check in a short period of time

Repeated inspection in a short period of time is also an important cause of subcutaneous hematoma. Picking up a cotton swab or ball to check a stye before it has fully healed can cause it to bleed again. Not only will it cause subcutaneous bruising, but it will also delay the healing time of the stye.

Thrombocytopenia, poor coagulation function, use of anticoagulants, blood diseases, etc. can also cause bruising. For such people, bruises or spots may appear on their skin not only when blood is drawn, but also at other times if they are not careful, so they need to be taken seriously.

5. Some small details can also cause bruises

If the sleeves are too tight, blood return will be blocked and blood will accumulate in that section of the vein, prolonging the bleeding time or even causing bleeding; if you participate in strenuous activities or lift heavy objects within a short period of time after blood is drawn; or if you wash your blood directly with water, all of these may cause the bleeding time to be prolonged or cause bruising.

So, how to prevent bruising after blood drawing? Simply put, the sleeves should be of appropriate tightness, the compression area should be large, and the pressing method should be correct.

1. Press only, don’t rub

Gently rubbing the needle hole will not only fail to stop the bleeding, but will also accelerate the bleeding, which will have the opposite effect. Do not move the arm where blood is collected and do not measure blood pressure on this arm within a short period of time. This is to prevent sudden changes in blood vessel pressure that may lead to subcutaneous bleeding.

2. Keep pressing

Some people press it once and check whether there is bleeding while pressing. This not only affects the speed of stopping bleeding, but also makes it more likely to cause blood stasis. The pressing time should be long. Generally, it takes 3 to 5 minutes to stop the bleeding after blood is drawn. Special cases: For those who are older, taking anticoagulants or have platelet abnormalities, the time will be relatively longer.

How to deal with bruises?

Normally, there is no need to be too nervous. Starting the day after blood drawing, local heat compress with a hot towel can speed up blood circulation and promote the absorption of blood stasis. It usually takes 1 to 2 weeks for the blood stasis to dissipate. However, if bruises or red spots appear easily on your skin, you need to contact your doctor in time.