Bruising of the skin on the arm after a blood draw, which is common in clinical practice, is often due to improper pressure and does not mean that one has a blood disorder. Reasons for improper compression include the following: i. Using only one finger to press the eye of the needle, rubbing while pressing. Second, the duration of pressure is less than five minutes, the sleeve is not relaxed after the blood is drawn, and the arm is bent during the pressure. If the above deficiencies are overcome after the blood draw, skin bruising can be avoided. If the above-mentioned deficiencies are overcome and bruising still occurs, attention should be paid and further examination by a hematologist is required. If the bruising is really caused by a blood disorder, it is often multiple bruising, which means that in addition to the bruising at the site of the blood draw, there will be other areas of skin bruising. There will also be signs of bleeding from other areas, such as nosebleeds, gum bleeds, gastrointestinal bleeds, urinary tract bleeds, etc. Therefore, there is no need to worry too much about skin bruising after blood draw.