What is the main purpose of using an alcohol swab before a blood draw?

The primary purpose of using an alcohol swab before a blood draw is to sterilize the skin. This practice is essential in reducing the risk of infection by eliminating or significantly reducing the number of microbes present on the skin's surface. By thoroughly cleaning the area where the needle will be inserted, healthcare professionals create a safer environment for the procedure, ensuring both the patient's and the technician's safety.

While increasing blood flow, making needle insertion easier, or providing a barrier against bacteria might seem relevant in the context of drawing blood, their roles are not as critical as the need to sterilize the skin. The use of an alcohol swab effectively addresses the infection control aspect of the procedure, which is of utmost importance in any invasive technique involving skin penetration.