Why do you feel faint after needles?

Feeling faint after receiving a needle, such as during a vaccination or blood draw, can be attributed to a combination of factors. These may include vasovagal reflex, where the body reacts to stress or pain by lowering heart rate and blood pressure, leading to faintness. Anxiety or fear of needles can also trigger this response, as well as dehydration or low blood sugar. It's important to stay calm and inform healthcare providers if you have a history of feeling faint during such procedures.