Final answer:
If too much blood is taken, it can lead to hypovolemia, which has symptoms like dizziness and fainting. Healthcare professionals follow guidelines to prevent this by checking the donor's health and monitoring the donation process.
Step-by-step explanation:
If too much blood is taken, it can lead to a condition called hypovolemia, which is a drop in blood volume. Symptoms of hypovolemia include dizziness, fainting, rapid heartbeat, pale skin, and fatigue. To help prevent this, healthcare professionals follow guidelines to ensure that only a safe amount of blood is taken from a donor. This includes assessing the donor's overall health, checking their blood pressure, and monitoring for any signs of discomfort during the donation process.