What should you do if someone complains of dizziness after getting up suddenly?

When someone complains of dizziness after standing up suddenly, the most appropriate action is to lie them flat on the floor. This position helps to restore blood flow to the brain and can prevent falls or fainting, which is a common risk associated with sudden dizziness. Being flat reduces the chance that the individual will experience further imbalance or loss of consciousness.

In contrast, having them walk around could exacerbate their dizziness and increase the risk of falling. Giving them a glass of water might be beneficial if dehydration is the issue, but it doesn't address the immediate safety concern. Helping them sit up slowly is indeed a good practice for preventing dizziness in the future, but when someone is already feeling dizzy, lying them down is more effective for their immediate safety and comfort.