Intravenous fluids are sterile solutions administered directly into a patient's bloodstream through a vein. They are used to maintain or restore fluid balance, deliver medications, and provide essential nutrients. Common types include saline, dextrose, and lactated Ringer's solution, each serving specific medical needs. Healthcare professionals, such as nurses and doctors, monitor patients receiving intravenous fluids to ensure proper dosage and response. This method is crucial in various settings, including hospitals and emergency care, especially for patients who are dehydrated, undergoing surgery, or unable to consume fluids orally.