Intravenous (IV) therapy delivers liquid substances directly into a vein. IV injections are the fastest way to deliver medications and fluids throughout the body. IV injection involves introducing a small amount of drug directly into the bloodstream via a vein. It allows for fast drug action in emergencies and delivers medications that may be irritating or ineffective through other routes. Potential complications include infiltration, hematoma, air embolism, phlebitis, and allergic reactions. Nurses are responsible for verifying medications, maintaining sterile technique, and monitoring for adverse reactions.