Injected fluids is a medical term referring to the process of introducing liquids into the body through a needle or syringe. The most common example of this is an injection of medication, such as a vaccine or antibiotic. In some cases, fluids may also be injected for therapeutic purposes, such as to provide hydration or to flush out toxins. The term SERA, which is a 4-letter word, is an acronym for 'serum albumin, ' which is a type of protein found in the blood that helps to regulate fluid balance in the body.