fluid
Meaning of fluid: Fluid refers to any substance, liquid or gas, that flows and conforms to the shape of its container.
Definition of fluid
Fluid is a general term for a substance that flows and takes the shape of whatever container holds it, a category that includes both liquids and gases. In the body, the word most often refers to liquids, such as blood, lymph, cerebrospinal fluid, and the fluid found within and between cells, though clinicians also use it to describe intravenous solutions given to a patient.
Body fluids are generally divided into fluid held within cells and fluid outside them, and the balance between these compartments, along with the total amount of fluid in the body, is regulated by the kidneys, hormones, and a person's intake of water and salt. Maintaining this balance is essential for normal cell function, blood pressure, and organ performance.
When fluid balance is disrupted, whether through excessive loss, inadequate intake, or a medical condition affecting regulation, the result can range from mild dehydration to fluid overload affecting the lungs or other organs.
Used in a sentence
Intravenous fluid was administered to correct the patient's dehydration.
Good to know
The word fluid is used clinically both for the body's own internal fluids and for intravenous solutions administered as treatment, and the intended meaning is usually clear only from context.
Word origin
Where “fluid” comes from
Formed from Latin fluidus, from fluere, meaning to flow.