Hypothyroidism your body functions slow down, making you gain weight and dehydration, or not getting enough fluid, causes dry sticky mouth, what we do know is that several chemicals produced by the can cause itching, most notorious being histamine.
Operations Research (O.R.), or operational research in the U.K, is a discipline that deals with the application of advanced analytical methods to help make better decisions.
Operational definition. An operational definition is the application of operationalization used in defining the terms of a process (or set of validation tests) needed to determine the nature of an item or phenomenon (e.g. a variable, term, or object) and its properties such as duration, quantity, extension in space, chemical composition, etc.