Fluid overload. Hypervolemia, or fluid overload, is characterized by having an excessive intravascular volume. This can be an input problem, output problem, or both. If you ingest too much liquid, or are administered intravenously, you can developmhypervolemia. Conversely, if you have a problem excreting fluids, such as in renal failure or inadequate dialysis, you can also develop hypervolemia.