A method for detecting occult hemorrhages is provided. The method comprises: obtaining, by a medical system comprising a blood monitoring system, a first hematocrit concentration prior to infusing a saline solution into a bloodstream of the patient; infusing, by the medical system, the saline solution into the bloodstream of the patient; obtaining, by the medical system, a second hematocrit concentration after infusing the saline solution into the bloodstream; determining, by the medical system, a first absolute blood volume based on the first hematocrit concentration and the second hematocrit concentration; generating, by the medical system, a notification indicating a potential occult hemorrhage based on the first absolute blood volume and a pre-defined absolute blood volume threshold; and providing, by the medical system, the notification indicating the potential occult hemorrhage.