Diuresis used to increase urine output and decrease extracellular fluid volume. Substances in the circulation can also increase the amount of circulating fluid by increasing the osmolarity of the blood. This has the effect of pulling water from the interstitial space, making more water available in the blood and causing the kidney to compensate by removing it as urine. In hypotension, often colloids are used intravenously to increase circulating volume in themselves, but as they exert a certain amount of osmotic pressure, water is therefore also moved, further increasing circulating volume. As blood pressure increases, the kidney removes the excess fluid
Blood is thicker than water der Glîchezære. The 13th-century Heidelberg manuscript reads in part, "ouch hoer ich sagen, das sippe blůt von wazzere niht verdirbet" (lines 265-266). In English it reads, "I also hear it said, kin-blood is not spoiled by water." which may in part refer to distance not changing familial ties or duties, due to the high seas being tamed. In 1412, the English priest John Lydgate observed in "Troy Book", "For naturally blood will be of kind / Drawn-to blood, where he may it find." By 1670, the modern version was included in John Ray's collected "Proverbs", and later appeared in Sir