For each of the body fluid disturbances A–E, select the most appropriate option from the following list of abnormalities

A. Option 2 Hypo-osmolality. Excessive retention of water dilutes all the body fluids leading to hypo-osmolality. Water crosses the cell membrane until equilibrium is attained. Inappropriately high levels of antidiuretic hormone could do this.

B. Option 5 Raised haematocrit. As fluid is lost, plasma volume declines, so the red blood cells become an increasing proportion of blood volume.

C. Option 1 Hyper-osmolality. The high glucose raises the osmolality proportionately, so a rise of 25 mmol/litre in the extracellular glucose level would raise the osmolality from 285 to 310 mosmol/kg, an appreciable rise. This would draw fluid from cells, including brain cells, disturbing function.

D. Option 2 Hypo-osmolality. Drinking excessive amounts of water has the same effect as excessive retention by the kidney. However healthy people promptly excrete the excess fluid.

E. Option 2 Hypo-osmolality. Excess water is drawn into brain cells by osmosis. This also disturbs brain function.