What is Alzheimer’s disease and why does salt make you thirsty?

We explore some of the curious questions that science can answer

Joe was starting to regret eating all the salted peanuts (Getty)

Why does salt make you thirsty?

When salt crystals, which have a very orderly structure, get the chance to dissolve in water, they take it – because the level of disorder (or “entropy”) increases when the crystals become disordered ions in water. The drop in entropy when salt dissolves is much greater than for many other things – so salt preferentially takes water from other chemicals or states. Thus salt in your mouth or stomach sucks water from your bloodstream. This triggers sensors in the brain, which alert you that there’s less water in your blood circulation. In other words, you feel thirsty.

What is Alzheimer’s disease?