In physicist Claudius Galen's day - around 130AD - illness was thought to be the excess of one of the four humours (yellow bile, black bile, phlegm and blood), which were treatable by bloodletting and purges.
While medicine has come a long way since then, some common myths still abound. Where medical science has faltered or been less than decisive, we have stepped in to fill in the gaps of our knowledge as we seek ways of making sense of our bodies' mysterious workings.
Drink plenty of water, avoid carbohydrates to lose weight and detoxify regularly are just some of the 21st-century health mantras that are often unquestioningly accepted.
Here, telegraph.co.uk, addresses some of the most commonly held health axioms in a bid to sort the fact from the fiction.
Health mantra: We must drink eight glasses of water a day
Reality: This is one of the most popular and pervasive myths, and according to Telegraph columnist Dr James Le Fanu, it is also entirely untrue.
"The myth comes from a holistic notion that you need that amount of water per day to flush all of the toxins out of the body," said Dr Le Fanu.
In fact we need only need 750ml to one litre of water, per day. "Quite simply, if we exceed that amount, we will simply excrete it."
To find out why it's apparently a-ok to drink on certain antibiotics, how shaving has no impact on the coarseness of hair, and what really causes cancer, read the rest.