In the earliest medical texts the spleen often features, with many important functions ascribed to it. In Chinese medicine it is literally central, known as pi and one of the major solid (yin) organs. It is the internal manifestation of the Earth element (tu), responsible for assimilation, processing and nourishment (this overlaps a lot with what we consider is the liver’s role), associated with late summer, healthy food, motherhood, and is also the emotional seat of empathy.
In Graeco-Roman or Galenic medicine (the basis of western traditions and the forerunner to Islamic medicine) the spleen also holds the Earth element in the body, it is associated with autumn, cold and dry weather, and is the receptacle of black bile from the liver. In Greek black bile translates as melan cholia and so the spleen is also the seat of depression.
And yet in modern medicine the spleen has a supportive role, in processing red and white blood cells. It sits quietly in the back of the upper left abdomen, dark red in colour, about the size of a cricket ball or baseball. If it is damaged it may be removed to avoid internal haemorrhaging, and people can survive well without it. How could our forebears have such a different view of it?
One clue lies in the early years of medical training. We learnt that we could not palpate the healthy spleen (ie. locate it by pressing with our hands over the abdomen). With a firm shove under the left side we might sometimes feel it bumping against the other hand – but we were not sure if we were imagining it. However we also learnt that in liver disease (hepatitis or cirrhosis) the spleen does become palpable. Why? The reason is that the spleen, like the digestive tract, is on the portal circulation: its blood drains into the liver for first-pass processing. If the liver is damaged the portal circulation backs up. In extreme cases there is a particular type of oedema (ascites) where the abdomen bloats with fluid. However an earlier sign often is an enlarged spleen that is palpable from the front.
Early physicians must have noticed this: the spleen ‘emerging’, and then associated that with what we now call the liver. These were canny observations, but without modern investigative techniques led to different interpretations.