#Spain has 17 different health insurance cards, 16 of those are, in many cases, only valid in their own comunidad autónoma. That means that, for example, my Catalan health card works fine in Catalonia but maybe it won't be accepted in Madrid, same can happen otherwise. Unless you know your Seguridad Social number, your card will, most likely, not be accepted somewhere else.  Because of that, a lot of people in Spain have both autonomous health card and the European Health Insurance Card. 

PS: The CatSalut card in this picture (which is the Catalan one) is NOT like that. It doesn't have that chip or VISA stuff!