In medicine the term ‘contra’ means against and the term ‘indication’ is used for a valid reason for taking a particular test medicine or procedure. So contraindication basically means against a valid reason or a reason not to take a particular test medicine or procedure. When it comes to drugs or medicines contraindication defines specific circumstances in which the drug should not be taken or can have undesirable outcome (allergies side-effects or adverse-event) if taken. For e.g. the drug asprin is contraindicated in patients with stomach ulcers because it might lead to events like internal bleeding. There are two types of