Can we “suspect” a diagnosis “in advance”?

Could we make a diagnosis “before” the devastating consequences of a subarachnoid hemorrhage?  Can we make an early  diagnosis of cancer only using the symptoms and signs of a person? The NHS in United Kingdom has established a four weeks period of time after a suspicion of cancer for a definitive diagnosis, but how a doctor can get this “suspicion”? 

We believe that this situation that we call “prediagnosis” can be achieved through a combination of intuition, professionalism, clinical prediction rules, patient engagement, clinical experience  and a proper evaluation of the signs and symptoms of the patient. This concept overlap with others well defined such as “early diagnosis” or ” diagnostic  delay” , two definitions what are defined based on the outcome. Prediagnosis in summary try to put a name to this  period of time where we can act in a prospective way to avoid an important harm to the patient.  In a first approach we could expose the  different components  of this concept to improve the diagnostic process.