Need some advice on "MySQL or NoSQL?"

[Mel Khohniat]

Hi everyone,

My actual research field ist information extraction and I'm working on 
a let carefully say diagnosis tool for medical users. I extract 
entities like symptome, disease etc. from medical journals and want to 
put these entities in a database and implement my information system 
based on it later. I'm not quite sure which DB is the most compatible 
one for me a relational DB or a nonrelational one. Considering der following: I have a symptom 'Sharp headache' a 
matching disease for this could be 'migraine' or 'brain tumor' etc. 
In SQL I would have four tables for this scenario, two for symptoms 
and diseases and two other tables for symptoms and diseases IDs where I define the sate or level of them like 'sharp headache' or 'brain 
tumor in final stage' . 'match' stand for the entities-related 
references represented in documets :
(symptom, stage, symptom-ID)
(disease,stage, disease-ID)
(symptom-ID,disease-ID, match)
In other words I'll have many tables and lots of joins and more important the process of linking the entities-related references to
my joins will more or less be carried out outside a relational DB.
Now, is it actually possible to somehow tag a disease document with a symptom in MySQL like you do in NoSQL?

Beside linking the documents based on their entities I also want to allow the user to search (read) the text as well, if desired. Let say a user has a symptom 'diarrhea' so the system looks for documents with entities like 'EHEC' :) at this point I want to let the user (himselft) to also read in this document and findout that 'eating soybean sprouts' can be a possible cause for it. In other words, does MySQL provide full text search capabilities?

Can anyone give me a piece of advice whether to stay with SQL or use a NoSQL DB?

Thanks a lot in advance 

Mel