Which Machine Learning or NLP Model for text input

I am a newbie to Data Science and I would appreciate some advice for heading in the right direction. I working with a data set of medical terms. The data set has 4 fields of text. Each field is a phrase of words. These free-form phrases have been input by medical professionals. The goal is to map each of these 4 fields to text fields with standard medical terminology. What might be the best way to model this? NLP? Word2Vec? others?

Thanks.