text box v. text area

Hi.  I created a client intake form for my nutrition practice.  I have asked many open ended questions in the form I have created, using text boxes.  

Does the client have any max character limits?  I am thinking I should have used text areas instead of boxes for open ended questions that will take several sentences to answer. Is that correct? If so, what would be the easiest way to change all of these on my document?

Thank you.

I believe you have already opened a thread about this concern.

Which-field-is-best-to-use-for-open-ended-questions#2

Please refer to that thread as I was able to answer it already. 

Thank you.