MySQL - Alter Table Fails As Workbench Tries To Create Existing Table
If you have a lot of records in your table, take a look at my answer to a related question here. 

With respect to MySQL Workbench, I have always found the tool to be excellent. 

Having said that, what MySQL Workbench 'may' be doing in the background is creating an empty temporary table with the extra field, copying over all the records, the deleting your old Patient table and renaming the temp table to Patient and then having problems creating the "new" Patient table. You'd have to check the source code to find out for sure what's going on - or maybe run SHOW TABLES; continuously against your system while the update was being performed. 

Where the message "The table "Analysis' is full" is coming from, I don't have a clue - does it exist in your schema? Do you have spare disk space for your MySQL datadir, or is it getting tight?

In any case, if a GUI tool fails, the first thing to do is to is to run the command from the mysql command line tool (another reason to prefer the command line), just to ensure that you're really dealing with a MySQL problem and not an issue with Workbench. Do you have the output of the error log? That might also be helpful.