Sorry to hear about your health. Medical expenses are Non-refundable tax credit. Therefore, they only reduce your tax payable. The credit allowed depends on your net and taxable income. For example: if your taxable income is lower than $14,000. and you have no tax payable, the medical credit will not be applicable.   

If you are eligible to make the claim, your medical expense total must be higher than 3% of your net income to become an allowable credit.  

For more information, please see this TurboTax article. How to Deduct Your Medical Expenses? 

Also, here's the blog by CRA: Line 33099.

Thanks for considering TurboTax.