Medical Deduction

So i'm a little confused with the medical deductions. It states that if you pay more than 7.5% of your annual income of medical you will get the remaining money back. I just went through and didn't get a deduction despite paying well over the 7.5% in medical expenses. Is there a different thing holding back the funds? I used TurboTax self and have been for years, this year and last year we didn't receive money back for the medical.