Did you transfer information into your return from last year? If so, you may have had unclaimed medical expenses that were added to your return for this year.
Another possibility is that you have something in Box 85 (Employee-paid premiums for private health plan) on your T4. This would be considered a medical expense.
Thank you so much. There was box 85 on my spouse's T4 so that must be it. But can tell me why that would show up on my taxes instead of his? It seems I should change this to his return but I'm not sure how to.