First of all it goes on your tax return for the year you take it out. So if you withdraw it by Dec 31 it goes on 2017. After Jan 1 it goes on next year's 2018 return We file in 2019.
You will pay tax on a Traditional IRA distribution. It will add to your other income and may push you into a higher tax bracket. If you are under 59 1/2 there is also a 10% Early Withdrawal Penalty unless you have an exception. I believe medical is an exception. See IRS publication 590B for IRA Distributions
<a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-pdf/p590b.pdf">https://www.irs.gov/pub/irs-pdf/p590b.pdf</a>
Only unreimbursed medical expenses that exceed 10% of AGI are exceptions to the early distribution penalty.
All withdrawals from an IRA or taxable as ordinary income as of the date that you actually receive the money. All withdrawals made before the age of 59 1/2 are subject to an additional 10% penalty unless you qualify for a penalty exception. One of the exceptions is in medical expenses but only when they are more than 10% of your adjusted gross income.