Can you get a mortgage with collections?
Hereof, can I get a mortgage with paid collections?
That depends. If you can show that a debt is uncollectible due to the statute of limitations, you probably won't have to pay it. But if you do owe the money and it's collectible, you should pay it or establish a payment plan before applying for a loan.
Similarly, can I buy a house if I have collections?
Having a record of a charge-off or collection doesn't necessarily mean you won't qualify for a home loan. In some cases they may make exceptions, but much will depend on the mortgage loan program, the amount of the unpaid debt, the reason the debt wasn't paid, and the lender's individual policies.
Medical collections won't prevent a mortgage loan from going through (though it does depend a bit on how old the collections are, since they do represent a willingness and capacity to pay your bills).