Unfortunately, warrants never expire and will be out there against you all of your life or until you get the warrant lifted and resolve your open cases. Unfortunately also, the only way to have a warrant lifted is to go back to the court that issued it, appear before the judge and go forward with your case.
The good news -- relatively speaking since warrant situations are always bad news -- is that sometimes a lawyer can appear in your place or negotiate something before you return to court that would pave the way for your safest possible return. Otherwise, you are correct; the judge will be inclined to incarcerate you and set bail in order to ensure your return.
It's not possible for me to ascertain whether, even with a lawyer, you'll end up in jail with bail set on you or for how long. That would depend on the facts and circumstances of the original cases and whether the state can still get its evidence and witnesses together. If it can, the state is entitled to prosecute you and try to convict you, just as if you'd never left in the first place. It would also depend on why you warranted. If your life was entirely out of control back then but you took positive steps to get everything in order, that could weigh in your favor. But with four different cases, the odds that at least one judge will be angry enough to want to throw you in jail are good. So you definitely don't want to return without a lawyer.
Many lawyers have free or low-cost iniitial consultations. Find a couple who do, make some phone calls and see how much a lawyer may be able to help you. One thing is sure: it is always better to come back to court on your own than to be brought back involuntarily in cuffs.