How long does an epidural blood patch last?

Great Relief: Epidural blood patch (ebp) as a treatment for post-dural puncture headache in obstetrical anesthesia has a reported success rates in the 70% - 95% range, producing either permanent or partial relief. Rarely, a 2nd ebp will be required and it has an even higher success rate. Once a clot forms in the epidural space, headaches very rarely return.

Usually long enough: A successful epidural blood patch will usually last longer than needed for the puncture in the dura (the leak of spinal fluid from the puncture causes the headache) to heal itself. It is highly unlikely your headache will return.