The role of epidural blood patching in the prevention or treatment of the headache that may follow dural puncture (usually lumbar puncture) is inconclusive. Dural puncture involves passing a needle into the fluid-filled space around the spinal cord and nerve roots. This procedure is used to obtain spinal fluid for laboratory tests or to give a spinal anaesthetic. However, leakage of fluid through the puncture created by the needle can cause headache. One suggestion for preventing or treating this headache is to inject some of the patient's own blood around the puncture to stop the leakage (epidural blood patch). However, this review showed that, according to current evidence, clear conclusions cannot be drawn about the advantage of preventative epidural blood patch over other treatments. The use of epidural blood patch after the onset of the headache, however, showed benefit over conservative treatment. There were too few participants in the included studies, however, to allow a reliable assessment of the potential benefits and harms of this technique.