It is a headache caused by a decrease in cerebrospinal fluid (CSF) pressure, usually due to a leak of CSF through a defect in the dura mater. The most common cause is a lumbar puncture, but leakage can occur spontaneously. The main symptom is headache, which increases when standing or sitting and decreases when lying down. It may be accompanied by neck pain, nausea, tinnitus or visual disturbances. Milder cases are treated conservatively – lying down, adequate fluid intake, painkillers, caffeine. In the absence of improvement, an epidural blood patch (EBP), an interventional technique in which the patient’s blood is injected into the epidural space to eliminate the leak.