Neurology is the scientific study of the nervous system — the brain, the spinal cord, and the nerves — and of the diseases that attack them. In hospitals it is also the name of the department that treats those problems with medicine and tests rather than with surgery. It is a formal medical-science word. Though actually, everyday speech sometimes uses it for 'anything to do with the brain,' which is a bit loose: psychology is about mind and behaviour, psychiatry is about mental illness, neuroscience is a wider lab science of the nervous system, and neurosurgery is the knife. Neurology is the medical field you meet when something is wrong with the nerves or the brain as a body organ.