Generally neurologist would treat headaches. Common causes for headaches would be tension headaches and migraine headaches.
Tension headaches can present with pain around the forehead or the back of the head. This is due tension in the muscles of the neck where it attaches to the skull. This can be treated by injecting cortisone into the muscles.
Migraine headaches is associated with nausea, photophobia (light sensitivity) and can affect vision.
Meningitis presents with headaches, fever, neck stiffness and a depressed level of consciousness.
Brain tumours typically would cause early morning headaches and nausea and vomiting.