An organic headache is the result of an abnormality in the brain or skull. It can be caused by a benign or malignant brain tumour, a brain aneurysm, haematoma, meningitis, brain abscess, cerebral haemorrhage or encephalitis.
Very few headaches (less than 5 percent) are caused by tumours. A tumour will cause a headache if it intrudes on an artery or increases the pressure inside the brain or skull. These headaches generally start suddenly and intensely. It may get progressively worse and can be aggravated by coughing, changing positions or physical activity. Often they cause waking from a deep sleep. Associated symptoms may include: sudden lack of balance or falling, confusion, inappropriate behaviour, seizures, or difficulty seeing or speaking.