Non Migrainous Vascular Headaches
This headache associated with dilation of the cranial arteries and can be induced by a wide variety of diseases and conditions. The most common causes are fever, anoxia (lack of oxygen), anemia, high altitude, physical effort, hypoglycaemia (low blood sugar), foods, and chemical agents.
In addition, this headache may result from congestion and edema of the nasal membranes, often termed vasomotor rhinitis, which is assumed to be a localised vascular reaction to stress