Hemangiomas may remain asymptomatic or produce a variety of clinical symptoms. One of the more common is epileptic seizures due to pressure on adjacent brain tissue. Another complication may be rupture of one of the vessels causing a haemorrhagic stroke. This is further facilitated by the fact that blood flows under high pressure within these abnormal connections. The basis of diagnosis is arteriography, a type of radiological examination that aims to visualise the vessels.

Treatment usually depends on the size and location of the angioma . The most common treatments are endovascular embolisation or radiosurgery, which involves irradiating the abnormal vessels with a beam of radiation, which gradually leads to their disappearance and replacement with scar tissue.