Which are the causes of trigeminal neuralgy and/or of cluster headache? can both be caused by stress?

Probably vascular: Definitive evidence about the cause of either condition isn't available. But it is suspected that trigeminal neuralgia is caused by enlargement of a blood vessel that presses on the trigeminal nerve, causing symptoms. Cluster headaches may be caused by the hypothalamus (part of the brain) somehow causing increased blood flow to the area of pain - the eye and temple region. Neither caused by stress.

Different: Trigeminal neuralgia and cluster headaches are very different in their causes and treatments. Stress can amplify any pain condition, and re-occurrences of trigeminal neuralgia are often linked to stressful life events.