Can severe hyperventilation cause a brain aneurysm to rupture? i have a 2mm aneurysm and had a terrible panic attack tonight that caused severe hyperventilation and loss of oxygen. i am now worried about rupture? even though it is very small?

Your aneurysm is small. Those under 7mm are at lower risk for rupture. A panic attack would not increase the risk of rupture.

The critical size for rupture has been shown to be usually above 9 mm., so yours is unlikely to burst. Hyperventilation will not normally be a trigger for a brain hemorrhage. However, you need to address your emotional issues, and you might find counseling and/or biofeedback to be pathways to stability.