How long should I meditate when I'm having an anxiety attack?

Short. 2 to 5 minutes maximum during acute anxiety. Your nervous system is in fight-or-flight mode — asking it to sustain focused attention for 20 minutes is unrealistic and will likely increase frustration. During a panic attack, even 60 seconds of box breathing (4 counts in, 4 hold, 4 out, 4 hold) can help. Once the acute phase passes, longer sessions (10 to 15 minutes) can help process what happened and reduce residual tension. The worst thing you can do is force a long session when you’re in acute distress.