Hyperventilation or overbreathing is the state of breathing faster or deeper than normal, Stress or anxiety commonly are causes of hyperventilation; this is known as hyperventilation syndrome. Hyperventilation can also be brought about voluntarily, by taking many deep breaths in rapid succession.

This is when he was in the Land Of Iron.

What was the main thing that caused Naruto to do such a thing to himself? Who is to blame? And how does this affect the future?

(Also I believe Sasuke did the same thing on Itachi's death when he saw Obito.)