12/05/2026
What Happens to Your Lungs During Ascent? | IANTD
You’ve probably heard this during your Open Water course:
⚠️ “Never hold your breath while diving.”
But do you know the REAL reason why? 👇
🌊 What happens during ascent?
As you ascend:
• Water pressure decreases
• And the air inside your lungs EXPANDS
It’s basic physics.
The lower the pressure, the greater the volume of air.
🫁 So what’s the danger?
If you hold your breath while ascending, that expanding air becomes trapped inside your lungs.
And that can cause:
⚠️ Lung injuries
⚠️ Ruptured alveoli
⚠️ Arterial gas embolism (serious and potentially fatal)
Even in shallow water.
🧠 Think of it like this:
A balloon rising toward the surface 🎈
The air inside expands.
Your lungs work the same way.
✅ How do you avoid it?
Simple:
• Breathe normally
• Never hold your breath
• Ascend slowly and in control
🎯 Simple takeaway:
During ascent, the air in your lungs EXPANDS.
That’s why in diving:
👉 Never hold your breath.
Continuous breathing.
Controlled ascent.
Safe diving.
