Your diaphragm is a muscle that sits at the bottom of your lungs to help you breathe deeply. During normal inhalation, your diaphragm tightens and moves downward. During normal exhalation, the diaphragm relaxes and moves upward in the chest cavity. 

Diaphragmatic breathing—also known as "belly breathing"—is a technique that improves the amount of oxygen that enters your blood from your lungs with each breath. Diaphragmatic breathing reduces your body's stress response, making you feel more relaxed.

This article discusses what diaphragmatic breathing is, how to perform it, and tips for getting started.

What Is Diaphragmatic Breathing?

Diaphragmatic breathing teaches you to breathe deeper into your belly, rather than taking shallow breaths in your chest. When you breathe in, your lungs need to expand to fully fill with air to bring oxygen into your body. As you breathe out, your body gets rid of a waste product called carbon dioxide.

Shallow breathing in your chest limits the amount that your lungs can stretch when you breathe in and prevents you from breathing out all of the stale air in your lungs. This type of breathing often occurs when you are under stress.

Your body's sympathetic nervous system triggers a "fight or flight" response when you are stressed to help you react to a perceived danger. Diaphragmatic breathing activates a different part of your nervous system, called the parasympathetic nervous system, which has the opposite effect.

How to Perform Diaphragmatic Breathing

Proper diaphragmatic breathing can take some time to learn. In the beginning, practice diaphragmatic breathing laying down. Once you've mastered the technique, you can do it just about anywhere.

1. Lay on your back on a firm, comfortable surface.
2. Bend your knees and put your feet flat on the surface.
3. Place one hand on your chest and the other on your belly, below your ribs.
4. Breathe in slowly through your nose. Picture your belly filling with air, from the bottom up. Watch your hands as you breathe—only the hand on your belly should rise.
5. Purse your lips as if you are blowing out candles and slowly breathe out. Your belly should deflate.

Diaphragmatic Breathing Exercises

Once you've mastered basic diaphragmatic breathing, try these variations.

4-7-8 Breathing (Numbered Breathing)

1. Sit up straight in a comfortable position.
2. Breathe in slowly through your nose as you count to four.
3. Hold your breath as you count to seven.
4. Breathe out through your mouth as you slowly count to eight.

Box Breathing

1. Sit up straight and close your eyes.
2. Breathe in as you slowly count to four.
3. Hold your breath for another slow count to four.
4. Breathe out slowly as you count to four.
5. Pause for another count of four before taking another breath in.
6. Repeat three to four times.

Progressive Muscle Relaxation

1. Find a quiet environment.
2. Lie down on a firm but comfortable surface and close your eyes.
3. Tense the muscles in your hands as you slowly take a deep breath in.
4. Relax your hands as you breathe out.
5. Tighten the muscles in your forearms and wrists with the next breath.
6. Relax these muscles as you breathe out.
7. Continue this process, working your way up to your arms, neck, and face, then work your way down your legs.

Progressive muscle relaxation can also be performed using an audio recording to walk you through the steps.

Tips for Getting Started

While you're learning how to do a diaphragmatic breathing exercise, set aside five to 10 minutes several times per day for practice. Once you've got the technique down, find ways to incorporate it into your daily schedule.

Be patient—diaphragmatic breathing takes practice and in the beginning it's even more difficult to do it correctly, especially if you're already stressed.

Summary

Diaphragmatic breathing, or belly breathing, is a deep breathing technique. This type of breathing increases the amount of oxygen delivered from your lungs to your blood. Diaphragmatic breathing triggers a response in your body that can decrease stress and lower blood pressure.

A Word From Verywell

Diaphragmatic breathing is a stress management tool that can be performed virtually anywhere, once you've mastered the basic technique. In the beginning, you might need to schedule deep breathing practice sessions. However, over time, deep breathing can become second nature.