Last Updated: October 23, 2023

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The diaphragm plays an essential role in the body, controlling breathing, maintaining posture, and assisting digestion. A healthy diaphragm is crucial to the body’s overall health and functioning. One can train and strengthen the diaphragm with breathing exercises.

What is the Diaphragm?

The thoracic diaphragm, also called the diaphragm, is a large, dome-shaped muscle in the abdomen. It is the primary muscle of respiration - breathing - and is responsible for inhaling and exhaling.

Functions of the Diaphragm

Inspiration: The Diaphragm Contracts

Inspiration is the inward part of breathing, drawing air through the nose and mouth into the lungs.

As the diaphragm contracts, the rib cage lifts and pulls the lungs down, increasing their volume and creating negative pressure. This lift pulls air in so gas exchange can occur within the air sacs in the lungs.

Expiration: The Diaphragm Relaxes

Once the lungs have exchanged oxygen for carbon dioxide, that spent air must be exhaled by expiration.

The diaphragm relaxes, pushing upward, drawing the rib cage down and reducing the volume of the lungs, pushing CO2-dense air out through the nose and mouth.

Coordination with Other Respiratory Muscles

While the diaphragm is the primary muscle involved in respiration, it is not the only one. The diaphragm coordinates with several other muscles voluntarily and automatically to perform breathing functions.

These are known as the accessory respiratory muscles, and they increase the volume of oxygen processed by the lungs. The pectoralis major, serratus anterior, and trapezius aid in expanding the chest cavity to force more air in.

Importance of the Diaphragm

Daily Life Body Function

The body will not function without breathing. The diaphragm is the primary muscle involved in the breathing process for both inhaling and exhaling.

Breathing is primarily controlled subconsciously by the autonomic nervous system—the respiratory rate controlled in the brain stem. The brain stem signals the diaphragm to relax and contract as oxygen needs dictate.

One can also control breathing rates manually. Lying lazily in bed has lower oxygen demands than running to catch the bus, but that doesn’t prevent one from voluntarily taking a deep breath.

The diaphragm is one of the body’s most active large muscles, regularly expanding and contracting throughout the lifespan.

Aerobic Exercise

During aerobic exercise, the body’s oxygen demands go up. That means more air needs to come in, so the diaphragm needs to work harder.

Regular aerobic exercise can strengthen the diaphragm, meaning more efficient breathing and a longer time to fatigue during vigorous aerobic exercise.

Anaerobic Exercise

The diaphragm is vital in anaerobic exercise, even when the body doesn’t need extra air.

The diaphragm and abdominal wall muscles are largely responsible for “bracing” or building the intra-abdominal pressure needed to keep the core stiff and stable when needed, like during a heavy squat or cheerleading throw.

Location and Anatomy

The diaphragm is located near the middle of the torso, separating the thoracic and abdominal cavities.

It forms the floor of the thoracic cavity and the roof of the abdominal cavity, attaching to the lower borders of the ribcage and sternum (breast bone) in the front, the spine in the back, and the costal cartilages (cartilages that connect the ribs) on the sides.

The diaphragm forms the border of the inferior thoracic aperture, closing off the opening between the abdominal and thoracic cavity.

The diaphragm’s muscle fibers run inwards, and its attachments converge toward the central tendon, which runs across and within the muscle but does not connect it to any bones. The fibrous pericardium surrounding the heart fuses with the central tendon just above the diaphragm.

Related Organs

The heart sits on the left half of the body within the thoracic cavity, just above the diaphragm. The stomach, liver, kidneys, and other vital abdominal organs sit below the inferior surface of the diaphragm in the abdominal cavity.

The diaphragm forms a border between the heart, lungs, and abdominal organs.

Related Musculature

The diaphragm may be the most essential muscle in breathing, but like most muscles, it doesn’t work alone.

Straightening the back, lifting the chin, and fully expanding the lungs for a deep breath wouldn’t be possible without the work of the intercostal muscles of the ribs, the upper back and neck muscles, the chest, the obliques, and the abdominals.

Skeletal Anatomy

On the front of the body, the diaphragm originates on a small cartilaginous extension of the breastbone called the xiphoid process.

Around the sides, its peripheral attachments meet inside the costal cartilages at the lower borders of the lower ribs, ribs 6-12. On the back of the body, the diaphragm attaches to the arcuate ligaments of lumbar vertebrae L1-L3 in the spine.

Phrenic Nerve and Arteries

Due to its vital job in breathing, the diaphragm has its own specific blood and nervous supply system.

The phrenic nerve originates in the cervical spinal cord (C3-C5) and travels down the neck and chest to the diaphragm. The phrenic nerve splits and gives the diaphragm signals to contract and relax under automatic or manual control.

Blood is supplied primarily by the phrenic arteries, starting with the internal thoracic arteries, then branching to the musculophrenic and inferior phrenic arteries.

Veins throughout the muscle collect blood in the inferior vena cava and return it to the heart through an opening in the diaphragm, the caval opening, to repeat the oxygenation cycle.

From Chest Cavity to Abdominal Cavity: Just Passing Through

The diaphragm separates the chest and abdominal cavities, but some things, like food and blood, still need to pass through. For that reason, several passages through the diaphragm exist. Each of these passages is known as a hiatus and serves a distinct purpose.

  • Esophageal hiatus: a gap through which the esophagus passes for food to travel from the mouth to the stomach.
  • Aortic hiatus: an opening for blood transport through the aorta to the circulatory system. The aorta is surrounded by the median arcuate ligament, which wraps around it and connects to the spine at the first or second lumbar vertebra.
  • Caval opening: each of two small gaps that allow the inferior vena cava on the right and the smaller hemiazygos vein on the left to return deoxygenated blood to the heart.
  • Thoracic duct: a vital port for collecting and transporting lymphatic fluid through the body, with lymphatic vessels draining into the duct. The diaphragm works as a pump to circulate this lymphatic fluid back through the lymphatic system.

Diaphragm Health

Importance of a Healthy Diaphragm

A healthy diaphragm is crucial for breathing and, therefore, critical for every other aspect of life.

Because of its role in breathing, issues or conditions with the diaphragm can cause severe symptoms and complications, including chest pain, difficulty breathing, uncontrollable hiccups, a distended stomach (stomach bulges), acid reflux, and more.

Keeping the diaphragm healthy with regular exercise and purposeful activity decreases the likelihood of a medical emergency. Beyond that, a healthy diaphragm supports healthy living.

Common Disorders and Conditions

There are some common disorders and conditions of the diaphragm with varying symptoms and severities. Diaphragm health should be a priority for everyone.

If one has concerns regarding their diaphragm, it is crucial to discuss them with a doctor immediately. Some common diaphragm conditions include:

  • Congenital diaphragmatic hernia: a form of hernia in the diaphragm present from birth. This form of hernia is a hole in the diaphragm through which internal organs can move. This condition is often diagnosed by ultrasound during pregnancy and requires surgical repair after birth.
  • Acquired diaphragmatic hernia: unlike congenital hernias, an acquired diaphragmatic hernia occurs when the diaphragm weakens or tears after birth, allowing passage of materials or organs into the thoracic cavity. Depending on the severity, an acquired hernia may require surgical repair, with immediate surgery being the best option to prevent breathing or organ function complications.
  • Hiatal hernia: This specific hernia involves the movement of the stomach through the inferior surface of the diaphragm. In a hiatal hernia, the stomach pushes upwards and protrudes into the chest cavity. A hiatal hernia is rarely life-threatening but can cause stomach or chest pain, discomfort, and acid reflux and may lead to esophagitis or gastroesophageal reflux disease (GERD).
  • Neuromuscular disorders: some neuromuscular disorders can affect diaphragm function. These disorders can impede the diaphragm’s neuromuscular control system and prevent it from functioning, causing shallow breaths, difficulty breathing, or complete cessation of respiration. Neuromuscular disorders can result from disease, infection, or genetics and usually require serious medical care.
  • Diaphragmatic paralysis: diaphragmatic paralysis refers to any conditions where the diaphragm’s movement is partially or entirely lost. Paralysis is generally caused by phrenic nerve damage when the phrenic nerves are severed or exposed to trauma.

Training and Strengthening the Diaphragm

The diaphragm can be strengthened and trained like all muscles with mindful exercise. Because its primary function is breathing, training for the diaphragm usually involves specific breath work.

  • Diaphragmatic breathing: diaphragmatic breathing, also known as belly breathing or deep breathing, involves taking very deep, slow breaths and forcing the lungs to expand as much as possible. In addition to stretching and strengthening the diaphragm, belly breathing can increase lung capacity and efficiency, promote relaxation, and reduce stress.
  • Wim Hof breathing: The Wim Hof method of breathing is named after the man who popularized it, Wim Hof, or “The Iceman.” The process involves deep, rhythmic breathing alternated with long breath holds. These breathing exercises are often combined with cold immersion - a form of cryotherapy - to magnify their effects. This diaphragm work improves blood oxygen concentration, promotes circulation, improves energy, and reduces stress.

Frequently Asked Questions

What Does the Diaphragm Do?

The diaphragm produces movement responsible for breathing but also assists in maintaining good posture, digestion, core stability, and more. It is crucial for many aspects of daily life.

Can the Diaphragm be Trained?

Yes! The diaphragm can be trained through breathing exercises. A strong diaphragm is essential for respiratory health, as well as for athletic performance. Singers and wind instrument players stand to benefit from diaphragm training, too.

What Can Cause Diaphragm Problems?

Most issues related to the diaphragm are caused or exacerbated by lifestyle factors associated with poor health. Smoking, obesity, heavy alcohol use, and a sedentary lifestyle are the most common conditions related to diaphragm problems.


Phrenic Nerve Injury - StatPearls - NCBI Bookshelf

Inferior thoracic aperture | Radiology Reference Article | Radiopaedia.org

Diaphragm: Hiatal Hernia, Diaphragmatic Breathing, What Is the Diaphragm

Diaphragm: Function, Anatomy, and Abnormalities

Wim Hof Breathing: Method, Benefits, and More

Anatomy of the Normal Diaphragm - Thoracic Surgery Clinics


The contents of this article are provided for informational purposes only and are not intended to substitute for professional medical advice, diagnosis, or treatment. It is always recommended to consult with a qualified healthcare provider before making any health-related changes or if you have any questions or concerns about your health. Anahana is not liable for any errors, omissions, or consequences that may occur from the use of the information provided