What is the thing below your chest called?: An Anatomy Guide

October 2, 2025 •

3 min read

Over 200,000 Americans undergo chest X-rays each year, which can reveal details about the structures located below the breastbone, an area often referred to simply as the “thing below your chest”. The region houses several important anatomical features, including a small, bony extension of the sternum, the primary muscle for breathing, and the uppermost part of the abdomen. Understanding these different components is key to deciphering symptoms and promoting overall health.

Quick Summary

The area below the chest can refer to the xiphoid process (a bony tip of the sternum), the diaphragm (a major breathing muscle), or the epigastric region of the abdomen. Each structure has distinct functions and potential health concerns.

Key Points

Xiphoid Process: The pointed, bony tip of the sternum.
Diaphragm: A large, dome-shaped muscle beneath the lungs essential for breathing.
Epigastric Region: The upper-central abdomen, containing organs like the stomach and liver.
Pain Causes: Pain can stem from issues with these structures, including xiphoid syndrome, diaphragm irritation, or conditions like acid reflux.
Medical Landmark: The xiphoid process is a reference point for procedures like CPR.
When to See a Doctor: Persistent or severe chest pain requires medical evaluation to rule out serious conditions.

Navigating the Anatomy Below Your Chest

When someone refers to the “thing below your chest,” they could be talking about one of several important anatomical structures. This area of the human torso, or trunk, is where the protective rib cage ends and the abdominal cavity begins. Key players in this region include a bony landmark, a vital respiratory muscle, and the top portion of the abdominal region itself.

The Xiphoid Process: A Pointed Landmark

The xiphoid process is the smallest and lowest part of the sternum (breastbone). It starts as cartilage and ossifies into bone over time. It serves as an attachment point for muscles, including the diaphragm and abdominal muscles, and is a landmark for procedures like CPR. Pain in this area, called xiphoid syndrome, can be caused by trauma or strain. Although rare, a fracture can occur.

The Diaphragm: Your Main Breathing Muscle

Located just beneath the xiphoid process, the diaphragm is a large, dome-shaped muscle crucial for breathing. It separates the chest and abdominal cavities, attaching to the sternum, lower ribs, and spine. The diaphragm contracts during inhalation and relaxes during exhalation. It also assists in functions like urination and preventing acid reflux. Irritation can cause hiccups, while injury can lead to shortness of breath.

The Epigastric Region: Top of the Abdomen

The epigastric region is the upper-central part of the abdomen. It contains several organs, such as the stomach, parts of the liver, the pancreas, and part of the spleen. Pain here can indicate conditions like GERD or ulcers.

Comparison of Structures Below the Chest


Feature	Xiphoid Process	Diaphragm	Epigastric Region
Type of Structure	Small, bony projection of the sternum	Large, dome-shaped skeletal muscle	Area of the upper-central abdomen
Primary Function	Muscle attachment site; landmark for CPR	Primary muscle for respiration (breathing)	Houses vital digestive and other organs
Key Location	Inferior tip of the sternum	Separates thoracic and abdominal cavities	Above the belly button, below the rib cage
Common Associated Issues	Pain (xiphodynia) from trauma or strain	Hiccups (irritation), weakness (nerve damage)	Pain from GERD, ulcers, or organ-related issues

Conclusion

The area below your chest includes the xiphoid process, the diaphragm, and the epigastric region, each with unique features and roles. Recognizing these components is important for identifying potential health issues. Any persistent or severe pain in this area requires medical evaluation due to the presence of critical organs. For more information on the diaphragm, you can refer to {Link: Cleveland Clinic https://my.clevelandclinic.org/health/body/21578-diaphragm}.

Understanding Symptoms and Treatment

What are the main causes of pain in the area below the chest?

Pain can stem from the xiphoid process, diaphragm, or issues in the epigastric region like GERD or ulcers. Heart-related pain can also spread to this area.

Can you break the xiphoid process?

Fracturing the xiphoid process is rare but possible from trauma or pressure during CPR. Severe fractures may need surgery to protect organs.

What is xiphoid process syndrome?

Also called xiphodynia, this involves painful swelling of the xiphoid process, potentially radiating to other areas. It can be triggered by trauma or strain.

What happens if the diaphragm is injured?

Diaphragm injury can cause breathing difficulty and chest pain, particularly when lying down. Nerve damage or hernias can also impact function.

Why do I get hiccups below my chest?

Hiccups result from involuntary spasms of the diaphragm muscle. Irritation can cause these contractions.

How can I tell if my pain is related to the xiphoid process or another issue?

Given the multiple possible causes, including serious conditions like heart attacks, medical evaluation is essential. Imaging can help distinguish xiphoid pain from other issues.

What is the purpose of the xiphoid process since it can be removed?

The xiphoid process is an attachment point for muscles. Though it has minor function and can be removed in rare surgical cases to protect organs, it is not considered essential.

Frequently Asked Questions

Pain can be caused by various issues, including strain or inflammation of the xiphoid process, gastroesophageal reflux disease (GERD), peptic ulcers, pancreatitis, or irritation of the diaphragm. Pain originating from the heart can also radiate to this area.

Yes, it is possible, though rare, to fracture the xiphoid process, most commonly from acute chest trauma or heavy pressure applied during CPR. Minor damage can often heal on its own, but a severe fracture might require surgical removal to prevent damage to surrounding organs.

Also known as xiphodynia, this is a painful swelling or tenderness of the xiphoid process that can sometimes radiate to the chest, abdomen, or arms. It can be triggered by trauma, heavy lifting, or underlying inflammatory conditions like arthritis.

An injured diaphragm can lead to difficulty breathing and chest pain, especially when lying down. Damage to the nerves controlling the diaphragm or hiatal hernias can also affect its function.

Hiccups are caused by involuntary contractions or spasms of the diaphragm muscle, which separates the chest and abdominal cavities. Irritation to the diaphragm can cause these repeated, involuntary contractions.

Since pain in this area can have multiple causes, including heart attacks, it's crucial to consult a doctor for diagnosis. Medical imaging like X-rays, MRI, or CT scans can help differentiate xiphoid pain from more serious conditions.

Although classified as a vestigial structure with minor function, the xiphoid process serves as an important attachment point for the diaphragm and abdominal muscles. It is only removed surgically in rare cases where a fracture poses a risk to internal organs.

The epigastric region of the abdomen contains several organs, including the stomach, parts of the liver, the pancreas, and the spleen.