Possible causes | Chest discomfort | Cardiology Made Clear with Dr. Freeman

← Chest discomfort: the short explanation

All 6 sections, including text and pictures · 26 pages

What should I do now?

Call 911

Call 911 for new or unexplained chest pressure that persists or returns, severe trouble breathing, collapse without normal recovery, or sudden face/arm weakness or trouble speaking. Do not drive yourself.

Contact your care team

New or changing chest symptoms need prompt assessment. Ongoing or recurrent concerning discomfort belongs on the emergency pathway.

Keep your care plan

For an established diagnosis, follow your written symptom plan and keep follow-up appointments.

Patient summaries & logs →

SECTION 2

Section 2: What can cause chest discomfort?

Chest discomfort can come from the heart, lungs, digestive system, muscles, or other structures. The sensation alone cannot reliably identify the cause.

1. Reduced blood flow to the heart

Coronary artery disease

Plaque narrows the arteries supplying the heart. When the heart muscle does not receive enough oxygen-rich blood, it can cause discomfort called angina.

Realistic cutaway comparison of a normal coronary artery with increasing plaque narrowing. — Plaque buildup can narrow the channel supplying blood to heart muscle. If blood flow cannot meet the heart’s needs, angina may occur. These are illustrative examples, not stages every patient passes through.

Heart attack

A sudden interruption of blood flow damages heart muscle, often after a plaque breaks open and a clot forms.

A plaque breaks open, a blood clot forms, and blood flow to an area of heart muscle is blocked. — A clot at a ruptured plaque can block oxygen-rich blood and cause a heart attack.

Coronary artery spasm

An artery temporarily tightens, reducing blood flow to heart muscle and causing angina.

A relaxed coronary artery compared with an artery during spasm, showing muscular contraction and reduced blood flow. — A temporary tightening of a coronary artery can reduce blood flow. The illustration shows spasm without a plaque blockage; spasm can also occur in patients who have plaque.

Small-vessel disease

The heart’s smaller blood vessels do not regulate blood flow normally. Heart-related discomfort can occur even without a major blockage in a large coronary artery.

An open large coronary artery with magnified healthy tiny vessels compared with tiny vessels that do not widen normally. — Problems in the heart’s tiny vessels can limit oxygen delivery and cause angina, even when the larger arteries are open. This shows one simplified example; mechanisms vary.

2. Other heart conditions

Inflammation around the heart, called pericarditis, can cause chest pain. Certain valve problems or fast heart rhythms can also cause discomfort.

3. Causes outside the heart

Examples include:

Digestive problems: Acid reflux or spasms of the esophagus.
Chest-wall problems: Muscle strain or inflammation where ribs meet the breastbone.
Lung problems: Pneumonia, inflammation around the lungs, a collapsed lung, or a blood clot in the lungs.
Anxiety or panic attacks: These can cause chest discomfort and rapid breathing.

A tear in the wall of the aorta—the body’s main artery—is another serious cause. Some causes outside the heart are also life-threatening emergencies.

Avoid diagnosing yourself by the feeling alone

Burning discomfort is not always reflux, and sharp pain is not always harmless. New or unexplained symptoms should be assessed rather than automatically attributed to indigestion, muscle pain, or anxiety.

Sources & further readingNIH: Angina treatment AHA: Heart attack warning signs Mayo Clinic: Chest pain evaluation and treatment NIH: Living with a stent

Updated October 2026. Educational information; your own care plan may differ. Medical illustrations are simplified examples for teaching.