Breathlessness on Exertion

Why do I get breathless when exerting myself?

Breathlessness on exertion, also known as dyspnea, can have various causes, including both cardiac and non-cardiac factors. Cardiac causes of breathlessness on exertion are often related to the heart’s inability to pump blood effectively, leading to reduced oxygen delivery to the body. Here are some common cardiac causes and the associated investigations:

Cardiac Causes

In heart failure, the heart is unable to pump blood efficiently, leading to fluid accumulation in the lungs (pulmonary edema) and causing breathlessness. Investigations may include:

  • Echocardiography: This ultrasound test provides detailed images of the heart’s structure and function.

2. Coronary Artery Disease (CAD)

Reduced blood flow to the heart muscle can result in angina or myocardial infarction (heart attack), leading to breathlessness. Investigations may include:

  • Electrocardiogram (ECG): Records the electrical activity of the heart.
  • Stress testing: Assesses how the heart responds to increased workload.
  • Coronary angiography: Uses contrast dye and X-rays to visualize the coronary arteries.

Malfunctioning heart valves can impair blood flow and lead to breathlessness. Investigations may include:

  • Echocardiography: To assess the structure and function of heart valves.
  • Cardiac catheterization: Measures pressures within the heart chambers.

4. Arrhythmias

Irregular heart rhythms can affect the heart’s pumping efficiency, leading to breathlessness. Investigations may include:

  • Electrocardiogram (ECG): To identify abnormal heart rhythms.
  • Holter monitor: Records continuous ECG over 24 to 48 hours.
  • Event monitor: Similar to a Holter monitor but worn for a more extended period, typically for several weeks. It is used when palpitations are infrequent.

Non-Cardiac Causes

Lung Disorders

Conditions like chronic obstructive pulmonary disease (COPD) can cause breathlessness. Pulmonary function tests may be conducted.


Low levels of red blood cells can reduce oxygen-carrying capacity. Blood tests, including a full blood count (FBC), can help diagnose anemia.


Excess weight can strain the respiratory system, causing breathlessness.

It's important to consult with a healthcare professional if you are experiencing breathlessness on exertion. They can perform a thorough evaluation, including a medical history, physical examination, and relevant tests to determine the underlying cause and formulate an appropriate treatment plan.

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