Feeling winded after running, climbing several flights of stairs, or doing strenuous exercise can be completely normal. But what if you become short of breath while walking across a parking lot, doing housework, climbing a single flight of stairs, or performing activities that normally do not bother you?

Shortness of breath with exertion—also called dyspnea on exertion or exertional dyspnea—means feeling unusually breathless during physical activity. It can have relatively harmless explanations, such as being out of shape or exercising harder than usual, but it can also be associated with conditions involving the lungs, heart, blood, or other body systems.

The most important questions are not simply “Am I short of breath?” but rather:

• Is this new?
• Is it getting worse?
• How much activity does it take to trigger it?
• Does it improve with rest?
• Are there other symptoms such as chest pain, palpitations, dizziness, fever, wheezing, or leg swelling?

Those details can help determine whether breathlessness may be relatively benign or deserves prompt medical evaluation.

Important: Severe or sudden unexplained shortness of breath—particularly when accompanied by chest pain, fainting, blue lips or nails, confusion, or other serious symptoms—can be a medical emergency. Call 911 or seek emergency medical care rather than attempting to diagnose the cause yourself.

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What Is Shortness of Breath With Exertion?

Shortness of breath is medically known as dyspnea. People describe it differently. Some feel as though they cannot take a deep enough breath. Others describe chest tightness, rapid breathing, air hunger, or the sensation that they simply cannot get enough air.

Dyspnea on exertion means that these symptoms appear or become worse with physical activity.

Examples include becoming unusually winded while:

• walking
• climbing stairs
• carrying groceries
• exercising
• cleaning the house
• doing yard work
• walking uphill
• performing normal work activities

The amount of exertion required to trigger symptoms matters.

Someone who becomes winded only after strenuous exercise is very different from someone who suddenly becomes breathless walking from the bedroom to the bathroom.

In fact, clinicians evaluating dyspnea often consider the level of activity required to produce symptoms and whether that level has changed from the person’s normal baseline.

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Is It Normal to Get Short of Breath During Exercise?

Sometimes.

Exercise increases your muscles’ demand for oxygen. Your heart beats faster, and your breathing rate increases to meet that demand.

A person may therefore become temporarily winded after strenuous exercise without having a disease.

Shortness of breath may also become more noticeable with factors such as strenuous physical activity, higher altitude, extreme temperatures, weight gain, stress, or poor conditioning.

What deserves more attention is a change from your normal ability.

For example, consider someone who has walked two miles regularly for years but suddenly begins stopping for breath after a few blocks.

That change is more significant than a sedentary person becoming winded after unexpectedly attempting a difficult hike.

Likewise, breathlessness triggered by progressively less activity deserves medical evaluation.

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What Causes Shortness of Breath With Exertion?

There is no single cause of exertional dyspnea.

Because breathing depends on the lungs taking in oxygen, the cardiovascular system circulating oxygenated blood, and the body using that oxygen appropriately, problems in several different systems can produce similar symptoms.

Common and important possibilities include the following.

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1. Physical Deconditioning

One relatively common explanation is deconditioning, meaning the body has become less accustomed to physical activity.

This can occur after:

• prolonged inactivity
• illness
• hospitalization
• sedentary lifestyle
• significant reduction in exercise
• weight gain

Physical deconditioning is recognized as a common contributor to dyspnea.

However, it is important not to automatically assume that new breathlessness is simply because you are “out of shape.”

New, unexplained, persistent, or worsening shortness of breath should be evaluated—especially when the degree of breathlessness seems disproportionate to the activity.

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2. Asthma

Asthma can cause the airways to narrow and become inflamed, making airflow more difficult.

Some people experience symptoms primarily during or after physical activity.

Possible symptoms include:

• shortness of breath
• wheezing
• coughing
• chest tightness
• difficulty taking a full breath

Exercise, cold air, allergens, and respiratory infections can trigger asthma symptoms in susceptible individuals.

Someone with recurrent breathlessness, wheezing, or coughing during exercise may need evaluation for asthma or another airway disorder.

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3. Respiratory Infection or Pneumonia

Respiratory infections can temporarily make physical activity much more difficult.

Pneumonia and other lung infections are recognized causes of shortness of breath.

Clues that an infection may be contributing include:

• cough
• fever
• chills
• fatigue
• sputum or phlegm
• chest discomfort
• worsening breathing

A person who normally walks without difficulty may suddenly become exhausted or breathless because the lungs are not functioning normally during an infection. Also see Chest Congestion: When to Worry.

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4. Chronic Obstructive Pulmonary Disease (COPD)

COPD is a chronic lung disease that limits airflow and can progressively make physical activity more difficult.

Breathlessness may initially be most noticeable during exercise. As disease progresses, less strenuous activities may trigger symptoms.

Other possible symptoms include:

• chronic cough
• wheezing
• mucus production
• decreased exercise tolerance
• recurrent respiratory infections

Smoking is a major risk factor for COPD, and worsening shortness of breath can be one of the manifestations of long-term smoking-related lung damage.

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5. Anemia

Not every cause of shortness of breath comes from the lungs.

Anemia means that the blood has an insufficient amount of healthy red blood cells or hemoglobin to adequately transport oxygen.

The lungs may be working normally, but the body’s ability to carry oxygen is impaired.

Possible symptoms can include:

• fatigue
• weakness
• exertional shortness of breath
• dizziness
• reduced exercise tolerance
• palpitations

Anemia is among the recognized non-pulmonary causes of dyspnea.

Someone experiencing unexplained shortness of breath together with persistent fatigue may therefore need more than just a lung evaluation.

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Shortness of Breath and Fatigue

Shortness of breath and fatigue frequently occur together because many conditions that impair oxygen delivery or increase the body’s workload can cause both symptoms.

Possible causes range from relatively minor conditions to significant cardiopulmonary disease.

Examples include:

• viral illness
• anemia
• physical deconditioning
• asthma
• COPD
• pneumonia
• heart disease
• heart failure

The duration and progression matter.

Feeling tired and winded while recovering from an illness is different from experiencing steadily worsening fatigue and breathlessness for several weeks without an obvious explanation.

Persistent symptoms should be evaluated rather than attributed automatically to age, stress, or poor conditioning.

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6. Heart Rhythm Problems

An abnormal heart rhythm can sometimes reduce how efficiently the heart pumps blood during activity.

This may produce:

• palpitations
• racing heartbeat
• skipped-beat sensations
• shortness of breath
• dizziness
• weakness
• exercise intolerance

Arrhythmias are among the cardiac conditions associated with acute shortness of breath.

Shortness of Breath With Palpitations

Feeling your heart race after strenuous exercise can be normal.

However, recurrent or unexplained palpitations occurring together with shortness of breath deserve more attention—particularly when symptoms are associated with dizziness, fainting, chest discomfort, or reduced exercise tolerance.

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7. Heart Disease

The heart and lungs work closely together.

If the heart cannot effectively circulate blood during increased physical demand, exertion can reveal the problem before symptoms become obvious at rest.

Cardiac causes of dyspnea include conditions such as myocardial ischemia, cardiomyopathy, arrhythmias, and heart failure.

Possible warning symptoms include:

• chest pressure or discomfort
• shortness of breath with activity
• unexplained fatigue
• dizziness
• nausea
• sweating
• reduced exercise tolerance

Not everyone experiencing a heart problem develops dramatic chest pain.

That is one reason new exertional shortness of breath should not simply be ignored when it represents a significant change from baseline.

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8. Heart Failure

Heart failure does not mean that the heart has completely stopped working. Rather, the heart cannot pump or fill effectively enough to meet the body’s needs.

Breathlessness may initially occur with activity.

Other clues can include:

• swelling of the feet or ankles
• reduced exercise tolerance
• unusual fatigue
• shortness of breath when lying flat
• waking during the night feeling short of breath
• weight gain related to fluid accumulation

Dependent edema and difficulty breathing while lying flat are important clues clinicians consider when evaluating dyspnea for possible heart failure.

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Shortness of Breath With Leg Swelling

This combination deserves special attention.

Leg swelling has many possible causes, and many cases are not emergencies. But shortness of breath occurring together with swelling can sometimes point toward cardiovascular disease or, in certain circumstances, a blood clot.

For example, heart failure can produce both breathlessness and swelling of the lower extremities.

Alternatively, a blood clot in a deep leg vein—known as a deep vein thrombosis (DVT)—can potentially travel to the lungs and become a pulmonary embolism (PE).

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9. Pulmonary Embolism

A pulmonary embolism occurs when an artery in the lungs becomes blocked, commonly by a blood clot that traveled from elsewhere in the body.

This can be life-threatening.

Possible symptoms include:

• sudden shortness of breath
• rapid breathing
• rapid heartbeat
• sharp chest pain
• dizziness or fainting
• coughing, sometimes with blood

Risk factors can include recent surgery or hospitalization, prolonged immobilization, a history of DVT, certain cancers, pregnancy, and estrogen-containing medications, among others.

New shortness of breath following prolonged inactivity, surgery, illness, injury, or a long car or airplane trip deserves particular attention. Mayo Clinic specifically recommends emergency evaluation for certain new-onset breathlessness in these circumstances because of the possibility of a pulmonary embolism.

Do not attempt to rule out a pulmonary embolism based only on how severe the symptoms feel.

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10. Pneumothorax

A pneumothorax, commonly called a collapsed lung, occurs when air enters the space between the lung and chest wall.

It may cause:

• sudden shortness of breath
• sharp chest pain
• rapid breathing
• decreased breath sounds on the affected side

It may occur following an injury but can also happen spontaneously.

Sudden unexplained chest pain with difficulty breathing requires urgent medical evaluation.

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11. Anxiety and Panic

Anxiety can cause genuine physical changes in breathing.

A panic episode may cause:

• rapid breathing
• air hunger
• chest tightness
• tingling
• trembling
• palpitations
• dizziness
• a feeling that something terrible is happening

Anxiety and panic disorders are recognized causes of shortness of breath.

However, there is an important safety principle:

New shortness of breath should not automatically be diagnosed as anxiety simply because a person feels anxious.

Difficulty breathing itself can cause anxiety.

Medical causes should be considered based on the person’s symptoms, history, risk factors, vital signs, and examination.

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When Should You Worry About Shortness of Breath With Exertion?

Pay attention to change from baseline.

You should consider medical evaluation when shortness of breath:

• is new or unexplained
• is becoming progressively worse
• occurs with increasingly minor activity
• interferes with normal daily activities
• repeatedly occurs during ordinary walking
• occurs with wheezing
• occurs with persistent cough or fever
• occurs with unusual fatigue
• occurs with palpitations
• accompanies swelling of the feet or ankles
• becomes worse when lying flat

The American Lung Association notes that breathlessness that occurs frequently, begins suddenly, or interferes with normal daily activities warrants attention. Also see Shortness of Breath: When to Worry.

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When Is Shortness of Breath an Emergency?

Some combinations of symptoms should not wait for a routine appointment.

Call 911 or seek emergency care for severe or sudden shortness of breath, especially when accompanied by:

• chest pain or pressure
• fainting
• blue or gray lips or nails
• confusion or altered mental status
• severe difficulty breathing
• sudden inability to function normally
• significant dizziness
• other rapidly worsening symptoms

Sudden severe dyspnea accompanied by chest pain, fainting, nausea, cyanosis, or altered alertness may represent a serious cardiovascular or pulmonary emergency.

Emergency conditions can include pulmonary embolism, heart attack, severe asthma, pneumothorax, severe pneumonia, heart failure, anaphylaxis, airway obstruction, and other potentially dangerous illnesses.

When severe breathing difficulty is occurring, do not drive yourself if doing so would be unsafe. Call 911.

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How Is Shortness of Breath With Exertion Evaluated?

Because so many conditions can produce dyspnea, there is no single test that diagnoses every case.

Evaluation begins with the history.

A healthcare professional may ask:

• When did the symptoms begin?
• Did they start suddenly or gradually?
• What activity triggers them?
• How far can you walk before becoming breathless?
• Do symptoms occur at rest?
• Do they improve with rest?
• Is there chest pain?
• Is there cough, fever, or wheezing?
• Are there palpitations?
• Is there leg swelling?
• Do symptoms worsen when lying flat?
• Have you recently traveled, had surgery, or been immobilized?
• Do you smoke or vape?
• Do you have asthma, COPD, heart disease, or anemia?

The physical examination commonly includes evaluating breathing, heart and lung sounds, circulation, and oxygenation.

Depending on the situation, additional testing may include:

• pulse oximetry
• electrocardiogram (ECG/EKG)
• chest X-ray
• blood tests
• pulmonary function testing
• echocardiogram
• CT imaging
• testing for pulmonary embolism when clinically indicated

The American Lung Association notes that evaluation can involve blood tests, chest imaging, pulmonary function testing, and echocardiography depending on the suspected cause.

Merck Manual similarly describes pulse oximetry, chest radiography, ECG, and additional targeted testing as components of dyspnea evaluation depending on the clinical presentation.

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Can You Check Your Oxygen Level at Home?

A pulse oximeter can estimate oxygen saturation, but the number should not be used by itself to decide whether breathing difficulty is dangerous.

A person can have significant illness despite a reading that initially appears acceptable, and consumer devices have limitations.

Symptoms and the overall clinical situation matter.

Severe breathing difficulty, chest pain, fainting, confusion, or other emergency warning signs should prompt emergency care regardless of whether a home device appears reassuring.

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How Is Shortness of Breath With Exertion Treated?

There is no universal treatment because dyspnea is a symptom, not a diagnosis.

Treatment depends on the underlying cause.

For example:

• Asthma may require inhaled medications and trigger management.
• Pneumonia may require supportive care and, when bacterial, appropriate antibiotics.
• Anemia requires identifying and treating its cause.
• Heart failure requires cardiovascular management and treatment of fluid overload and underlying cardiac disease.
• Arrhythmias require management based on the specific rhythm and clinical situation.
• COPD treatment may include inhaled medications, smoking cessation, pulmonary rehabilitation, and other therapies.
• Pulmonary embolism requires urgent medical treatment.
• Physical deconditioning may improve through an appropriately designed activity program once dangerous causes have been excluded.

This is why treating unexplained breathlessness without determining its cause can be problematic.

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Should You Keep Exercising if You Are Short of Breath?

Mild breathlessness during expected strenuous exercise can be normal.

But new or unexplained exertional dyspnea should not simply be “pushed through.”

Stop activity and seek appropriate evaluation if breathlessness is:

• unusually severe
• dramatically different from normal
• accompanied by chest pain
• associated with fainting or near-fainting
• associated with significant dizziness
• accompanied by severe palpitations
• worsening rapidly

For persistent non-emergency symptoms, discuss appropriate exercise with a healthcare professional before substantially increasing activity.

Regular exercise can ultimately improve conditioning and reduce some forms of chronic breathlessness, but the underlying cause should first be understood when symptoms are unexplained.

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Urgent Care, Primary Care, or Emergency Room?

The appropriate setting depends on severity and associated symptoms.

Primary care may be appropriate

For mild, stable, persistent breathlessness without emergency warning signs, particularly when symptoms have developed gradually, a primary care clinician can begin the evaluation and coordinate additional testing or specialist referral.

Urgent care may be appropriate

Urgent care may be reasonable for certain new but stable respiratory symptoms when the person is not experiencing severe distress or other emergency warning signs.

Depending on the facility, evaluation may include vital signs, oxygen saturation, physical examination, ECG, chest X-ray, or other testing.

However, urgent care capabilities vary considerably.

If evaluation raises concern for a condition requiring advanced imaging, cardiac testing, prolonged monitoring, or hospital-level treatment, transfer to an emergency department may be necessary.

Emergency department

Go directly to an emergency department or call 911 for severe breathing difficulty or concerning associated symptoms such as chest pain, fainting, cyanosis, confusion, or sudden severe deterioration.

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Frequently Asked Questions

Why do I get short of breath just walking?

Possible explanations range from physical deconditioning to asthma, COPD, anemia, heart disease, infection, obesity, and other conditions.

The important consideration is whether this is normal for you.

If walking previously caused no difficulty and you have developed new breathlessness, consider medical evaluation rather than assuming you are simply out of shape.

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Why am I suddenly getting winded climbing stairs?

Stairs require substantially more cardiovascular and respiratory effort than level walking, so some breathlessness can be normal.

However, a noticeable decline from your previous ability—particularly if accompanied by chest discomfort, dizziness, palpitations, wheezing, or unusual fatigue—deserves evaluation.

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Can anemia make you short of breath during exercise?

Yes.

Anemia can reduce the blood’s ability to carry oxygen, which can contribute to fatigue, weakness, dizziness, reduced exercise tolerance, and exertional breathlessness.

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Can anxiety cause shortness of breath?

Yes. Anxiety and panic can produce genuine shortness of breath and rapid breathing.

But unexplained new breathing difficulty should not automatically be attributed to anxiety without considering medical causes.

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Is shortness of breath with leg swelling dangerous?

It can be.

The combination can occur with conditions such as heart failure. In certain situations, leg symptoms followed by sudden shortness of breath can also raise concern for DVT and pulmonary embolism. Also see Leg Swelling: When to Worry.

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What does dyspnea on exertion mean?

Dyspnea is the medical term for uncomfortable or difficult breathing. Dyspnea on exertion simply means that the breathlessness occurs or worsens during physical activity.

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The Bottom Line

Shortness of breath with exertion can range from normal breathlessness after strenuous exercise to an early warning sign of significant heart or lung disease.

The most useful question is often:

“Is this different from what is normal for me?”

Becoming winded after an intense workout may be expected. Becoming newly short of breath while walking across the room is very different.

Pay particular attention when breathlessness is:

• new
• unexplained
• progressively worsening
• triggered by increasingly minor activity
• associated with chest pain
• associated with palpitations
• accompanied by leg swelling
• associated with fainting or severe dizziness
• present at rest

Severe or sudden breathing difficulty, particularly with chest pain, fainting, cyanosis, confusion, or other serious symptoms, requires emergency evaluation.

For less severe but persistent or unexplained symptoms, medical evaluation can help determine whether the cause is related to the lungs, heart, blood, physical conditioning, or another condition.

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References

• American Lung Association — Shortness of Breath
• Mayo Clinic — Shortness of Breath: Causes
• Mayo Clinic — Shortness of Breath: When to See a Doctor
• MedlinePlus — Breathing Problems
• Merck Manual Professional — Dyspnea

Medical disclaimer: This article is for general educational purposes and is not a substitute for individualized medical advice, diagnosis, or treatment. If you are experiencing severe or sudden difficulty breathing or other symptoms of a medical emergency, call 911 or seek emergency medical care.