Shortness of Breath: Causes and When to Worry

What shortness of breath feels like

People describe dyspnea in different ways, and the description gives clues:

• "I can't get a full breath" or "air hunger": common in heart failure, lung scarring and anxiety
• "My chest is tight": typical of asthma
• "I have to work hard to breathe": COPD, asthma, obesity, neuromuscular weakness
• "I breathe faster and get winded easily": deconditioning, anemia, heart problems

Doctors also grade it by how much activity brings it on, for example the MRC dyspnea scale, from breathless only with strenuous exercise (grade 1) to too breathless to leave the house (grade 5).

Sudden shortness of breath: common causes

Gradual or long-term breathlessness

Shortness of breath when lying down

Orthopnea is breathlessness lying flat that improves when sitting up. It suggests heart failure, large amounts of fluid around the lungs, severe COPD, obesity or weakness of the diaphragm. Waking up gasping an hour or two after falling asleep (paroxysmal nocturnal dyspnea) is a classic heart failure symptom. See difficulty breathing when lying down.

Shortness of breath with exertion

Being breathless on stairs or walking is often the earliest sign of heart or lung disease, anemia or poor fitness. A change in what you can do (for example, previously managing three flights of stairs but now stopping after one) is more important than the breathlessness itself.

Other situations

• Pregnancy: mild breathlessness is common because of hormones and the growing womb. Sudden breathlessness, chest pain or breathlessness with a fast heart rate needs urgent assessment for a blood clot or heart problem.
• After COVID-19 or other infections: breathlessness can last weeks. Persistent breathlessness should be assessed.
• Children: fast breathing, ribs pulling in, grunting, nostril flaring or poor feeding in a baby need urgent care.

How doctors find the cause

Your doctor will ask how fast it came on, what brings it on, whether it is worse lying down, about cough, chest pain, wheeze, swelling, smoking, work exposures and medicines. They will check:

• oxygen saturation with a finger clip (pulse oximeter)
• breathing rate, heart rate and blood pressure
• chest sounds (wheeze, crackles), heart sounds and leg swelling

Tests may include:

• chest X-ray
• ECG and troponin blood test for heart causes
• blood tests: blood count for anemia, BNP for heart failure, D-dimer for blood clots, kidney and thyroid function
• spirometry for asthma and COPD
• echocardiogram (heart ultrasound)
• CT scan of the chest, including CT pulmonary angiography for suspected clots
• exercise testing for unexplained breathlessness

Treatment

Treatment targets the cause:

• Asthma and COPD: reliever and preventer inhalers, steroids for flares, and pulmonary rehabilitation for COPD
• Pneumonia: antibiotics if bacterial, and oxygen if levels are low
• Pulmonary embolism: blood-thinning medicines
• Heart failure: diuretics (water pills) to clear fluid, and medicines that strengthen the heart over time
• Anemia: iron or treating the cause of blood loss
• Panic and anxiety: breathing retraining, CBT and sometimes medicines
• Obesity and deconditioning: gradual exercise and weight loss

Things that help breathlessness

• Breathing techniques: pursed-lip breathing (breathe in through the nose, out slowly through pursed lips) and diaphragmatic breathing
• Positions: sitting leaning forward with arms resting on your knees or a table
• A handheld fan blowing cool air on the face reduces the sensation of breathlessness
• Pacing: break tasks into smaller steps
• Stopping smoking: the single most effective step for lung health
• Staying active within your limits, ideally through a rehabilitation program

Frequently asked questions

When should I worry about shortness of breath?

Seek emergency help if breathlessness is sudden or severe, you cannot speak in full sentences, your lips turn blue or gray, or it comes with chest pain, coughing blood, swelling of the face or confusion. See a doctor promptly for breathlessness that is gradually worsening or limiting what you can do.

What causes sudden shortness of breath?

Common sudden causes are an asthma attack, a chest infection, a blood clot in the lung, a heart attack, a collapsed lung, an allergic reaction and a panic attack. Many of these are serious, so sudden breathlessness should be assessed the same day.

Why am I short of breath when lying down?

Breathlessness lying flat often reflects fluid in the lungs from heart failure. It can also occur with severe COPD, obesity, a large pleural effusion or diaphragm weakness. Needing extra pillows or waking up gasping should be checked promptly.

Can anxiety cause shortness of breath?

Yes. Anxiety and panic attacks cause fast, shallow breathing, chest tightness, tingling in the fingers and lips, and a feeling of not getting enough air. Oxygen levels stay normal. Because heart and lung problems can feel similar, a first episode should be assessed by a doctor.

Is shortness of breath a sign of heart problems?

It can be. Heart failure, heart attacks, valve disease and abnormal heart rhythms all cause breathlessness, often on exertion or lying flat, sometimes with chest pain, swollen ankles or palpitations. An ECG, blood tests and an echocardiogram help check the heart.