What is Causing my Breathlessness?

Breathlessness is very common and is one of the main reasons people see a doctor. The medical term for it is dyspnoea. Breathlessness or shortness of breath is a common clinical manifestation of many underlying conditions.

So how do we define it?

• Dyspnea is an individual’s interpretation of breathing discomfort. It is a subjective symptom that can be acute or chronic.
• Acute dyspnoea comes on over hours to days and can signal a serious or life-threatening condition, so it needs prompt assessment. Sometimes, chest tightness is an accompaniment of acute dyspnea.
• Chronic dyspnoea is shortness of breath that lasts for weeks or longer.

There is no single cause. Dyspnea may indicate a problem in the lungs, heart, or a combination of both. It can also be due to anemia, anxiety, drugs, malignancy, renal failure, thyroid disease, diabetes, sepsis, pregnancy, and trauma!

When is breathlessness an emergency?

Call 995 or go to the nearest Emergency Department straight away if breathlessness:

• comes on suddenly and is severe, or you cannot speak in full sentences
• comes with chest pain, pressure or tightness, sweating or nausea
• comes with fainting, confusion, or blue or grey lips or fingertips
• starts after a long flight, surgery or bed rest, especially with a painful, swollen calf or coughing up blood
• comes with swelling of the face, lips or throat after a food, insect sting or medicine

Do not drive yourself: call 995 or have someone take you. If the breathlessness is new but mild, see your doctor within a few days rather than waiting for it to pass.

I’ve broken down the cause into 3 areas:

1. Lung (respiratory) causes
2. Heart causes
3. Others

1. Lung causes of breathlessness

Asthma. Asthma is inflammation and narrowing of the lung airways, which can be triggered by allergens, exercise, infections and irritants such as smoke. People with asthma exhibit noisy wheezing, high breathing rate, and shortness of breath.

COPD. Chronic Obstructive Pulmonary Diseases (COPD) is a group of lung problems characterized by chronic inflammation and obstruction of the lower airways. Bronchitis and emphysema are examples of COPD. Difficulty of breathing and chronic productive cough are the classic signs of COPD.

Pneumonia. Pneumonia is the inflammation of the lungs marked by cough, fever, and pain on deep breathing. Dyspnea is also a predominant clinical manifestation, particularly in older people aged 65 and above, diffused type of pneumonia and viral pneumonia.

Pulmonary embolism. Pulmonary embolism is a blockage in a lung artery, usually by a blood clot that has travelled from the legs. It can be life-threatening without prompt treatment. Risk is higher after surgery or long periods of inactivity, and in people with clotting problems. Sudden shortness of breath, shallow breathing, chest pain, increased heart rate, and coughing up blood are common signs and symptoms of pulmonary embolism.

2. Heart causes of breathlessness

Heart failure. Heart failure is a state when the heart loses its ability to pump blood effectively throughout the body. People with heart failure may be breathless on exertion or when lying down, and may have swollen legs and ankles, rapid weight gain from fluid, and tiredness. Heart failure is often a complication of other health conditions such as high blood pressure and heart attacks.

Coronary heart disease (CHD). Coronary heart disease is a condition when the heart receives deficient blood supply as a result of blocked coronary arteries (the main blood vessels supplying the heart). The blockage is caused by fatty-build up over a period of time. CHD is a serious health disorder since it can cut off the blood supply to the heart completely, leading to a heart attack. Chest pain (angina) is the classic sign of CHD, but breathlessness on exertion can also be a sign, sometimes instead of chest pain.

3. Other causes of breathlessness

Anaemia. Anaemia refers to low red blood cells in the body. Red blood cells carry oxygen to the body’s tissues. Because the tissues and organs receive less oxygen, people with anaemia exhibit shortness of breath, fatigue, and irregular heartbeat.

Anxiety and panic. Dyspnea can be psychological. Like pain, dyspnea can be influenced by the state of mind. People who panic and feel anxious may struggle to breathe. Difficulty of breathing caused by psychological illness is called psychogenic dyspnea.

Drugs. Some medicines can narrow the airways in susceptible people: beta-blockers in people with asthma or COPD, and aspirin or other anti-inflammatory painkillers (NSAIDs) in some people with asthma. Never stop a prescribed medicine without speaking to your doctor.

Cancer. People with cancer may present with shortness of breath as a complication of a disease or a side effect of a treatment such as chemotherapy. They also suffer more pronounced dyspnea upon exertion or physical activity.

Kidney failure. People with late-stage kidney failure may struggle to breathe. Shortness of breath in kidney failure is a result of fluid accumulation in the lungs. People with end-stage kidney disease lose their ability to excrete waste products leading to fluid build-up.

Thyroid disease. Both hyperthyroidism and hypothyroidism affect the respiratory system. The underactive thyroid gland (hypothyroidism) causes respiratory muscle weakness and reduces lung function. On the other hand, an overactive thyroid (hyperthyroidism) can increase respiratory drive, particularly on exertion.

Diabetic ketoacidosis (DKA). Diabetic ketoacidosis is a serious complication of diabetes marked by an increased level of ketones in the body. Too many ketones can make the body acidic, which may impair significant bodily functions. DKA can cause deep, rapid breathing as the body tries to correct the acid build-up by breathing out more carbon dioxide.

Sepsis. Sepsis is a life-threatening reaction of the body to an infection, which can damage organs. It is a medical emergency that can lead to multiple organ failure or even death. Shortness of breath and altered mental status are systemic clinical symptoms of people with severe sepsis.

Pregnancy. Mild breathlessness is common in pregnancy, partly due to hormonal changes and, later, the growing womb pressing on the diaphragm. Sudden or severe breathlessness, chest pain, or breathlessness when lying flat in pregnancy needs urgent assessment.

Trauma. Dyspnea is a common presenting symptom in a thoracic emergency requiring immediate treatment. For example, people with pneumothorax or a collapsed lung manifest sudden shortness of breath with one-sided chest pain.

Other Causes. There are many other causes of dyspnea. Any trauma, malformation, cancer, and disease in the ear, throat, and nose can affect breathing resulting in dyspnea. Neuromuscular conditions, such as motor neurone disease or myasthenia gravis, can weaken the breathing muscles and cause difficulty breathing.

Heart or lungs? Clues your doctor looks for

The pattern of breathlessness gives useful clues, but no single feature is conclusive.

• Breathless when lying flat, or waking at night gasping for air. This is typical of heart failure, where fluid builds up in the lungs. Needing extra pillows to sleep, swollen ankles or rapid weight gain make it more likely.
• Breathless on effort you used to manage, such as climbing stairs. This can be a sign of narrowed heart arteries, sometimes in place of chest pain, or of a valve problem such as aortic stenosis. It is also seen with COPD, anaemia and loss of fitness.
• Breathlessness with palpitations or an irregular pulse. A rhythm problem such as atrial fibrillation can reduce how well the heart pumps.
• Wheeze, cough or phlegm point more towards asthma, COPD or a chest infection, especially in smokers.
• Loud snoring and daytime sleepiness suggest obstructive sleep apnoea, which is linked with high blood pressure and heart rhythm problems.

Being overweight or unfit commonly causes breathlessness on exertion, but this should only be assumed once other causes are ruled out.

Tests to find the cause

Your doctor will choose tests based on your history and examination. Common ones include:

• Electrocardiogram (ECG): records the heart’s rhythm and can show signs of a previous heart attack or strain on the heart.
• Echocardiogram: an ultrasound scan showing how well the heart pumps and whether the valves work normally.
• Blood tests: a full blood count for anaemia, kidney and thyroid function, and a natriuretic peptide (BNP or NT-proBNP), which rises when the heart is under strain. In urgent cases, troponin or D-dimer may be checked.
• Chest X-ray: looks for fluid, infection, a collapsed lung or an enlarged heart.
• Lung function tests (spirometry): measure how much and how fast you can breathe out, to help diagnose asthma and COPD.
• Cardiopulmonary exercise test: measures breathing, heart rate and oxygen use during exercise, and can help when the cause is unclear.

Conclusion

Dyspnea is a complex symptom that may be common for healthy individuals, such as when performing exercise. Similarly, people who experience fear, anxiety, or strong emotion may seem breathless. Dyspnea has numerous potential causes therefore, a good physical examination, precise history taken by your cardiologist, and tests play a key role in making the correct diagnosis and identifying the cause.

Frequently asked questions

What is the medical term for shortness of breath?

The medical term is dyspnoea (spelt dyspnea in American English). Doctors often shorten shortness of breath to “SOB”, and “SOBOE” means shortness of breath on exertion. Breathlessness when lying flat is called orthopnoea.

Can breathlessness be a sign of a heart attack?

Yes. Some people, particularly women, older adults and people with diabetes, have breathlessness with little or no chest pain during a heart attack. Call 995 if breathlessness comes on suddenly with sweating, nausea, light-headedness or chest discomfort.

When should I see a cardiologist about breathlessness?

Consider a heart assessment if you are breathless with mild activity or when lying flat, have swollen ankles or palpitations, have been told you have a heart murmur, or have heart disease or risk factors such as high blood pressure, diabetes or smoking. Your GP can also arrange first tests and refer you.