Dyspnoea

Breathing is normally invisible to us. Dyspnoea is what happens when it stops being so — a feeling of air hunger, of tightness, or of effort out of proportion to what is being done. Breathlessness climbing three flights of stairs is physiology. Breathlessness on the level, at a pace that was comfortable last month, is a symptom.

What it points to

• Lungs — asthmaAsthmaAsthma is a long-term condition in which the airways are inflamed and tighten in response to triggers, causing wheeze, cough, chest tightness and breathlessness that come and go. It is controllable in almost everyone with the right treatment used correctly.Read the full definition, COPD, a chest infection, tuberculosis, fluid around the lung. Usually with cough, wheeze or sputum, and often worse on exertion.
• Heart — heart failure and valve disease. Characteristically worse lying flat, waking a person at night, and coming with ankle oedemaOedemaOedema is swelling caused by fluid collecting in the tissues, most often seen in the ankles and legs. It is a sign rather than a diagnosis, and what matters is the reason behind it.Read the full definition.
• Blood — anaemiaAnaemiaAnaemia means the blood carries less haemoglobin than it should, so less oxygen reaches the tissues. It usually shows itself as tiredness, breathlessness on exertion and pallor, and in Pakistan the commonest cause by a wide margin is a shortage of iron.Read the full definition delivers less oxygen with each beat, so effort is needed sooner. Common here and easily missed.
• Anxiety — real breathlessness, often with tingling in the fingers and around the mouth, and typically at rest rather than on exertion. It is a diagnosis made after the others have been considered, not instead of considering them.
• Weight, deconditioning and pregnancy, all of which raise the work of breathing without any disease being present.

Assessment usually starts with an examination, a pulse oximeterPulse oximeterA pulse oximeter is the clip placed on a fingertip to measure how much oxygen the blood is carrying, shown as a percentage. A reading of 95% or above is normal for most healthy adults.Read the full definition reading, a complete blood countComplete blood countA complete blood count measures the three families of cell in blood: red cells that carry oxygen, white cells that fight infection, and platelets that clot. It is the commonest blood test ordered anywhere and the usual first step in tiredness, fever, bruising or bleeding.Read the full definition, a chest x rayX-rayAn X-ray uses a small dose of radiation to produce an image, and it is best at showing bone and the chest. It is quick, widely available and usually the first imaging test requested.Read the full definition, an ecgECGAn ECG records the heart's electrical activity through stickers placed on the chest and limbs, printing it as a tracing. It takes a few minutes, is painless and involves no radiation, and it is the first test in chest pain, palpitations and blackouts.Read the full definition and often spirometrySpirometrySpirometry measures how much air you can breathe out and how fast, by blowing hard into a machine. It is the test that distinguishes asthma from COPD and tracks how well either is controlled.Read the full definition. Bring a clear account of what you can no longer do — how many stairs, how far on the flat — because that history describes the severity better than any single measurement.