Asthma and COPD: how they differ in cause, symptoms and treatment

What is asthma?

Asthma is a long-term condition that affects the airways. The NHS says the main symptoms are wheezing, coughing, shortness of breath and a tight chest, and that they often come and go.

Common triggers include exercise, cold air, air pollution and allergens such as pollen or dust. The NHS says the exact cause of asthma is not fully understood, but allergies, a family history of asthma or allergies, and early-life exposure to air pollution or cigarette smoke are among the factors linked with it.

During an asthma attack, sitting up and staying calm is part of the usual NHS advice while using the reliever inhaler as directed, and 999 should be called if there is no improvement.

What is COPD?

COPD, short for chronic obstructive pulmonary disease, is the name for a group of lung conditions that cause breathing difficulties. It includes emphysema and chronic bronchitis.

The NHS says the main cause is smoking, although it can sometimes affect people who have never smoked. Typical symptoms are breathlessness on exertion, a persistent chesty cough with phlegm, frequent chest infections and wheeze. They tend to get worse over time.

With COPD there can also be periods when symptoms suddenly get worse, known as a flare-up.

How do doctors tell them apart?

NICE says that when someone first presents with symptoms, untreated COPD and asthma can frequently be told apart from the person's history and an examination. NICE advises using features from the person's history and examination to help tell the two conditions apart.

Breathing tests help. Spirometry is a breathing test that supports a diagnosis of COPD, and lung function tests also form part of diagnosing asthma, although a normal result does not always rule asthma out. The site's spirometry page explains the test.

Because symptoms vary and breathing problems have more than one cause, the NHS notes that diagnosing asthma can take time.

How are the two treated?

The NHS says inhalers are the main treatment for asthma. Reliever inhalers ease symptoms when they occur, and preventer inhalers are used regularly to reduce them. An asthma action plan is usually agreed with a doctor or asthma nurse.

There is currently no cure for COPD, but treatment can help slow its progression and control symptoms, and for people who smoke, stopping smoking is the most important step. Treatment mainly relieves symptoms, with inhalers, and pulmonary rehabilitation may help people become more active.

When is breathlessness an emergency?

Asthma attacks can be life-threatening. During an asthma attack, the NHS says to call 999 if the person does not feel better after using their reliever inhaler as directed, if they feel worse at any time, or if they do not have an inhaler.

COPD symptoms can suddenly get worse in what is called a flare-up. A person unsure what to do can contact their GP or NHS 111 for advice, and 999 is for emergencies. NHS 111 can advise when it is unclear how serious a flare-up is.

A GP can look into new or ongoing breathing problems, because both conditions are diagnosed using symptoms, an examination and lung function tests.

What helps people living with either condition?

People with asthma are offered regular asthma reviews, where things such as flu vaccination can be discussed. For people with COPD who smoke, the NHS says stopping smoking is the most important step.

The NHS encourages people with COPD to have the yearly flu jab and a one-off pneumococcal vaccination, and for asthma it advises vaccinations such as the flu vaccine because viruses such as flu can make asthma symptoms worse. Flu jabs can be discussed at an asthma review.

What else do the sources say?

Pulmonary rehabilitation is a programme of exercise and education that can improve how far someone can exercise before becoming breathless. COPD can also come from long-term exposure to harmful fumes or dust, and rarely from a genetic problem that makes the lungs more vulnerable. Having eczema or hay fever, being born prematurely, or growing up around air pollution or cigarette smoke are linked with asthma. Asthma can have normal breathing test results at the time of the test, so one normal result does not always rule it out. NICE says COPD is suspected from symptoms and signs and supported by spirometry, which is also used again if the diagnosis is reconsidered. Flu jabs are given at a GP surgery or a taking-part pharmacy.