Asthma or COPD: what is the difference?

“Do I have asthma or COPD?” is one of the most common questions from people with a cough and breathlessness. It is a reasonable question, because the symptoms are similar. But the two are different conditions, and the answer cannot be given from symptoms alone.

Shared symptoms

WHO says asthma and COPD share symptoms, namely cough, wheezing and breathlessness, and a person may have both. So if you do not know which one you have, that is not surprising. Listening to the chest and asking a few questions is not enough to be certain either. A doctor usually asks for a breathing test as well.

What is asthma like?

• Asthma is a long-term condition of the airways. The CDC says that in an attack the wall of the airway swells and narrows, and mucus blocks the air. Asthma is always there, but an attack happens when something irritates the lungs.
• Symptoms come and go. The NHS says symptoms often vary over time. The CDC counts a cough at night or early in the morning among the symptoms of asthma, and the NHS counts exercise among the triggers.
• It can occur at any age. The CDC says it is one of the most common long-term conditions of childhood, but adults get it too.
• Triggers such as pollen, dust, smoke, cold air, exercise and viral infections make symptoms worse (NHS and CDC).
• It can be controlled but not cured. The NHS and WHO say there is currently no cure for asthma, but there are many treatments. WHO says inhalers can control the condition and let a person live a normal, active life.

What is COPD like?

• COPD is the name for a group of conditions. The NHS and WHO count emphysema (damage to the air sacs) and chronic bronchitis (long-lasting inflammation of the airways with a cough that brings up phlegm) as part of it.
• It mostly appears in middle age and later. The NHS says it is mostly seen in middle-aged and older people who smoke. WHO says symptoms usually appear from middle age onwards.
• The main cause is long exposure to smoke and substances that damage the lungs. WHO regards smoking and air pollution as the most common causes, and also lists smoke from wood and charcoal in the home, dust and chemicals at work and second-hand smoke. The NHS reminds us that COPD is sometimes found in someone who has never smoked. So there is no place for blame.
• It is progressive. NHLBI says symptoms start slowly and get worse over time. The NHS says the lung damage in COPD is permanent and the condition cannot be cured or reversed. Treatment can slow its progress, and many people live normal lives with treatment.
• The most common symptoms are breathlessness (especially with activity), a long-lasting cough with phlegm, frequent chest infections and wheezing (NHS). The NHS says many people do not know they have COPD and sometimes call a cough with phlegm a “smoker’s cough” and ignore it.

The main differences at a glance

This table is a general pattern, not a tool for diagnosing yourself.

Feature	Asthma	COPD
Symptoms	Come and go, often with a trigger and at night or early morning	Usually more constant and gradually worse
Start	Often childhood, but any age	Usually middle age and later
What makes it worse	Triggers such as pollen, dust, smoke, cold air, exercise, viral infection	Chest infection, continued exposure to smoke
Known causes	The exact cause is not always clear	Smoking, air pollution, long exposure to smoke and dust
Course	Can be controlled with treatment	Lung damage is permanent, but treatment slows progress

This table is summarised from the sources above and has many exceptions. For example, a child may have a history of asthma and get COPD as an adult (WHO counts childhood asthma among the risk factors for COPD).

How does a doctor tell them apart?

1. Questions and examination. The NHS says that for COPD they ask about symptoms, smoking history and family history of lung disease, and listen to the chest. For asthma, about symptoms, triggers and allergy history.
2. Spirometry. WHO and the NHS regard it as necessary to confirm COPD. In asthma it (or a peak flow meter) is also used (NHLBI). Sometimes the results are compared before and after an airway-opening medicine (NHLBI, NHS). Read about the test in the guide “Lung tests and imaging”.
3. Other tests. For COPD the NHS names an X-ray, blood tests and sometimes a CT scan, a phlegm sample or an oxygen check. For asthma NHLBI mentions allergy tests, FeNO, blood tests and sometimes a challenge test. According to the NHS, a peak flow meter can also help rule out asthma in COPD.

The NHS stresses that diagnosing asthma can take time because symptoms change over time. Sometimes the doctor starts with a trial of medicine and watches the response.

If you have both

WHO says a person may have both. In that case the doctor sets the plan based on your situation. You should not assume which one it is and change your inhaler on that basis.

Treatment: the aim is control

In both conditions the aim of treatment is to control symptoms and reduce attacks.

• Inhalers are the basis of treatment. WHO regards a steroid inhaler to prevent attacks as the main treatment in asthma, and an airway-opening inhaler in COPD. The NHS says that in COPD treatment usually starts with a short-acting inhaler, and sometimes a steroid inhaler is given combined with a long-acting medicine. Your doctor sets the type and schedule.
• Do not stop your controller inhaler because you feel better. The NHS says it must be used even without symptoms. Do not reduce or stop steroid tablets on your own either. Details are in the guide “Asthma and COPD inhalers”.
• Stopping smoke exposure. The NHS regards stopping smoking as the most effective way to prevent COPD getting worse, and says even people with more advanced disease benefit. You can ask your doctor for help with stopping.
• Pulmonary rehabilitation (in COPD). The NHS describes it as a programme of exercise and education that can raise the amount of activity you can do without breathlessness.
• Vaccines and a written plan. Ask your doctor which vaccines suit you (WHO counts vaccination among the things that help COPD). In asthma, bring your written plan with you (NHS).
• Infection and attacks. In COPD only a doctor prescribes antibiotics, and the NHS ties them to signs of a chest infection such as more breathlessness, more cough or a change in the colour and thickness of phlegm.

When should you be seen sooner?

• The NHS says that if you have breathing symptoms that persist, especially if you are over 35 and you smoke or used to smoke, make an appointment and do not ignore them. Starting treatment early, before much lung damage, is better.
• If your breathing suddenly gets worse, your reliever inhaler does not work or your lips turn blue, do not wait for an appointment. See the guide “When to call urgently” and call 115 (Iran’s emergency number).

A few final points

• A cough or breathlessness is not always asthma or COPD. For cough the NHS also lists reflux, allergy, infection and mucus dripping from the back of the nose. That is why assessment is needed.
• If you already have a diagnosis and are not sure it is right, raise it with your doctor and bring your earlier reports and spirometry.
• None of this is a reason to be afraid. Both can be controlled with a suitable plan, and starting sooner is better.