Spirometry with reversibility
You blow into a device before and after airway-opening medication. A clear improvement is one of the ways the diagnosis can be settled. A normal spirometry on the day does not rule asthma out.
Knowledge
Asthma in adults.
Asthma is common, treatable and often lived with for years before it is properly named. What asthma actually is. How the diagnosis is established with measurements rather than symptoms alone. What good control looks like.
What asthma is.
Asthma is a condition of the lower airways in which the lining is inflamed and the airways react more readily than they should. The reaction narrows the airway from three directions at once: the lining swells, mucus is produced, and the smooth muscle around the airway tightens. That is why the same person can breathe perfectly well one day and be short of breath the next.
The variability is the point. A cold, pollen, cold air, exercise, tobacco smoke, a pet or a period of stress can each tip the balance, and the pattern is different from person to person. Two things follow from that: the diagnosis cannot rest on how you feel on the day you are examined, and treatment is aimed at the underlying inflammation rather than at the individual bad day.
Symptoms
What it feels like.
Not everyone has every symptom, and some have only one. What points towards asthma is the pattern: symptoms that come and go, that are worse at night or in the early morning, and that are set off by something recognisable.
- Wheezing from the chest
- Tightness across the chest
- Cough, often dry, often at night or in the early morning
- Breathlessness that comes and goes
- Symptoms set off by exercise, cold air, colds, pollen, animals or smoke
- A period of weeks where a chest cold refuses to settle
How the diagnosis is established.
Symptoms alone are not enough. They overlap with several other conditions, and they are absent on a good day. The diagnosis therefore rests on a measurement showing that the airway obstruction is variable: that it can be brought on, or reversed, and that the change is large enough to count.
Bronchial provocation test
When spirometry alone does not settle the question, the airways are challenged gently and under control, so a tendency to react can be measured. The clinic offers mannitol, methacholine, EVH and a standardised exercise challenge on a cycle ergometer.
FeNO measurement
A simple breath test measuring nitric oxide in exhaled air (a marker of the eosinophilic, often allergic, airway inflammation seen in asthma). It helps confirm the diagnosis and guide treatment.
Allergy testing
A skin-prick test and, where relevant, a blood test map the allergens that matter for you. Allergy is not the cause in everyone, but where it is present, it changes what can be done about the triggers.
Some inhaled medication must be paused before the measurements, or the test will show the medicine rather than the asthma. Only pause if the clinic has asked you to. The pause times are listed on the lung function page.
Treatment
Treatment aims at the inflammation, not at the bad day.
Inhaled corticosteroid is the foundation. It works on the underlying inflammation, and it works only while it is being taken, which is why it is the part people most often stop too early, and the part that most often explains why the asthma came back. For some people the preventer and the reliever are combined in a single inhaler.
Short-acting reliever medication on its own is not a treatment. Needing it often is a sign that the underlying treatment should be adjusted, not that you should take more of it. Which inhaler, in what dose and in what combination is decided individually, and the inhaler technique is worth going through, because a large share of poor control is technique rather than dose.
Alongside the medication: what can be done about the triggers. For smokers, quitting is the single most important step. Allergen immunotherapy is relevant for some with airway allergy, and a blocked nose is an accompanying condition worth treating.
What good control looks like.
Well-controlled asthma is not a matter of luck. It has a description: no cough, wheeze or chest tightness in everyday life, no symptoms at night, no limitation of what you want to do, and rare need for reliever medication. If any of those is not true, something can usually be adjusted.
Where the asthma remains difficult despite correct treatment, the next step is not automatically more medicine. It is a systematic review: is the diagnosis right, is the inhaler technique right, is the medication actually being taken, is there an untreated nose, reflux, a laryngeal cause or a breathing pattern that keeps the symptoms going? Where biologic therapy is indicated, that is hospital medicine, and the referral goes on from here.
If your asthma gets worse
Contact your GP or the clinic if your reliever medication wears off sooner than usual or is needed every day, if the symptoms wake you at night, or if you cannot keep up your usual level of activity. Those are signs of a worsening, and that the treatment needs adjusting.
Contact your own GP during their opening hours. Outside your GP's opening hours: the 1813 medical helpline (the Capital Region of Denmark). For life-threatening symptoms, including severe breathlessness where you cannot speak in full sentences, or where the reliever medication is not helping: 112. The clinic is not an emergency service.
FAQ
Frequently asked questions about asthma.
Can asthma go away?
It can settle for long periods, and some people have no symptoms for years. The tendency for the airways to react usually remains, so it is better thought of as something that can be well controlled than as something that is cured. That is also why treatment is reviewed rather than simply stopped.
Can I exercise with asthma?
Yes. Well-controlled asthma is not a reason to train less, and physical activity is good for the lungs. If exercise itself sets off the symptoms, that is a specific pattern which can be measured and treated.
Do I have to take medication every day?
It depends on how much asthma you have. Some need preventer medication every day, others only as needed, but it works only while it is being taken. How much, and in what form, is decided individually and reviewed as the asthma changes. Never stop your preventer on your own.
Can I continue my asthma inhaler if I am pregnant?
As a rule, yes. Well-controlled asthma matters for both you and the baby, and most inhaled treatments are continued during pregnancy. Never stop your preventer medication on your own. Talk to us or to your GP, so the plan can be adjusted.
Is asthma medication allowed in competitive sport?
Ordinary inhaled treatment is largely permitted within set limits. A smaller number of medicines require an exemption. The binding answers lie with Anti Doping Danmark and the current WADA list.
Background and sources
Selected references behind this page.
- Global Initiative for Asthma (GINA). Global Strategy for Asthma Management and Prevention, 2026. ginasthma.org
- Price OJ, Walsted ES, Bonini M, et al. Diagnosis and management of allergy and respiratory disorders in sport: an EAACI task force position paper. Allergy 2022. DOI
Get your asthma properly assessed
The clinic assesses asthma with lung-function testing, FeNO measurement and, when needed, a provocation test matched to your situation. A referral from your GP is normally required; you can also be seen as a private or insurance patient. This page is general information and does not replace a medical assessment.