Asthma: symptoms, triggers, tests and management, a review

Asthma is a common condition that affects breathing. For most people, asthma has only a small impact on daily life when treatment works well ^[1]. This article explains what asthma is, what sets it off, how it is diagnosed and how it is managed, using information from the NHS, MedlinePlus and the US CDC.

1. Introduction

Asthma is a long-term condition that affects the airways, which are the tubes that carry air into and out of the lungs. In asthma the airways become swollen and narrow, which makes breathing harder ^{[1, 2]}. The NHS notes that asthma usually starts in childhood but can begin at any age ^[1].

The CDC explains that a person with asthma has the condition all the time, but attacks happen only when something irritates the lungs ^[3]. An asthma attack is a flare-up of severe symptoms that can make breathing very difficult and can be life-threatening ^{[1, 2]}.

2. Signs and symptoms

Symptoms can be mild or severe, and they tend to come and go. Common signs are ^{[1, 2, 3]}:

• Wheezing, which is a whistling sound when breathing out
• Coughing, often worse at night or in the early morning
• Shortness of breath
• Chest tightness

During an attack these symptoms get much worse, and they may begin gradually or suddenly ^[2].

3. Causes, triggers and risk factors

The exact cause of asthma is not fully understood. MedlinePlus says that genes and the environment both seem to play a part ^[2]. An attack is set off by a trigger, and triggers differ from person to person and can change over time ^[2].

Common triggers

• Allergens such as pollen, dust mites, mould, and pet fur or dander ^{[1, 2]}
• Cold air, tobacco smoke and outdoor air pollution ^{[1, 2]}
• Colds, flu and other infections ^{[1, 2]}
• Exercise, especially in dry air ^{[1, 2]}
• Household chemicals, and in some people certain medicines ^[2]
• Chemicals or dust breathed in at work, which can cause occupational asthma ^[2]

The NHS notes that some common pain-relief medicines and some heart medicines can trigger symptoms in certain people, so check with a pharmacist or doctor before taking a new medicine ^[1].

Who is more likely to develop asthma

Risk is higher in people with other allergic conditions such as eczema or hay fever, and in people with a family history of asthma or allergies ^{[1, 2]}. Other risk factors include being born early or very small, breathing in smoke or pollution in early childhood, frequent chest infections in childhood, and being overweight ^{[1, 2]}.

4. Diagnosis and tests

Diagnosis can take time because symptoms vary and other conditions can cause similar problems ^[1]. The NHS says a doctor or nurse will ask about your symptoms and listen to your chest. A simple breathing test may be done, and sometimes a blood test ^[1].

MedlinePlus lists other tests that may be used ^[2]:

• Spirometry, a breathing test that checks how well your lungs work
• Peak flow, which measures how fast you can blow air out. You may be given a small hand-held peak flow meter to track this at home over several weeks ^[1].
• A test of exhaled nitric oxide, which can show inflammation (swelling) in the airways
• Allergy skin or blood tests when allergies are suspected

The CDC adds that doctors may ask about chest tightness, wheezing, coughing a lot (especially at night) and colds that last longer than 10 days. It notes that asthma is especially hard to identify in children under 5 ^[3].

5. Treatment and management

Care is planned with your doctor, who decides which treatment is right for you. The main parts are described below ^{[1, 2, 3]}.

• Avoiding triggers. Keeping smoke out of the home and car, and reducing allergens where possible, helps.
• Quick-relief (reliever) medicine. This is usually an inhaler that you carry at all times. It eases symptoms when they occur.
• Controller (preventer) medicine. This is taken regularly to calm swelling in the airways and lower the number and severity of attacks ^{[2, 3]}.
• Stronger treatments. If inhalers are not enough, the care team may add other medicines. For severe asthma that does not respond, injected treatments or, in some adults, a heat-based procedure on the airways may be considered, and the risks should be discussed first ^{[1, 2]}.

Using your inhaler the right way matters. A doctor, nurse or pharmacist can show you how ^[1]. The NHS says your care team will record your plan in a personal asthma action plan, and that you should have a check-up at least once a year ^[1]. The CDC advises that if you need your reliever more and more, you should see your doctor to find out whether you need a different medicine ^[3].

6. Prevention and self-care

There are things you can do to help prevent symptoms and reduce the risk of attacks. The NHS suggests ^[1]:

• Carry your inhaler with you and use it as your care team advised.
• Avoid known triggers where possible, such as smoke, pollution, pollen and animals.
• Stay active, and ask for advice on safe exercise if it brings on symptoms.
• Keep to a healthy weight.
• Stop smoking, and ask for support if you need it.
• Keep up with vaccinations, including the flu vaccine, because infections can make asthma worse.

7. Special groups

Children often get asthma first, and for some it eases by the teenage years or adulthood ^[1]. Asthma is hard to spot in children under 5 ^[3]. People who are pregnant should tell their doctor or midwife about their asthma, because good control is important for both mother and baby ^[1]. Breathing in certain chemicals or dusts at work can cause asthma ^{[1, 2]}.

8. When to see a doctor

See a doctor if you or your child has asthma symptoms, if treatment is not helping, if you need your reliever more often, or if symptoms wake you at night or disrupt daily life ^{[1, 3]}. The NHS advises a check-up within 2 days after recovering from an attack, to review treatment and lower the chance of another ^[1].

Get emergency help if symptoms get worse, if your reliever does not help as your plan says, or if you do not have your inhaler. While waiting, sit upright and try to stay calm. Do not drive yourself to hospital ^[1].

In an emergency, call your local emergency number (112 in India, 911 in the United States).

9. Conclusion

Asthma is a common long-term condition in which the airways swell and narrow. It is often a life-long condition, but when it is well treated most people should not have problems with symptoms. Knowing your triggers, using medicines as advised, having regular reviews and knowing the signs of a severe attack are the most useful steps.