What Are the Causes of Asthma?

Although asthma can happen to anyone, there are some risk factors that make it more likely that certain people will suffer from the condition.

Gender can play a part in the likelihood of developing asthma. Boys are more likely to develop childhood asthma than girls. But by the age of 35, more women than men have asthma.

Those with atopic conditions such as eczema or atopic dermatitis can be more susceptible to asthma. People with allergies to certain things, for example pet hair, dust mites, moulds and fungi, are also more likely to suffer from asthma and these factors can also make asthma symptoms worse.

It is also thought that asthma is more common in overweight people. Obesity is associated with a higher incidence of asthma and poor asthma control, and losing weight is associated with a reduction in the severity of asthma symptoms.

There are numerous other factors which are believed to increase your risk of developing asthma, such as:

  • Premature birth / low weight births
  • Exposure to smoking when a child
  • Childhood history of bronchiolitis
  • Occupational asthma

Is Asthma Hereditary?

Genetics also have a role in whether a person develops asthma or not. If you have a family history of asthma, you are more likely to have asthma than someone who doesn’t have a parent with the condition.

What Triggers it?

While there are risk factors associated with asthma that you can’t change, such as genetics or your gender, there are some things that you can do something about. There are a number of ‘asthma triggers’, which are things that set off the symptoms of asthma or make existing symptoms worse. There may be a number of triggers that irritate the airways and cause asthma and it can be tricky to work out exactly what is causing the symptoms.

In many cases, asthma is triggered by a substance you are allergic to, such as:

  • house dust mites
  • moulds and fungi
  • pollen
  • the dander in animal hair
  • environmental pollution such as car exhaust fumes
  • smoking or breathing in secondhand cigarette smoke
  • alcohol
  • recreational drugs
  • certain medications
  • certain foods

Asthma can also be triggered by:

  • exercise
  • anxiety and stress
  • laughter
  • respiratory tract infections such as colds and flu
  • hormones (in women)
  • changes in weather

Sometimes it will be obvious that something causes your asthma symptoms - for example if you stroke a cat or dog and then shortly afterwards your symptoms start. Other triggers are harder to identify, for example, grass pollen may bring on your asthma, but as it’s invisible you might not make the connection. There may also be more than one trigger involved in setting off your asthma, and sometimes the symptoms might not show up until a while after you’ve come into contact with the trigger.

A good tip when trying to pinpoint what is causing asthma is to keep a diary of where you were and what you were doing when you noticed your symptoms begin to flare up so that you can spot if certain things are present every time.

Once you have identified what causes your symptoms it is easier to try to avoid those things and reduce the risk of setting off asthma symptoms or making them worse.

What Symptoms Does it Cause?

The symptoms of asthma range from mild to severe (around 5% of asthma sufferers are diagnosed with severe asthma).

The symptoms of asthma include:

  • wheezing (a whistling sound that is worse when exhaling)
  • coughing
  • breathlessness and difficulty breathing
  • tightness in the chest

Asthma symptoms can be worse at night and when you first wake up in the morning. They can also start or worsen when exposed to certain triggers.

It is very important that even those with mild asthma get treated and agree an asthma management plan with their doctor, as all asthma symptoms can be very dangerous and even fatal if left untreated.

What causes Asthma Attacks?

If you notice your asthma symptoms getting much worse, this could be an asthma attack and it is a serious condition that needs immediate medical attention.

Asthma attacks, also known as acute asthma exacerbation, can come on very quickly and very severely, or sometimes can develop in severity over the course of two or more days.

If you know the warning signs of an asthma attack, you will be able to recognise them early and act quickly to avoid the attack getting worse. You might find that your reliever inhaler (for example the blue Ventolin inhaler) doesn’t work as well as it usually does.

If you think you are having an asthma attack, you mustn’t ignore it and hope it will go away. Seek medical help immediately, and make sure that you have your asthma medication to hand. It is useful to have your doctor’s contact details memorised or easy to find at all times so that you can get help as quickly as possible if you have an attack - and if it is severe, call 999 or got to A+E.

The warning signs of a severe asthma attack include:

  • wheezing, tightness in the chest and coughing becoming severe
  • asthma symptoms becoming constant
  • you can’t speak because you can’t breathe well enough
  • difficulty sleeping or eating because you are too breathless
  • your reliever inhaler doesn’t work as well or doesn’t work at all to relieve symptoms
  • fast heartbeat
  • faster breathing
  • feeling sleepy or dizzy
  • lips and fingers turn blue

These symptoms are very serious and you must call 999 for an ambulance immediately.

Types of Asthma

Doctors differentiate between different types of asthma depending on what is causing the condition to flare up. This includes:

  • Allergic asthma - caused by a reaction to an allergen
  • Occupational asthma - caused by a reaction to an allergen or irritant at work
  • Exercise induced asthma - your airways narrow when you exercise
  • Cough-variant asthma - caused by an infection or exercise, the main symptom is a cough
  • Seasonal asthma - usually caused by allergens during certain times of the year (for example pollen in spring and summer)
  • Adult onset asthma - often caused by infections or exercise, might flare up when you get excited or are laughing, may be affected by hormonal changes

What causes adult onset asthma?

It is a common misconception that asthma always starts when you are still a child. This is incorrect - it is not unusual for adults to develop what is defined as adult or late onset asthma.

Unlike asthma in children, adult onset asthma is not usually caused by an allergic reaction but is more likely to be triggered by a respiratory infection or induced by exercise.

Asthma is considered late onset if you experience the symptoms for the first time when you are over 20 years of age.

What Causes Asthma at Night?

The symptoms of asthma can get worse at night. Night time asthma, also known as ‘nocturnal asthma’, can make sleeping very difficult for sufferers and can make them feel very tired and irritable during the day.

Night time asthma is a serious condition and it is very important to get diagnosed correctly so that you get the right treatment and develop an asthma management plan with your doctor to keep it under control.

It is not fully understood why asthma symptoms can get worse at night, but reasons include:

  • a drop in temperature in the airways due to breathing colder air at night, which can cause them to narrow and make breathing more difficult
  • exposure to triggers such as allergens in the bedroom (for example house dust mites)
  • lying down
  • sinusitis - where mucus in your nose drips down the back of the throat, triggering asthma symptoms when it reaches the sensitive airways
  • heartburn
  • hormone levels that peak or trough (lower) during the night

Taking a preventer inhaler such as Pulmicort, Symbicort or Seretide can help to reduce the inflammation that contributes to the symptoms of night time asthma and help you breathe and sleep easier.

How can Asthma be Treated?

There is no cure for asthma, but there are a number of effective treatments available to relieve the symptoms and to help prevent them coming on and recurring. In combination with an asthma management plan agree with your doctor, asthma treatments can help you to effectively manage your condition.

Asthma medications are commonly taken daily with an inhaler. There are two types of asthma inhalers, reliever and preventer inhalers.

You may be prescribed a reliever inhaler which relieves the symptoms, such as wheezing. You take the inhaler when you feel the symptoms of asthma coming on, and the drug is delivered straight into your lungs to help you to breathe properly again. You may also be prescribed a preventer inhaler, which helps to control the symptoms of asthma before an attack happens.

Identifying the things that trigger your asthma and avoiding those as far as is possible is also an effective way of keeping asthma under control.