Peak Flow Meters

A peak flow meter is a hand-held device that shows how well you are breathing.

As part of your asthma action plan, you may use a peak flow meter at home to measure lung function. To use it, you take a deep breath and blow hard into a tube to find out how fast you can blow out. This gives you a peak flow number. You will need to find out your “personal best” peak flow number by recording the peak flow number daily for a few weeks until your asthma is under control. The highest number you get during that time is your personal best peak flow. Then you can compare future peak flow measurements to your personal best peak flow, and that will show if your asthma is staying under control or not.

Your doctor will tell you how and when to use your peak flow meter and how to use your medication based on the results. You may be asked to use your peak flow meter each morning to keep track of how well you are breathing.

The peak flow meter can also help warn of a possible asthma attack even before you notice symptoms. If your peak flow meter shows that your breathing is getting worse, you should follow your action plan. Take your quick relief or other medication as your doctor directed. Then you can use the peak flow meter to see how your airways are responding to the medication.

To get a rough indication of what your peak flow should be, various charts are available, such as this Peak Flow chart :

Causes of Occupational Asthma

Oddly enough, diesel fumes and many substances with a nasty smell don’t seem to cause asthma, even though there is important evidence that they can cause allergic reactions in your nose.

If your asthma is due to your work then it should be possible to remove the cause. The fact that you have asthma from work means that others could also get it, so the discovery could help a lot of people – including your employer.

If the asthma is discovered early, then your work environment can be improved, and the asthma treated, the result of which is usually a complete cure.

But if the occupational asthma is discovered after years of working with the offending materials, then it should get better when you no longer have breathe it in all day, but you are very likely to be left with permanent asthma, and this may be mild or severe asthma.

It is important to remember that asthma is so common that most people with asthma in a workplace have it for the same reasons as everybody else, and not because of their job.

This makes it hard to determine and discover the few people who really do have occupational asthma.

If you think that you have become affected by occupational asthma, then consult an expert on ‘Occupational Asthma’, or an allergist, as soon as possible.

Occupational Asthma

Some jobs can actually cause asthma. Asthma caused by dust or fumes at work is called occupational asthma.

All jobs which cause asthma involve some kind of dust, vapour or other fumes, although often the amount you breathe in is so small that people don’t expect any trouble.

The good news is that if your job is the cause of your asthma, then your asthma will disappear when you stop breathing any of the dust or fumes which caused it, provided that you and your doctors have caught and treated it early enough.

The bad news is that the longer you carry on with work which causes asthma, the more likely you are to carry on having permanent asthma even if you stop the work and completely avoid the dust, vapour or fumes.

Sadly, many people carry on working because no-one has noticed the connection with work, or because it seems impossible to leave or change jobs. In such cases, the penalty for your health may be very severe.

However, finding out for sure is vitally important for you. And, it might be vitally important for others as well.

Usually when a job is the reason for someone’s asthma, there are other people with asthma for the same reason at the same workplace and in the same industry and that no-one has noticed the connection in them.

Should You Avoid Exercise ?

People with asthma should definitely exercise. Enjoyable exercise is even more important for asthma sufferers than for other people.

Often in the past, children with asthma were asked to sit on the sidelines whilst their classmates played games and did sports. This is completely wrong if there is any reasonable way in which the child can be made fit enough to take part.

What is true for children is also true for adults.

Asthma attacks are hard work. One of the dangers in an asthma attack is fatigue, which may make you weaken in your fight to breathe. Strong breathing muscles are important to avoiding fatigue, and the way to get strong breathing muscles is to exercise.

So, far from being prevented from getting exercise, people with asthma should take as much suitable exercise as they can enjoyably manage.

With the right help, advice, training, treatment, and self-discipline the problems can usually be overcome.

Asthma and Types of Exercise

Some types of exercise are worse than others. For example, if you do different types of exercise that you use the same amount of oxygen, then some will cause more wheeziness or chest tightness than others.

Running outdoors is usually worse than swimming. In fact, swimming is one of the best forms of exercise for people with asthma because it usually causes the least amount of chest tightness.

Also, if the air you breathe during exercise is cold and dry, then the asthma will be worse. If it is warm and moist, the asthma will be less bad. This explains why swimming usually causes less asthma than outdoor running.

Increased breathing during exercise causes cooling and drying of the lining of the air passages and this is usually necessary for someone to get exercise-induced asthma. This explains why warm moist air protects against exercise-induced asthma. At this stage it is not understood why the drying and cooling of the airway linings causes the asthma episode.

Some people get worsening of their asthma from the chlorine fumes from swimming baths. This is another factor which can affect the result, and for such people swimming in a chlorinated pool is much worse than running.

Exercise-Induced Asthma

Asthma is a chronic lung condition that is characterized by difficulty in breathing. People with asthma have extra sensitive or hyper-responsive airways. During an asthma attack, the airways become irritated and react by narrowing and constructing, causing increased resistance to airflow, and obstructing the flow of the air passages to and from the lungs.

A few people seem to get asthma attacks only when they run or take other exercise.

In the past, doctors thought this was a different form of asthma. However, it is now known that it is very common for people with asthma to have asthma attacks during exercise.

This “exercise-induced asthma” is especially a problem for young people. In fact doctors used to puzzle over why children got exercise-induced asthma and why adults did not. Eventually research discovered the obvious reason : most adults do exercise as much as children.

Doctors now believe that people who get asthma attacks only when they exercise have asthma which is too mild to show up most of the time, needing the extra provocation from faster breathing to bring it out.

If the air you breathe during exercise is cold and dry, then the asthma will be worse. If it is warm and moist, the asthma will be less bad. This explains why swimming usually causes less asthma than outdoor running.

Asthma: Which Drugs and Medicines Safe For Use In Pregnancy ?

Here is a little about the main medicines used in asthma.


o Steroid Inhalers based on Becotide (beclomethasone dipropionate, now a common drug under all sorts of other names too) and Pulmicort (budesonide).
These steroids have been used for decades and on a massive scale, including a vast amount of use by women who were pregnant. There have been no evidence of harmful effects. In fact, in small doses these steroids are thought to offer additional protection to the baby from lack of oxygen.

o Cromoglycate (Intal, Lomudal, Cromolyn etc.) and Nedocromil (Tilade, Tilarin, etc.)
These asthma preventers are not steroids, but their safety record is very good indeed. No harmful effects on unborn babies have been recorded even though they have been in widespread use since 1968. They are still excellent medicines for people in whom they prove sufficient.

o Theophylline (many trade names)
Unlike inhaled drugs, theophylline is taken by mouth, usually as tablets, and, unlike the inhaled steroids, it is not broken down slowly by the liver. Despite widespread use, no harmful effects on unborn children have been described.

Relievers (bronchodilators)

Asthma and Pregnancy

The first question most women on medication ask when they are expecting a baby, is “Will this medicine harm my baby ?”

The good news is that all the common allergy and asthma medicines are known to be very safe during pregnancy. So, pregnant women should be able to enjoy an asthma and allergy free pregnancy.

In fact, asthma control is especially important when for pregnant women.

With newer drugs and medicines there is often no formal information about safety in pregnancy, because women who are or might become pregnant are not allowed to take part in the safety tests during the testing of the drugs or medicines for fear of harming the baby (and facing massive lawsuits as a result). No drug manufacturer wants to take the least risk with unborn babies.

However, older asthma treatment medicines exist, and these have been used for many decades, and long before the thalidomide catastrophe taught us that unborn babies are especially at risk. Many of these older asthma treatments have been used during pregnancy for decades, and are known to be safe in pregnancy.

In the case of newer medicines you should avoid them in pregnancy if possible, just in case. But there is a wide selection of older alternatives that are safe for use during pregnancy.