Dry airways become irritated and swollen, which worsens asthma symptoms. Cold air also causes your airways to produce a substance called histamine, which is the same chemical your body makes during an allergy attack. Histamine triggers wheezing and other asthma symptoms.
When you work out, your body needs more oxygen, so your breathing speeds up. Often, you’ll breathe through your mouth to take in more air. While your nose has blood vessels that warm and humidify the air before it reaches your lungs, air that travels directly through your mouth remains cold and dry. This is just one way that exercising outdoors in cold weather increases your likelihood of having an asthma attack.
Colds, flu, and other respiratory infections tend to circulate during the winter months. These infections are also known to set off asthma symptoms.
Cold air can also drive you indoors, where dust, mold, and pet dander flourish. These allergens set off asthma symptoms in some people.
Make sure your asthma is under control before winter arrives. See your doctor to develop an asthma action plan, and then take the medicines your doctor prescribed. You may take medicine every day or just when you need it.
Long-term controller medicinesare drugs you take every day to manage your asthma symptoms. They include inhaled corticosteroids, long-acting beta-agonists, and leukotriene modifiers.
Quick-relief medicines are medicines that you only take when you need them, such as before exercising in the cold. Short-acting bronchodilators and anticholinergics are examples of these drugs.
Here are a few tips:
Drink extra fluids in the winter. This can keep the mucus in your lungs thinner and easier for your body to remove.
Try to avoid anyone who appears to be sick.
Get your flu vaccine early in the fall.
Vacuum and dust your home often to remove indoor allergens.
Wash your sheets and blankets every week in hot water to get rid of dust mites.
For most people, if their asthma is managed properly and under control then the weather should not have much of an effect, however for others extreme weather conditions can bring on symptoms and organisations suggest extra thought and care is taken before heading out in it.
Changes in temperature of the air within your airways can cause inflammation, for most this is not a problem as the nose controls humidity and temperature. With people who suffer from asthma, they tend to breathe more through the mouth and irritants, pollutants and pollen are more of a factor and many already have inflammed airways. The more severe the asthma, the more likely it is that the weather will affect them.
Common weather triggers include:
• Cold air can cause constriction of airways.
• Wind and rain-Rainfall can increase and stir up mould spores, and wind can blow around pollen and mould.
• Heat-increased ozone from smog, exhaust fumes, and pollutants tend to be higher. Dry hot air can also trigger asthma.
• Lightning-Thunderstorms, which can generate ozone, are now thought of as an asthma trigger.
• Air pressure fluctuations-Barometric pressure can trigger sinus episodes and sinusitis is a common asthma trigger.
Cold Winter Air:
75% of asthma sufferers say that cold air can trigger asthmatic symptoms. The advice is to ensure that you are managing your asthma and taking any prescribed medication. Just as important is to be prepared. Check the forecast and make sure you carry your inhaler with you, wrap up warm and dry and wrap a scarf around your nose and mouth and try breathing more through your nose and it will help to dehumidify and warm the air up.
Remember that the difference between inside and outside temperature can be a factor so even going in and out of heated shops, or going from a nightclub or pub out into the cold air are all times when you need to look after yourself.
Exercise is very beneficial for people with asthma as it can help improve lung function and improve fitness but over three quarters of people with asthma have told Asthma UK that exercise in colder weather is a trigger for their condition. This is mainly due to the fact that during aerobic exercise you would inhale more of the cold air, breathing it in through your mouth (which means that it is not warmed or moistened by your nose) and breathe it more deeply into your lungs.
There are many things you can do to maintain your exercise regime but avoid the triggers.
• Exercising indoors or at a gym or gym classes instead of venturing outside.
• Warm up and warm down for 10-15 mins before and after outside exercise.
• Dress appropriately with a scarf around your throat and nose.
• If symptoms begin stop exercising immediately, take your inhaler and wait until you feel better before you resume.
• Consider more moderate exercise that will reduce the need for such deep breaths like a power walk instead of a run or a more gentle bike ride.
When it is cold many avoid going outside to try and avoid the triggers, however spending more time indoors exposes you to more triggers within the home such as pet hair, smoke, dust mites, fireplaces etc. Many sufferers prepare themselves for this and from being out in the cold by having a back-up home oxygen supply to use when the cold weather has triggered off a bad asthma attack.
More recently it has become apparent that thunderstorms can trigger serious asthma attacks, especially children and young adults, with large numbers of people needing to go to A&E.
It is not fully understood why this happens, but it is thought during a thunderstorm, the windy conditions cause high levels of pollen and mould spores to be swept up high into the air where the moisture breaks them into much smaller pieces. As the pollen and mould particles then settle back down, these smaller pieces of pollen and mould can be breathed into the smaller airways of the lungs where they irritate the airway and trigger asthma symptoms.
Not all thunderstorms trigger asthma, it seems to depend upon the time of year, the humidity, wind, air pressure and whether ozone levels are high.
The advice is to be aware of weather forecasts, try to avoid being caught outside in them and make sure you carry your inhaler.
References: http://www.everydayhealth.com/asthma and http://www.asthma.org.uk