context: If your doctor has told you that you have severe asthma, one of the most important parts of treatment is to find out what all of your triggers are so you can avoid them. The same things that prompt a regular asthma attack can cause a severe one. Common triggers include: Allergies. If you're allergic to something, it can launch an asthma attack. Common allergens include pollen, cockroach droppings, mold, grasses, weeds, animals, and dust mites. If you have asthma that's hard to control, you should see an allergist to find out if you have allergies. Treating your allergies with medication and avoiding your triggers can help lower the odds you'll have a severe asthma attack. Tobacco smoke. Even if you don't smoke, being in a space where someone else has smoked (even if it was a while ago) can cause an asthma attack. Air pollution, chemical fumes, or other substances in the air. Even something like strong household cleaners and perfume could be a trigger for some people. Illness. A cold or upper respiratory infection, the flu, and sinusitis (inflammation or swelling of your sinuses) are common culprits. Acid reflux, with or without heartburn, can also be a cause. Some medications. These include aspirin and other nonsteroidal anti-inflammatory drugs ( NSAIDs) such as ibuprofen and naproxen. Some beta-blockers -- which treat heart disease, high blood pressure, migraine, and glaucoma -- are also on the list. If you have severe asthma, talk to your doctor about any medication you're considering taking, even if it's an over-the-counter medication. Exercise. You should still work out. Staying fit is important for everyone. But if you have severe asthma and you're not active now, talk to your doctor first about how to track your breathing and choose the right activities. When it's winter, avoid exercising outdoors in extremely cold weather because the exposure could trigger asthma. The weather (sometimes). Very cold or dry weather, or changes in the weather, can cause an attack. Stress and anxiety. If you're upset, your breathing can change. This can bring on an attack. Depression and chronic stress are linked to asthma. If you've been feeling down, anxious, or stressed out, tell your doctor. It can be tough to identify them all, and they can change. For example, you might not have been bothered by tree pollen when you were a child, only to have a problem with it as an adult. Even when you know your triggers, you might have a hard time avoiding them in certain situations. For example, you may notice that your workplace is cleaned with a cleaning product that bothers your lungs. That's why it's so important to work closely with the doctor who treats your asthma. She can help you think of strategies to avoid triggers, or at least cut down on the amount of time you spend near them. She can also make sure you have the right medication when an asthma attack does strike. Warning signs of a potential asthma attack include: Needing more rescue inhaler medication (such as albuterol). A cough that gets worse. Feeling like you can't breathe or like someone's sitting on your chest. Waking up at night feeling like you can't breathe. Not being able to be active or exercise without getting winded or wheezing. You should take your asthma rescue inhaler medication as soon as you start to feel an attack come on. If it doesn't seem to work and you feel like you still can't breathe, call 911 so you can get to an emergency room right away. If you have a steroid medicine at home (such as prednisone), you can take it on your way to the ER.