---- — DEAR DOCTOR K: I have asthma. Lately my symptoms have been worse at night. Why is that?
DEAR READER: I put many questions to what I call the “grandmother test.” My mother’s mother did not have much education, but she was smart and had great common sense. Her answer to your question would have been: “There’s something in your bedroom that’s irritating your lungs.” That’s what I think, too.
As you know, asthma is a long-term lung condition in which air passages narrow and become inflamed. This leads to breathing difficulties and wheezing.
The things in your bedroom that are most likely to trigger attacks of asthma are dust mites, mold or animal dander.
Dust mites are tiny, barely visible insects that live in our homes and feed on flakes of our skin. When you sleep, the oldest outer layer of your skin tends to come off when it rubs against the sheets. The dust mites love that. These little critters are built of substances that irritate the air passages in our lungs.
The same is true of mold. There is some mold in every home. Since mold likes damp places, there’s likely to be more mold in bathrooms, basements and poorly ventilated areas of the house. Molds are a type of fungi. Individually, molds are invisible, but when millions of them grow on something, like an overripe piece of fruit, you can see them.
Cats, dogs and other animals shed their skin and hair (their dander) just as we do. Animal dander contains substances that can irritate the air passages in the lungs.
You can help control these allergens:
— Clean and vacuum your bedroom frequently.
— Wash your bedding frequently in hot water.
— Remove carpets and heavy draperies from sleeping areas.
— Keep pets out of your bedroom and bathe them regularly.
Asthma sufferers can also be quite sensitive to environmental conditions. Your asthma may be reacting to air that is too hot, too cold, too moist or too dry. Experiment with adjusting the temperature and humidity in your bedroom and see what works best for your asthma.
Another possibility is that your controller medicine is wearing off too quickly. A controller medicine, such as an inhaled corticosteroid, helps prevent asthma symptoms. Ask your doctor if you need to increase your dose, or take a dose before you go to bed.
Many people find that lying down makes them more uncomfortable, although the asthma itself isn’t worse. Try propping yourself up rather than lying flat in bed.
Finally, gastroesophageal reflux (GERD) may be causing your symptoms to worsen at night. A small amount of stomach acid can come back up your esophagus and slide into your upper airways, irritating them. Try propping up the head of your bed, or ask your doctor about over-the-counter and prescription medications that can help control GERD.
I’ll bet that one of these suggestions will help you -- and prove that my grandmother was right!
(Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.)