Asthma.net asked our experts, “Is there a connection between dehydration and asthma?” Here are some of the expert responses:
Response from Lyn Harper, MPA, BSRT, RRT:
Since the adult human body is made up of about 60% water, it makes sense that water would play a key role in our basic health – even that of our lungs and pulmonary system. Hydration certainly plays an important role in the ability to thin and clear secretions. As any asthmatic knows, there are episodes of inflammation in which the airways become increasingly filled with mucus. To mobilize and rid the airways of those secretions a person must remain well hydrated.
There have been a number of studies done, particularly in Europe, that show histamine is produced at a greater rate when a person is dehydrated.3 For those that suffer from any kind of asthma, but allergic asthma in particular, that would be an important component. If histamine is being produced, allergies are triggered, and therefore asthma is aggravated. Another good reason to stay hydrated
Response from Lorene Alba, AE-C:
I have read many articles recently on blogs and websites claiming dehydration is the real reason people have asthma, and/or promises that your asthma can be “cured” if you just drink enough water. Of course, there is no cure for asthma, but a good asthma and general health management plan should include drinking plenty of water. Increasing your water intake can help you maintain a healthy weight and even improve your mood. When you are dehydrated the lining of your airways and sinuses become dry. This dryness can result in asthma or other symptoms such as headache and nausea. Hydrating is especially important for those with asthma caused by exercise. When you exercise you tend to breathe through your mouth, causing dry air to enter your lungs. This dry air can contain triggers such as pollen or pollution, causing asthma symptoms. Keep your airways (and body) hydrated by drinking plenty of water each day and breathing your nose, which helps moisten and filter the air before it gets into your lungs.
Response from Leon C. Lebowitz, BA, RRT:
The standard hallmark of asthma is hypersensitivity of the airways. Asthma is characterized by chronic airway inflammation and episodic airway obstruction. For people who have asthma, their airways can be sensitive to ‘irritants’ which may not bother or affect other people. These irritants are referred to as ‘triggers’. Asthma triggers can vary from person to person. Some people can be affected by just a few
while others may react to many different ones.1
If you have asthma, it is important to keep track of, and be aware of the causes or triggers that are known to provoke your own asthma. Because the symptoms do not always occur right after exposure, this may take a bit of detective work. Delayed asthma episodes may occur depending on the type of trigger and how sensitive a person is to it.1 In general, these triggers are small enough to be inhaled and make it to the airways where they can set off a sequence of events that lead to asthma symptoms. Symptoms typically include wheezing, coughing, shortness of breath, and chest tightness. Clearly, when these symptoms start unexpectedly and get increasingly worse, an asthma attack may follow.5
The most common inhaled asthma triggers include dust mites, pet dander, mold, pollen, air pollution, cigarette smoke, and cold or humid air, to name just a few.5
A search of the medical literature does not show any extensive evidence that dehydration itself is connected to asthma as a trigger. It is well known, however, that asthmatics are more sensitive to dehydration then non-asthmatics. As well, dehydration can often times be associated with a side effect of asthma and it’s medications.
Keeping a good water balance is a good idea for asthmatics as many components of asthma attacks and treatment focus on a proper water balance for the body. Some clinical experts even recommend sufficient hydration as an adjunct to asthma therapy.
You can be your own best advocate and caretaker. The more you know about your own asthma condition, the better able you will be to avoid triggers and acute exacerbations.
Response from John Botrell, RRT:
A few years ago I was having trouble with my asthma during the summer. I discussed this with my doctor and he suggested something that made me roll my eyes. He said, “I think you are dehydrated. I think you need to drink more water.” After a few days of drinking 8-10 glasses of water, I was breathing easier. This made me do some research, and I found quite a bit of material. One theory postulated was that when the respiratory mucous membrane becomes dry, this causes the release of inflammatory markers like histamine, resulting in the allergy and asthma responses.4 So, therefore, anything that causes dehydration can also cause asthma. The best logical solution here is to make sure you stay hydrated, and most experts recommend 8-10 cups of water every day.
Response from Theresa Cannizzarro, Respiratory Therapist:
Staying hydrated is very important for everyone, including asthmatics. Being dehydrated can definitely cause one’s asthma to act up. When your body is dehydrated, it can cause your electrolytes to become out of balance, especially your potassium and sodium levels. If you are dehydrated, the body will produce histamine. It is known that asthmatics have excessive levels of histamine in their lung tissue which can cause bronchoconstriction and increased mucus buildup in the lungs.2