How do I know I have asthma and what can happen over time?

Diagnosis:

In order to determine if you have asthma, a visit to a healthcare provider (such as a doctor or a nurse practitioner) is the best way. While the internet is a wealth of information, one should never diagnose themselves based on things that haven't been confirmed by a healthcare professional. There are several ways a health care provider can diagnose asthma:

1) Health History

They will ask about your concerns, such as when you noticed you have trouble breathing, what it feels like, when your breathing becomes worse or better, and how long your symptoms have been going on, in addition to other important questions. A hallmark of asthma is when someone wheezes during exercise, when they are sick, are around animals with hair or fur, when the weather changes, or when they inhale dust or pollen, to name a few.

2) Physical Exam

Your diagnosis is also based on an assessment of your lungs, chest, nose, throat, and skin. An x-ray might be done, too. This helps the doctor rule out the possibility of other diseases. Wheezing during regular breathing is a sign of asthma.

                                          

3) Breathing tests

You will most likely be asked to do a few breathing tests. These are nothing to worry about. For example, the doctor might give you something called a "spirometer" (a hand-held device that measures how much air you can breathe in), and ask you to take as deep of a breath as you can. They also might test you with a "peak flow meter," which is a small device that you hold and blow into. When you blow out the air, a little line moves and tells you how well your lungs are working. The higher the number, the better (keep in mind that different ages will have different target numbers). You will do this then take medicine that is made to expand the airways. Then you will do the peak flow meter test again. If you are able to blow the line further, [specifically, if the volume of air you can blow out in 1 second increases by 10 or more (National Heart, Lung and Blood Institute & National Asthma Education and Prevention Program; p 65-66)] this means that the medication worked, and could mean you have asthma.

Left: Spirometer; RIght: Peak Flow Meter

4) There might also be allergy testing. Since asthma and allergies are closely related, the doctor might do this to see what could cause flare-ups.

Overall, what a healthcare provider will do is see if a) your symptoms match those of asthma b) your airway constriction is reversible with medications meant to help and c) rule out other causes (like COPD).

Disease Progression:

Diagnosis is important because then asthma control can be planned. Even when a person with asthma does not feel like they are struggling to breathe, there still might be airway inflammation. Over time, this damages the lungs. It can reduce lung function by permanently narrowing the airways and cause airway scarring over time. This is termed "airway remodeling," and occurs over time in an asthmatic, especially if their asthma is not controlled with medication. 

Sources:

I found   all of my information from the the sources listed below. The U.S. Department of Health and Human Services article is very long, in depth, and research-oriented, but if you like reading things like this is has a ton of information on what asthma is, how exactly it is diagnosed, and how it can be managed.

Asthma and Allergy Foundation of America. (2011) Asthma Overview: Diagnosis. Retrieved January 31, 2015, from http://www.aafa.org/display.cfm?id=8&cont=7

National Heart, Lung and Blood Institute & National Asthma Education and Prevention Program. (2007, August 28). Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma. Retrieved January 31, 2015, from http://www.nhlbi.nih.gov/files/docs/guidelines/asthgdln.pdf

The Asthma Center: Remodeling of the Airways. Retrieved January 31, 2015, from http://www.theasthmacenter.org/index.php/disease_information/asthma/what_is_asthma/definition_of_asthma/remodeling_of_the_airways_/

Who gets asthma?: It's complicated

In my second post, I explained an asthma attack/episode (the so-called "pathophysiology"), so to refresh your memory on this please take another glance! I also found another video that I think explains an asthma attack very well, and it goes into more detail than the last one I posted:

This week I am going to touch on what researchers believe puts a person at risk for developing asthma, although this process is not fully understood.

While genetics are thought to play a role, there are many other theories of why a person might get asthma. I found an article published in NCBI, titled "Asthma: epidemiology, etiology and risk factors" (2009), discussing that having a parent with asthma might increase a person's risk of developing it; however, it is not necessary. A person's risk is affected more by the environmental and lifestyle exposures they have experienced. The idea is that certain things from outside of our bodies can mess with certain bits of our genetic material inside our bodies, making them more defective.

So what are these factors that increase our risk besides possible family inheritance? While not fully understood, here are a few: Having a mother who smoked or was stressed during pregnancy, being exposed to cigarette smoke or animals early in life, exposure to mold (such as at home or in school), and exposure to chemicals in the air (such as pollution) or certain chemicals in one's workplace. Researchers have also found that people who have a lower socioeconomic status have a greater change of getting asthma. I once read that one possible explanation for this is that people who are unable to afford newer, safer housing are more likely to live in homes that cost less but as a result may not be as safe for a person's health (for example, housing that is located near a freeway where families will be exposed to fumes or mold-infested homes). 

Something else many people are curious about is why some people get asthma in childhood and later seem to outgrow it, and why some don't have it until adulthood. The NCBI article suggests that children are most affected by factors in pregnancy and early life, whereas adult-onset asthma is commonly related to repeated exposures at work. Below is a video about the myth of "outgrowing" asthma:

And on one final note, I am going to mention that the contributing factors to asthma deaths are also complex. After reviewing the actual disease process, discussed in my second post, it is easier to understand how the narrowing of the airways can cause death, but even with the same disease process, sadly, some people are more likely to die from asthma than others. This may be related to a number of factors, such as a person's desire to not take preventative medication, a person's inability to afford medication, and disparities in health care access among minority populations, to name a few. For more information, I encourage you to view this article:

https://www.aafa.org/pdfs/Disparities.PDF

Sources:

Subbaro, P., Mandhane, P.J., Sears, M.R. (2009). Asthma: epidemiology, etiology and risk factors. CMAJ: Canadian Medical Association Journal, 181(9), E181-E190. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2764772/

The Asthma and Allergy Foundation of America, The National Pharmaceutical Council. (2005). Ethnic Disparities in the Burden and Treatment of Asthma . https://www.aafa.org/pdfs/Disparities.PDF

Who's Most Affected? Asthma in the US

This week I will be giving a little bit of information on who is more at risk for asthma, based on recent trends. While searching for data from the past 5 years, I found that the overwhelming amount of the most recent nation-wide research is from 2007-2011 or 2012. I assume that more recent data is still being processed and put into documents by organizations such as the WHO and CDC. Once I find more recent data I will update this post. For now, here is what I've found:

• Approximately 1 in 12 people in the United States have asthma, and this trend has been and will likely continue to rise over time.

• More children than adults (9.5% vs 7.7%) and more females than males (9.2 vs. 7.0%) have asthma.
• People who identified as being of multiple races had the highest prevalence of asthma (14.1%), followed by African Americans (11.2%), Alaska Natives (9.4%), Whites (7.7%), Hispanic/Latino (6.5%), and Asians (5.2%). [I dislike when statistics clump many different ethnicities in such broad categories, but nonetheless it is often what happens in statistical analysis. If you choose to click on the link from where I found this information, the data table (figure 2) includes just a few more categories that have been broken down.]
• People of lower income are more affected , especially in households with an annual income below $15,000. Overall , the less income a family makes below the poverty line , the more cases of asthma we see. 
• According to the World Health Organization, asthma causes an estimated 25.6 million missed school/work days each year. 
• Asthma deaths, while rare, still do occur. According to 2010 data , asthma deaths have been decreasing, but they are most common among the elderly (over age 65), African Americans, and females. It is estimated that 9 people per day in the US die from asthma. 

Below I have added a nice picture from the CDC that includes their most updated nation-wide information on some of what I have mentioned and more:

Here is a map from the national Behavioral Risk Factor Surveillance System of people who reported having asthma in 2010. This map should give an idea of how asthma is distributed in the US, but use it with caution. Because this data is self-reported, there is a possibility of bias, as the population surveyed may not be an accurate representation of the total US prevalence. (For instance, there could be many more people unaccounted for in this survey, either because not everyone with asthma was questioned or did not have telephones to answer the survey, or there were people who did not wish to answer the survey, etc. The list goes on). What I personally take from viewing this map is simply the fact that asthma is distributed throughout the US.

Sources:

         Akinbami LJ, Moorman JE, Bailey C, et al. Trends in asthma prevalence, health care use, and mortality in the United States, 2001–2010. NCHS data brief, no 94. Hyattsville, MD: National Center for Health Statistics. 2012.http://www.cdc.gov/nchs/data/databriefs/db94.htm

       Asthma Facts: CDC's National Asthma Control Program Grantees. (2013, July 1). Retrieved January 16, 2015, from http://www.cdc.gov/asthma/pdfs/asthma_facts_program_grantees.pdf

         Asthma: Scope of the Problem in the USA. (n.d.). Retrieved January 18, 2015, from http://www.who.int/gard/news_events/21_casale_aaaai.pdf?ua=1

2010 Adult Asthma Data: Prevalence Tables and Maps. (2012, August 27). Retrieved January 18, 2015, from http://www.cdc.gov/asthma/brfss/2010/current/mapC1.htm

Asthma: An overview

            What really is asthma? More generally, it is known as an “immune-mediated inflammatory response.” In simpler terms, when your lungs come into contact with something that they don’t like/are extra sensitive to (known as “asthmatic triggers”), the immune system over-responds in a way that makes it more difficult to breathe. Different people can have different triggers, and a person without asthma is not as sensitive or may not be sensitive at all to the things that a person with asthma is.

Here is a brief explanation of what happens in an asthma attack: In response to the trigger, the lungs make too much mucous, plugging the airways. Also, the smallest branches of the airways (“bronchioles”) get much smaller, making it difficult for air to pass through. Instead of helping us, this immune response makes everything much worse.

Before we can understand the immune response, a basic understanding of the immune system in our lungs is necessary. There are special cells that live inside of your lungs and they are extremely important in warding off harmful particles in the air that you breathe in every day. For instance, there are cells that produce mucous (“mast cells”), and this sticky mucous catches germs. It is then moved out of the lungs by special cells (known as “ciliated” cells), or by coughing. There are also cells that, when they sense something harmful in the lungs, will warn other specialized cells so that they can come kill it. I like to think of these cells as watchmen of the lungs. Once they see a perceived enemy, such as a harmful particle, they send out an alert to recruit warriors to fight it. I think of it as this cartoon:

 

As you can see, we want these immune cells. In fact, we need them to survive. The problem in asthma, however, is that this response that is meant to protect us is taken too far. Inflammation is a normal response that helps kill harmful germs such as bacteria, but when we experience inflammation (and a lot of it) when we are around something that is normally not harmful, as is the case with asthma, it is certainly not helpful. Once the airways have narrowed and plugged with mucous, a person is said to be experiencing an asthma attack or episode. Upon breathing, they will experience wheezing (a sound made when air squeezes through narrow airways), shortness of breath (feeling like you are unable to get enough air), and coughing (due to increased mucous). Anyone with asthma will tell you how terrifying this can be. Here is a video that I feel explains an asthma attack well:

This concludes my overview (you may be thinking, that was only an overview?!), and I hope it has enhanced your knowledge about this complex disease in an understandable way.

Until next time,

Kaylin