Asthma rates started to decline in the 1970s, yet between 1980 and 1995 they increased 75 percent.  Rates have continued to climb since then, with an estimated 300 million people worldwide now diagnosed with asthma.  So what occured in 1980 to account for this steep incline?

Well, no on knows for sure, although there are theories.   Here are some of my theories why asthma rates have increased so much in recent years. 

1.  Tylenol (acetominophen):  In 1980 aspirin was linked to Reyes Syndrome, and since then Tylenol has been the pain reliever of choice for most doctors.  Surprisingly, graphs showing rising asthma rates match up with rising acetominophen rates.  Coincidence?  The makers of Tylenol say yes.  Scientists say asthma depletes gluthioline, which is a protein essential for immune system function.  Studies have shown inflamed cells have a low level of this protein, and people who take acetominophen have 40 to 60 percent greater risk of having asthma and allergies. For more on this click here. 

2.  Diagnosis Related Groups (DRGs):  A bill creating DRGs was signed in 1978 by President Jimmy Carter.  This made it so hospitals and doctors were paid a flat fee for each diagnosis, so that no matter how many procedures doctors ordered the hospital would be paid the same.  This was supposed to be an incentive to prevent doctors from ordering unnecessary procedures.  Surprisingly, it may have had the effect of doctors diagnosisng patients with certain diseases that are the most profitable, such as asthma.  Would your doctor conveniently diagnose you with asthma?  Well, I can't imagine you'd disagree with it if that diagnosis would guarantee your pulmonary function test or hospitalization was paid. 

3.  Air pollution:  Air pollution seems to get the blame for everything. However, despite contrary belief, air pollution rates have actually declined recently, which has caused many asthma experts to rethink the "theory" that pollution is responsible for rising asthma rates.  Still, it's an option that must remain on the table.  I wrote about the asthma and air pollution link in this post. 

4.  Improved methods of diagnoses:  In the past asthma was often diagnosed as other diseases, such as chronic bronchitis.  The way asthma is diagnosed has improved immensely in the past 30 years (learn how to diagnose asthma by clicking here).  This has helped doctors properly diagnose and treat this condition.  While this may help explain why asthma rates are going up, it also explains why the number of asthmatics visiting emergency rooms is declining, as I wrote here.

5.  We are too clean:  Our modern way of life has seen to it that we are clean.  Yet new evidence shows this lack of exposure to germs may make our immune systems bored.  Hence, a bored immune system starts attacking things that are normally considered safe, like your common allergens.  For more information see my post on the hygiene hypothesis.