THURSDAY, Dec. 30 (HealthDay News) -- A new Swedish study shows that severe asthma seems to be more common than previously believed. It also reports that those afflicted by it have a higher prevalence of blocked or runny noses, a possible sign that physicians should pay more attention to nasal congestion and similar issues.

In the study, researchers surveyed 30,000 people from the west of Sweden and asked about their health, including whether they had physician-diagnosed asthma, took asthma medication, and if so, what kind of symptoms they experienced. "This is the first time that the prevalence of severe asthma has been estimated in a population study, documenting that approximately 2 percent of the population in the West Sweden is showing signs of severe asthma," study co-author Jan Lotvall, professor at Sahlgrenska Academy's Krefting Research Center, said in a news release from the University of Gothenburg.

"This argues that more severe forms of asthma are far more common than previously believed, and that health care professionals should pay extra attention to patients with such symptoms," Lotvall added.

The researchers also found a link between severe asthma and long-lasting nasal congestion and runny nose, which was more prevalent in those with severe asthma compared to those with fewer asthma symptoms. Lotvall said this means that patients who have nasal problems -- possibly in conjunction with wheezing, shortness of breath during exercise, and awakenings during sleep -- should be checked for asthma.

"These findings suggest that some parts of the immune system that are activated in connection with chronic nasal problems might be linked to severe asthma, and this insight could lead to new forms of treatment in the long run," Lotvall said. "Effective treatment for troublesome nasal and sinus complaints could, in theory, reduce the risk of severe asthma, though this is something that needs further research."

The study findings were published in a recent online edition of the journal Respiratory Research.

More information

For more on asthma, try the U.S. National Heart, Lung and Blood Institute.