Washington: A new study has suggested that nasal congestion can be a sign of severe asthma. This means that healthcare professionals should be extra vigilant when it comes to nasal complaints. Furthermore, more severe asthma appears to be more common than previously thought, reveals a study from the Sahlgrenska Academy``s Krefting Research Centre. The population study included 30,000 randomly selected participants from the west of Sweden and asked questions about different aspects of health. "This is the first time that the prevalence of severe asthma has been estimated in a population study, documenting that approximately 2pc of the population in the West Sweden is showing signs of severe asthma," said Jan Lotvall, one of the authors of the study and professor at the Sahlgrenska Academy``s Krefting Research Centre.