<Tr> <Td_colspan="2"> Peak flow 50--80% best or predicted </Td> </Tr> <Tr> <Td_colspan="2"> No features of acute severe asthma </Td> </Tr> <P> An acute asthma exacerbation is commonly referred to as an asthma attack . The classic symptoms are shortness of breath, wheezing, and chest tightness . The wheezing is most often when breathing out . While these are the primary symptoms of asthma, some people present primarily with coughing, and in severe cases, air motion may be significantly impaired such that no wheezing is heard . In children, chest pain is often present . </P> <P> Signs occurring during an asthma attack include the use of accessory muscles of respiration (sternocleidomastoid and scalene muscles of the neck), there may be a paradoxical pulse (a pulse that is weaker during inhalation and stronger during exhalation), and over-inflation of the chest . A blue color of the skin and nails may occur from lack of oxygen . </P>

What is the definition of an asthma attack