The cause of asthma is unidentified. However, it is well known that more children develop asthma if they have allergies, or if one or both of their parents have asthma or allergies.
Asthma symptoms can develop at any age. How each child is affected can vary with age. The airways of an infant/toddler are more easily obstructed because of their smaller size. This age cluster can therefore be prone to more obvious symptoms. As the child grows, these symptoms might decline.
Most do not experience long-term physical effects of asthma, but constant and poorly-controlled asthma may have a prohibiting effects on growth, and may result in reduced lung function as an adult. As with any chronic disease there may be an emotional effect on children with asthma. Emotions such as annoyance, anxiety, depression, hopelessness and guilt may be experienced.