Common childhood asthma signs and symptoms include:

• Frequent coughing that worsens when your child has a viral infection, occurs while your child is asleep or is triggered by exercise or cold air
• A whistling or wheezing sound when breathing out
• Shortness of breath
• Chest congestion or tightness

Childhood asthma might also cause:

• Trouble sleeping due to shortness of breath, coughing or wheezing
• Bouts of coughing or wheezing that get worse with a cold or the flu
• Delayed recovery or bronchitis after a respiratory infection
• Trouble breathing that hampers play or exercise
• Fatigue, which can be due to poor sleep

Asthma signs and symptoms vary from child to child, and might get worse or better over time. Your child might have only one indication, such as a lingering cough or chest congestion.

It can be difficult to tell whether your child's symptoms are caused by asthma. Periodic or long-lasting wheezing and other asthma-like symptoms can be caused by infectious bronchitis or another respiratory problem.

Childhood asthma causes aren't fully understood. Some factors thought to be involved include:

• Inherited tendency to develop allergies
• Parents with asthma
• Some types of airway infections at a very young age
• Exposure to environmental factors, such as cigarette smoke or other air pollution

Increased immune system sensitivity causes the lungs and airways to swell and produce mucus when exposed to certain triggers. Reaction to a trigger can be delayed, making it more difficult to identify the trigger. Triggers vary from child to child and can include:

• Viral infections such as the common cold
• Exposure to air pollutants, such as tobacco smoke
• Allergies to dust mites, pet dander, pollen or mold
• Physical activity
• Weather changes or cold air

Sometimes, asthma symptoms occur with no apparent triggers.

Factors that might increase your child's likelihood of developing asthma include:

• Exposure to tobacco smoke, including before birth
• Previous allergic reactions, including skin reactions, food allergies or hay fever (allergic rhinitis)
• A family history of asthma or allergies
• Living in an area with high pollution
• Obesity
• Respiratory conditions, such as a chronic runny or stuffy nose (rhinitis), inflamed sinuses (sinusitis) or pneumonia
• Heartburn (gastroesophageal reflux disease, or GERD)
• Being male
• Being black or Puerto Rican

Asthma can cause a number of complications, including:

• Severe asthma attacks that require emergency treatment or hospital care
• Permanent decline in lung function
• Missed school days or getting behind in school
• Poor sleep and fatigue
• Symptoms that interfere with play, sports or other activities