Smoke

• Secondhand or third-hand smoke, which is smoke residue left in fabrics and on surfaces, can trigger asthma attacks.
  
  

Air Pollution

• Air pollution from factories and automotive exhaust can increase your risk of asthma, as well as cause asthma attacks.
  
  

Chemicals

• Chemicals used to clean your house, pesticides and herbicides, and chemical exposures in manufacturing jobs are risk factors that may cause asthma.
  
  

Infections

• Frequent infections from the common cold and other respiratory illnesses such as bronchitis and pneumonia may increase your risk of developing asthma later in childhood or as an adult.
  
  

Overweight

• Being overweight or obese requires more oxygen for your body's muscles and puts pressure on your lungs, which increases your risk of asthma.
  
  

GERD

• Gastroesophageal reflux disease (GERD) can increase your risk of asthma by causing chronic irritations to your throat and breathing passages.
  
  

Premature Birth

• Premature birth (before 37 weeks of gestation) and a low birth weight increase your risk of asthma due to underdeveloped the lungs at birth.