According to a study:
Moms who are stressed-out (angry or irritated or suppressed their emotions) make their child’s asthma worse. The findings suggest a mother’s stress may be conveyed to the child, either through words or behaviors.
Studies have shown that sadness induces airway contraction, which may worsen asthma symptoms, while happiness induces airway relaxation.
(The study involved 273 mothers of children with asthma, ages 2 through 12, who visited the National Fukuoka Hospital in Japan)