Kyle B. Knott, 18, of 351 Jelliff Mill Road, New Canaan, was arrested April 7 on charges of disorderly conduct and second-degree reckless endangerment.
Police received a 9-1-1 call at 8 p.m. from Knott's sibling, who reported a dispute between Knott and their mother, according to police.
When officers arrived, Knott's 43-year-old mother said the two were having an argument when her son pushed her down the stairs, police said. The woman said she wasn't injured, but a portion of the railing broke off during the incident, according to the report.
Police said Knott also caused some damage to his own room, where he knocked over and broke a lamp and a coat rack.
Knott also was issued infractions for possession of less than half an ounce of marijuana and possession of drug paraphernalia after police discovered a pipe and small amount of marijuana in his room, according to the report.
He was held in lieu of $2,500 bond and was scheduled to appear in court April 8.