How did Adrian Monk's mom die?

Answer 1

It is never explained how she died, but she died in 1994, and in Mr. Monk and the Big Game, he says she still came to his track meets even "when she was dying", so it couldn't have been sudden, like a car wreck. It might have come as a result of a psychological issue, because she changed drastically after Monk's father left in much the same way as he did when Trudy died. Also, in Mr. Monk and the Three Pies, Ambrose thinks that when he broke one of the numbered mugs, the psychological stress may have been a contributing factor to her demise. That's about all they've said on the show, but just a little interesting fact, if you want to see his mother, she appears in one flashback in the episode Mr. Monk and Little Monk.