Dirty and clogged gutters can lead to big problems.
Poor drainage can cause damage to any number of areas in and around your home, even the home foundation. Piles of leaves rotting in the gutters attract pests. The weight of debris can eventually separate the gutters from the home.
Clean your gutters! Twice a year and after major storms.
Check out this article for more information: https://www.angieslist.com/research/gutter-cleaning/