To contract a disease; to become ill (often used for catching or developing a specific illness).
旅行中に病気にかかって早めに帰国した。
I fell ill while traveling and returned home early.
子どもがはしかに病気にかかって、学級閉鎖になった。
A child contracted measles and the class was closed.
予防接種で病気にかかるリスクを減らせることが多い。
Vaccination often reduces the risk of contracting diseases.