祖父は去年の冬から寝付いたままだ。
My grandfather has been confined to bed since last winter.
母が風邪をこじらせて三日ほど寝付いてしまった。
My mother's cold got worse and she was laid up in bed for about three days.
一度寝付くと、体力が落ちてなかなか回復しない。
Once you are laid up in bed, you lose strength and it takes a long time to recover.