To ruin can be used as a verb to mean the action of destroying or damaging something. For example, dishonesty can ruin a relationship; although, truth be told, honesty can also ruin a relationship!
An ugly block of flats can ruin a view and putting food in a microwave often ruins the taste. Teenagers always say their parents are trying to ruin their lives and dentists always warn us that eating sweets is bound to ruin your teeth. So, what’s ruining you life at the moment?