The report says Gaza's 1.4 million people are increasingly preoccupied with obtaining basic supplies such as water and food.
The U.N. Office for the Coordination of Humanitarian Affairs says unemployment now stands at 49 percent, up from 32 percent a year ago. Thursday's report says residents of Gaza City are without power for up to 16 hours a day. Half the city's residents receive water only once a week for a few hours.
Israel and Egypt sealed Gaza after the Islamic militant Hamas seized power 18 months ago. Israel intensified the closure after more fighting in November.