As wards of the state, foster care children are dependent on government-funded health services. As a group, children in foster care suffer high rates of serious physical or psychological problems. Nearly half of these children suffer from chronic conditions such as asthma, cognitive abnormalities, visual and auditory problems, dental decay and malnutrition, as well as birth defects, developmental delays or emotional and behavioral problems. Over half require ongoing medical treatment. Studies indicate that well over half have moderate to severe mental health problems. These conditions stem from exposure to alcohol and drugs, lack of medical care, poor parenting, domestic violence, neglect, and unstable living conditions prior to family removal. The trauma of family separation, frequent moves, and the stress and disruptions brought about by impermanent placements in the foster care system aggravate the situation. Children in foster care typically suffer serious health, emotional, and developmental problems.