Unlike Britain, the US does not have a national health care service. Most people buy medical insurance to help pay for medical care. The US government only helps pay for some medical care for the old and the people who are on low incomes. The problems of those who cannot afford insurance have become an important political subject. In Britain, when people are ill, they usually go to a family doctor first. However, people in the US sometimes go straight to an expert. Children are usually taken to a doctor who is an expert in the treatment of children. In Britain,if a patient needs to see a specialist, his family doctor will usually recommend a specialist, which will save more time and money both for the patients and the public fund. In Britain, doctors do not go to people's homes when they are ill. People always make appointments to see the doctor in the doctor's office. In a serious situation, people call for an ambulance. In the US,hospitals must treat all seriously ill patients, even if they do not have medical insurance. The government will then help pay for some of the cost of the medical care.