Some of the countries in the world are classified as overpopulated. This means that there are too many people in the country for the amount of resources that are available. Geographers make the distinction that a country is overpopulated if the population numbers less than one million but there are only natural resources available that number half of the population.
In cases like this people are probably not going to have the basic things they need because there simply is not enough to go around. Overpopulated countries will probably have a high mortality rate as well as a problem with diseases since all the people do not have access to the basic things needed to live.