Overpopulation is also known as overabundance, happens when the population grows to a point and when it must be handled. The major reason for overpopulation is rise in birth and decrease in mortality. When the population increases the resources will become insufficient for the whole population in the nation.
We can say a few causes for overpopulation like, international migration, decrease in death rate.
International migration: people were migrating from their native to other places because of many reasons, like employment opportunities, marrying another nation people. when they migrate to another nation or place then they start their life in that nation. It is human nature that when a person feels, the present place is better than the previous place then he/she will much prefer to stay where they are at present. This may be the first reason to increase the population of one particular nation.
Decrease in death rate: The decline of death rates can be caused by good knowledge about welfare policies, and a healthy lifestyle, which improves the environment to lead a good lifestyle. Also there are more medical facilities, controls of epidemics, control over famine. Not only the above mentioned are reasons for decrease in death rate.
When population increases there will be an equal reflection of effects that are also increasing, insufficient resources like, water shortage, deforestation, global warming, depletion of natural resources.
In conclusion, With overpopulation a nation will face a greater problem. People should be educated with the effects of overpopulation to control the increase in population.