While many people have problems with hunger and weight gain, in a very small number of people, hard-to-control hunger (hyperphagia) can be because of a problem in an area of their brain.
The key part of the brain that helps control your hunger is called the hypothalamus.
People may be born with a problem with the genes in the hypothalamus (you can learn more about the link between genes, hard-to-control hunger and obesity on this page).1
However, instead of a problem with their genes, people can have an accident or illness causing damage to the hypothalamus. This is a rare non-genetic cause of hard-to-control hunger and obesity, which doctors call acquired hypothalamic obesity.
If you or someone you care for have this you will likely already be looked after by a doctor for the injury or illness, and they will be able to advise you on the next steps.2