Sir i am eating pencil leads ! how can i have to stop eating like those leads? and it will harm to my body?

PIca: ...is characterized by an appetite for substances that are largely non-nutritive, such as paper, clay, metal, chalk, soil, glass, sand, or in your case pencil leads. Because pica can occur in people who have lower than normal nutrient levels & malnutrition, your doctor may want to test blood levels of iron & zinc. Also seen with autism, schizophrenia, & disorders such as Kleine-Levin syndrome.