Lead poisoning occurs when lead is ingested or inhaled and can damage the brain, nerves, and other organs. It can be acute from a large amount over a short period or chronic from small amounts over a longer time. Symptoms in adults include headaches and mood disorders while symptoms in children include abdominal pain and learning difficulties. Treatment involves diagnosis with a blood test and preventing further lead exposure through changes at home or work. Lead affects multiple organ systems like the heart, nerves, and kidneys. It also increases risks of dental issues like cheilitis.