High ferritin of more than 1000 is not very common and is most commonly seen in malignant tumors such as lung cancer, acute hepatitis and hemolytic anemia. Ferritin is a kind of protein which contains the most abundant iron in the body, and widely exists in liver, spleen, kidney and bone marrow. Serum ferritin is an important index of iron storage in the body, and it can be used as a kind of tumor marker, which has certain reference value for the diagnosis of certain malignant tumors. 1. Malignant tumors: such as lung cancer, liver cancer and other cancer cells synthesize increased ferritin, so that serum ferritin is elevated. 2. Acute hepatitis: due to the damage of liver cells, the function decreases, the ferritin stored in liver cell plasma overflows into the blood, so that the serum ferritin is elevated. 3. Hemolytic anemia: due to the destruction of blood cells, after metabolism, ferritin will rise, and iron deposition in the liver, pancreas and other places can lead to serum ferritin elevated more than 1000. High ferritin more than 1000 has a certain degree of danger, should be improved as soon as possible to clarify the cause of the disease, under the guidance of the doctor standardized treatment.