Serum ferritin is a commonly used marker and its elevation needs to be combined with the presence or absence of overweight and fatty liver in the patient. Increased serum ferritin may be closely related to long-term obesity and insulin resistance. In the case of insulin resistance, increased ferritin needs to be accompanied by timely and reasonable weight loss and improvement of fatty liver status, which may lead to a certain degree of regression and sometimes improvement by correcting metabolic disorders. Ferritin is also prone to changes among pregnant women and can be used as a marker of inflammation, which can occur in inflammatory states, such as acute infections, and may also increase to a certain extent, but is often a short-term acute change process. There are also diseases of the immune system, when a patient has a prolonged high fever and rash with a significant increase in ferritin, and in clinical situations where ferritinemia is persistently elevated and a long-standing fever with a significant rash, but the cause is not clear, one should be alert for adult Stills disease, formerly called variant subacute sepsis, and children with Stills disease where ferritin is significantly elevated. Ferritin is also a tumor marker, and some tumors in the body may potentially show increased ferritin, requiring further investigation.