Fibrinogen is an important protein fibrin involved in the process of coagulation and hemostasis. The increase of fibrinogen can indicate that the blood is in high coagulation or high viscosity state, and the main reasons are divided into physiological factors and pathological factors. 1. Physiological factors: for example, in the late stage of pregnancy, due to the increase of circulating blood volume, fibrinogen also increases compensatory increase, which enhances the coagulation function of the body, in addition, it may also be related to high age, long-term smoking, strenuous exercise, taking estrogen drugs and other physiological factors. 2. Pathological factors: a variety of diseases can lead to increased fibrinogen, such as atherosclerosis, diabetes mellitus and ketoacidosis, renal diseases such as acute and chronic nephritis, multiple myeloma, rheumatism, pre-thrombotic state, connective tissue disease, hyperlipidemia, etc., or shock, burns, acute infections, post-surgery and so on. The presence of increased fibrinogen, it is recommended to promptly seek medical attention, through further examination in order to clarify the cause of the disease, under the guidance of the physician treatment.