The green nose may be caused by physiological factors or pathological factors or trauma and other factors, the common causes and formation process are as follows: 1, physiological factors: common in infants and young children, may be due to the baby’s relatively small months, the skin itself is more white and tender, the capillaries under the bridge of the nose will be more obvious, so there is the case of nasal bridge blue, generally will gradually fade with the growth of children’s age. In addition, people who often wear glasses, the mirror rest will repeatedly squeeze the bridge of the nose, will also cause the superficial veins of the bridge of the nose dilated blue, you can massage the bridge of the nose more, to promote local blood circulation; 2, pathological factors: such as vitamin C deficiency, long-term unbalanced nutritional intake may lead to nasal skin blue symptoms. Patients with blood disorders have poor blood circulation in the organism, there will be a local lack of oxygen, and the skin tissue at the bridge of the nose is thin, which in turn shows a more obvious cyanosis. Cyanosis on the bridge of the nose in young children can be seen in asthma or heart disease, and may also be caused by carbon monoxide poisoning. In addition, when suffering from nasal polyps, deviated nasal septum or sinusitis and other diseases, the relatively long time swelling and blockage affect the local blood circulation, may also cause the bridge of the nose blue; 3, trauma factors: the bridge of the nose area by the external force of the storm will lead to soft tissue damage, capillary rupture, subcutaneous bruising, resulting in bruising. This situation needs to go to the hospital for nasal CT examination to further clarify whether there are nasal fractures, etc.; 4, other factors: if the liver detoxification function is poor, the human body will occur indigestion, nasal bridge bruising and other symptoms.