Nails are dark purple. What happened?

Human nails can reflect the physiological and pathological changes of human body, such as milky white nails: kidney or liver diseases; Blue nails: circulatory disorder; Yellow nails: bronchitis; Red lines appear on nails: hypertension, rheumatism or heart disease; Transverse furrows on nails: fatigue, tension, excessive anxiety and lack of nutrition; Nails are glassy: liver atrophy, tuberculosis; Yellow a: more common in jaundice; Purple nail: common in heart disease and blood disease; White spot: It means that there is ascaris or a viral cold recently, and people with calcium deficiency are also prone to white spots. Typical blood stasis performance, temperature rise accelerates blood circulation and naturally restores its true colors. Have you ever hurt your nails before, and then the bleeding accumulated under them and turned purple? It is also possible that your blood circulation is not smooth. You'd better go to the hospital for examination. Red nail bed indicates qi-blood heat syndrome. Those who are ruddy are slightly ill, and those who are red and withered are seriously ill. Bleeding of nail bed also belongs to red nails. If there is spindle-shaped longitudinal linear bleeding on the free edge of the nail, it can be seen in coagulation dysfunction, drug allergy, subacute endocarditis and so on. Therefore, if there is no nail congestion caused by trauma, it is recommended to do blood routine, electrocardiogram and color Doppler ultrasound. Just rule out heart disease and blood system diseases.