1, bright red
Most of the arteries in the human body are located in the deeper part of the body and are not easy to see. The blood flowing in the artery is bright red because it contains more oxygen. Therefore, the blood taken from the distal part of the artery, such as the earlobe or fingertip, or the blood flowing out after skin trauma is often red or bright red. In addition, the blood of patients with mild anemia is also bright red.
2. Deep red or black red
The blood flowing in veins is venous blood, which is dull because it contains more carbon dioxide and other metabolites. When doing blood tests, blood is usually drawn from the elbow vein, so the blood drawn is often dark red or black red, which also shows that your blood contains more red blood cells and hemoglobin.
3. Black and purple
In addition, when the blood is concentrated or the venous blood of patients with cor pulmonale can be dark purple. It is also possible to see that the blood color is dark when taking blood from the distal parts such as fingertips, similar to venous blood. This is because most of them come from one end of peripheral vein or are caused by factors such as high hemoglobin concentration and blood concentration.
4, cherry red
It is suggested that gas poisoning has occurred in human body, which leads to the combination of hemoglobin and carbon monoxide or the loss of oxygen carrying capacity of carbohemoglobin. When the carboxyhemoglobin reaches 30%-40%, not only the blood is cherry red, but also the skin on the face, chest and inner thigh is cherry red.
5, brown or purple black
It is suggested that human body suffers from nitrite poisoning or enterogenous cyanosis. When a large number of pickles or spoiled leftovers containing more nitrate are eaten, intestinal bacteria will reduce nitrate to nitrite. Nitrite is a strong oxidant, which can oxidize ferrous iron in hemoglobin into trivalent iron, thus losing its oxygen-carrying function and leading to hypoxia in human tissues.