Blood is a key component of our body, and it is involved in our daily lives. If you accidentally cut yourself, you will see bright red blood. In TV dramas, the blood that flows out of the injured person usually has different colors. Let’s find out the reasons together below.

What does the blood of a normal person look like? Is it bright red or dark red, and is it healthy and fit?

Blood is a thick, opaque, bright red liquid that flows in the human blood vessels and heart. The color of blood varies, and the bright red color of blood comes from the hemoglobin concentration in the blood cells. When the hemoglobin concentration contains more oxygen, it appears red (arterial and venous), and when the oxygen content is less, it appears dark red (venous blood).

Generally, the blood drawn for donation is venous blood, so it looks dark red in appearance. If the blood contains a large amount of high iron hemoglobin concentration or other hemoglobin concentration compounds, it will appear purple and black.

Blood (or blood cells) may appear translucent light yellow due to a small amount of total bilirubin; if it contains chylomicrons, it will appear milky white and turbid; if hemolysis occurs, it will appear bright red.

The light red color of the blood may indicate anemia.

If the blood appears light red, it is more likely to be anemia. The hemoglobin concentration in 1000ml of normal blood is 121.6 grams for men and 111.5 grams for women. If it is lower than this standard, it is considered anemia.

Therefore, the lower the hemoglobin concentration, the more severe the anemia, and the color will also change from bright red to light red.

The dark red color of the blood may indicate insufficient oxygen.

The blood is dark red, with a color similar to that of a large cherry, which is generally one of the manifestations of hypoxia. Generally, when the amount of carbon dioxide accepted by the blood exceeds the oxygen content, as the level of insufficient oxygen becomes more severe, the color of the blood also becomes darker. Patients with emphysema or pulmonary heart disease usually may have such signs.

In addition, if the blood shows such color changes, it may also be a sign of carbon monoxide poisoning, because in carbon monoxide poisoning, the hemoglobin concentration combines with carbon monoxide to form carboxyhemoglobin, losing its ability to carry oxygen and causing oxygen deficiency in the body. In addition to the change in blood color, the lips, mucous membranes, facial, chest, and thigh root skin showing such color are also signs of carbon monoxide poisoning.

Milky white blood indicates an excess of fat

Milky white blood with a dirty shape generally indicates that the amount of fat and protein in the blood is too high. In medicine, this kind of blood is also called ‘chyle blood’.

In addition, the appearance of fresh blood that is milky white may also be a sign of diabetes or arteriosclerosis, and it is necessary to achieve the goal of cure by adjusting the diet and actively treating it.

Dark purple blood may indicate lung disease

Purple-red blood may be a sign of insufficient oxygen in the body. Generally, when the oxygen and hemoglobin concentration in the blood decreases, and the concentration of reduced hemoglobin rises to more than 5 grams of hemoglobin per 100 milliliters of blood, the blood will turn purple-red.

Generally, such a condition indicates that the patient has serious emphysema, pulmonary heart disease, or cyanotic congenital heart disease, and needs to be treated as soon as possible.

Brownish blood may be due to food poisoning

Blood that is blackish-brown may be due to the ingestion of food containing sodium nitrite, such as phosphate or pickled meat products with a high content of sodium nitrite, sauerkraut, moldy vegetables and fruits, and food prepared with ‘industrial salt’, which may cause nitrite poisoning.

In different blood vessels, blood presents two colors due to the different amount of CO2 it contains: red and dark purple. After absorbing enough CO2 in the lungs, the blood is red, and after delivering oxygen to all parts of the body, the CO2 decreases, and the color changes to blue-purple.

This blue-purple blood turns into a bluish-green color through the skin and blood vessel walls of the hands and feet. The red blood with a lot of CO2 in the deepest blood vessels of the skin is not visible.

Another way to put it is that if you look at something through a colored glass sticker, the color of the thing will become different from the original color. The same principle applies, the blood vessels we can see on the skin are veins, and the blood flowing in the veins is deep red. This deep red is obscured by a layer of pale yellow skin, so it looks green.

Although blood is bright red, it is different from blood vessels, which originally appear green. For example, if you take a pale yellow rubber water pipe and fill it with drinking water, can you say: Drinking water is originally colorless! Why does the tap water pipe look pale yellow? In fact, the pale yellow is the color of the tap water pipe, which has nothing to do with the water solution inside.

Like our blood vessels, although they contain bright red blood inside, the blood vessels are composed of endothelial cells and some connective tissues, and naturally have their own color.