Here’s The Interesting Reason Why Your Veins Are Blue

why are veins blue cover image

Looking at your arms or on the lateral side of your wrist and you might notice a network of blue/green veins running across. Some might see it in their legs, feet, hands, forearm, etc. Some people have veins that are deep blue, some have green and some can’t even discern the color of the vein. So if blood is red, then why are veins blue? The answer is, veins are not blue but the light it reflects through the skin is blue and hence you see a shade of greenish-blue.

Understanding colors

Without getting into details, let me explain in brief terms how color works. When you see something that is red, the red color is because when white light falls on that object, most of the colors are absorbed while only red is reflected. This reflected red light makes the object appear red.

White light is made of multiple colors (the colors of the rainbow). Each color has a wavelength with a specific energy. That’s all you need to know to understand the color of veins. Here’s why your veins’ color made you think you were a “blue-blood”.

Veins aren’t blue, they just look blue
Seeing those medical diagrams which represent arteries with red color and veins with blue might in a subliminal way make you think that veins are blue. But that’s not the case. It is due to the position of the vein and the presence of other proteins that gives them the deceptive blue color.

Even the most superficial veins are not placed directly under the skin. The skin has an epidermis, endodermis, and a layer of fat. This along with some protein distorts the light that falls on the veins.

Another great place to see this shade of veins is under the tongue. Since the skin is very thin there, you can see the network of superficial, indigo-colored veins.

Red has a longer wavelength while blue a shorter one. This allows red to penetrate deeper into the skin without being reflected off but blue is scattered easily. So when white light falls on the veins, red is absorbed deeper while blue is reflected. This gives the veins a greenish-blue color.

So the blue color of the veins is due to the scattering and reflection of blue light due to the layers of fats and protein over the superficial veins. This is also the reason why the sun appears orange or red during the morning and evening. Since the sun rays pass through more air (and particles), blue and violet light gets scattered and red light reaches us.

visual explanation for the apparent blue color of veins
visual explanation for the apparent blue color of veins

Blood is always red, never blue

Another misconception people have is that deoxygenated blood is blue-white oxygenated blood is red. This is not true. Blood is never blue. Blood with more oxygen (in the arteries) is bright red while blood with less oxygen is dark red. Dark red under the skin appears blue. The lesser the oxygen, the bluer the vein appears.

So what’s the actual color of veins? Veins are thin-walled, unsupported vessels that are mostly colorless. So if you removed the skin and saw the vein (which I highly advise against), the vein will look red.

Are blue veins a sign of some disease?

Blue superficial veins such as the veins in the wrist, under the eyes, under the tongue, etc are perfectly normal. There is nothing to worry about them. However, sometimes blue veins that are not superficial might be a cause of concern.

If you notice a cluster of tiny blue veins in your legs, arms, chest, or if the number of blue veins in your body keeps increasing (visibility), it is better to consult the doctor to be on the safer side. There’s nothing serious to worry about, but you might be suffering from varicose veins or similar conditions.

Sometimes, exercising can also cause the veins to pop out and appear blue. This is due to a decrease in oxygen in other parts of the body apart from the muscles. And since exercise stimulates muscles, this results in the “popping of veins”.

Why Royal people were called “Blue-Blooded”
You may have heard that royal people were considered to be blue-blooded. This was prevalent in the European countries. The reason for this change of color was also due to veins’ appearance.

The royals were always inside their castles, in utmost care. This reduced the melanin in their skin, giving them a pale appearance. The labor class worked in the sun and let’s be honest, they weren’t living a life of luxury. The exposure to the sun and the lack of sunscreen increased their melanin and hence made them darker. And dark skin does not show blue veins. So this is how the royals were called “blue-blooded”, only in Europe.

Dark circles? More like blue circles

Staying up late to finish the work or finish that Netflix series in one sitting, dark circles are bound to come. The misconception people have is that dark circles are something that occurs on the skin. But in reality, it’s just the veins getting an excess supply of blood

When you strain your eyes to work late and not sleep, more blood is supplied to it. This also results in more blood flow in the veins around it. The skin under our eyes is very thin and hence, you see the bluish color under it, called the dark circle.

This concludes the article. But it should not be the end of reading. Take a look at these interesting articles;

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