We all know that our blood is red in color. But how our veins are blue?  What could be the reason?

Due to a major trickery that light performs on your eyes as well as how light reacts with our bodies and skin, veins seem blue.

Let us look at this topic in detail today.

Why Are Veins Blue?

The light must pass through the skin to highlight veins, thus they appear blue. Because red and blue lights have different wavelengths, they reach varying degrees.

As red has a longer wavelength, it can go deeper beneath the skin and be absorbed by hemoglobin.

While blue has a shorter wavelength than red, it does not reach as deeply beneath your skin. In a nutshell, blue light is the shorter wavelength that reaches your eye.

Role of Veins in the Human Body

• The tiniest and most abundant blood vessels are capillaries. They connect the blood vessels (arteries) that carry blood from the heart to the blood vessels (venous) that carry blood back to the heart. 
• Capillaries are small, thin-walled blood vessels that connect small arteries and venules; the exchange of nutrients and waste between blood and body tissues is carried out through capillaries. Veins are also called “capacitive vessels” because most of the blood volume (60%) is contained in veins.
• In the systemic circulation, oxygenated blood is pumped from the left ventricle through the arteries to the muscles and organs of the body, where its nutrients and gases are exchanged in the capillaries.
•  Through a network of arteries, veins, and capillaries, the blood carries carbon dioxide to the lungs (for exhalation) and collects oxygen. The blood flowing through the circulatory system carries nutrients, oxygen, and water to cells throughout the body. 
• Arteries and small arteries transport oxygen-rich blood and nutrients from the heart to organs and tissues, while small veins and veins transport oxygen-poor blood back to the heart. 
• Arteries provide the body with oxygenated blood-except for the pulmonary arteries of the heart; they carry deoxygenated blood to the lungs and umbilical arteries, which carry deoxygenated blood from the fetus to the placenta.
•  The blood begins its journey in the body again. Blood vessels come in a range of shapes and sizes, based on their function in the body. Oxygenated blood is pumped from the heart through muscle arteries. 
• As venules and veins come together to transfer blood to the heart through larger veins, veins are referred to be convergent or interconnecting vessels. Veins are also called capacitive vessels because they contain 60% of the body’s blood volume.
•  Once blood enters these deep veins, when these large muscles contract, the blood will be pumped to the heart, allowing the blood to pass through the circulatory system. In a healthy state, both the superficial and deep veins contain a functional unidirectional valve that allows blood to flow upwards to the heart but prevents it from flowing downwards. They receive blood from arteries through small arteries and capillaries.
•  The small veins branch into larger veins and eventually carry blood to the largest vein in the body, the vena cava. Small veins carry blood through the veins, which carry it back to the heart through the inferior vena cava.
•  Because the vein walls are thinner and less rigid than arteries, the veins can hold more blood. Thicker blood means people are at greater risk of blood clots in their veins and arteries, but the veins also have to work much harder to pump concentrated (denser) blood around the body. This, in turn, puts additional pressure on the veins inside and their associated valves, making it much more difficult to pump enough blood against gravity and return to the heart.
•  Veins are thin-walled blood vessels with one-way valves that transfer blood from tissues and organs to the heart. According to their structure and function, blood vessels can be divided into arteries, capillaries, or veins. These are tiny blood vessels between arteries and veins that carry oxygen-rich blood to the body.
•  Systemic veins carry blood from body tissues to the right atrium of the heart. In the lung circuit, the pulmonary veins carry blood from the lungs to the left atrium of the heart. The pulmonary veins carry oxygen-rich blood to the left side of the heart.

Difference Between Green and Blue Veins

The color of your veins mainly is connected with the undertone of your skin Veins on the top layer of the skin that have a warm undertone will seem green or blue. If your skin has cool undertones, your veins will seem blue.

The skin undertone is a color beneath the surface of the skin that reflects the skin’s primary color. When analyzing green vs. blue veins, warm undertones indicate green veins, whereas cool undertones indicate blue veins.

When To Consult Your Doctor

If your blue veins appear to be bulging or becoming uncomfortable in any way, visit your doctor. Some symptoms of venous insufficiency include the following. When the veins in the legs wouldn’t enable blood to circulate right back to your heart, this is known as venous insufficiency.

Dilated veins, inflammation, and a change in the color of your legs as a result of blood accumulating in your legs are all common symptoms of venous insufficiency. This causes skin irritation, which might manifest as the following symptoms:

• Itchiness
• Sores that have not healed yet
• Redness
• Dryness
• A fluid that is dripping
• Areas that are glistening and hard
• Ulcers are another possible complication of venous insufficiency, which, if left untreated, can turn into something extremely unpleasant.

Another issue is varicose veins. The most obvious sign of varicose veins is the blue or purple nodular veins under the surface of the skin. 

People with varicose veins are more likely to form blood clots. In some cases, severe varicose veins can cause serious health problems, such as blood clots. Thrombus can form in varicose veins, leading to a condition called superficial vein thrombosis or superficial thrombophlebitis.

Final Words

With the help of this article, you have understood why our veins appear blue. And also the difference between green and blue veins. For health reasons, veins rarely require treatment, but if there is swelling, pain, and pain in the leg, or if there is significant discomfort, it can be treated.