Why Is My Blood So Dark

Why Is My Blood So Dark And Red?

Blood is the most important fluid which sustains life within our body by supplying oxygen to all our body parts and the cells of these body parts. It is an important life giving substance which should be taken care of. However, along with being the life saving fluid, it also acts as an indicator of our well being.

That is the reason, in case of any health ailment, a blood test is prescribed since the blood test is one test which can reveal the exact health parameters and the exact causes of any health ailments if any. Following the blood color and taking a clue from the blood color is one of the essential tricks to estimate the health of our body.

Why is Blood Red in Colour?

Human blood is originally red in color. The human blood helps in transporting the most vital substances such as minerals, oxygen, and other essential compounds across different parts of the body. However, under certain serious health conditions, the blood becomes dark and at times almost black. It is important to understand the conditions and the reasons why your blood is so dark?

The healthy human blood color is bright red. This is because the blood of human beings carries oxygen to all the parts of the human body. Well, oxygenated human blood has the healthy blood color of bright red due to the presence of hemoglobin, the respiratory pigment, which is responsible for transporting oxygen to the tissue cells.

Why Is My Blood So Dark?

However, when the human blood becomes deoxygenated, under specific circumstances, the blood tends to get dark and usually is dark red, blackish red, or maroon in color. This dark blood indicates health problems. At times, human blood can also tend to be brown, green or dark red (almost black) in color because of some abnormal form of hemoglobin.

Blood flowing in human veins is darker in color since the oxygen carried by blood has already been delivered to the different cells of the body. Thus the veins carry the lowest oxygenated blood. Most of the wounds and cuts in human beings make blood flow from the veins since the veins are near the outer surface of the skin. Since commonly the cuts impact the veins, the blood that we see flowing out is dark red in color. In fact, in case of bight red color blood is seen oozing out of a wound, it should be immediately checked with the doctor since this might indicate a severed artery.

Thus, the most common cause of dark blood is due to the reduction of oxygen levels in the blood. More the oxygenation of blood reduces darker the color of the blood gets. Apart from this, there are certain cases of blood poisons which can cause the blood to get a rust color which might not be as dark as black but certainly not the healthy blood color.

Methemoglobinemia is a health condition in which blood appears to be of chocolate brown color. In this health condition, Methemoglobin, a type of hemoglobin, forms within the blood which does not carry oxygen. This reduces the oxygen carrying capacity of the blood, thus increasing the viscosity of the blood which makes it appear darker. Another important cause of dark and thick blood can be old and stagnant blood such as menstrual blood.

Dark red and thick blood indicates low oxygen carrying blood. Blood thickness and viscosity is caused due to the presence of heavy proteins in the blood. Usually, blood clots are comprised of heavy proteins and thus are thick. These thick blood clots cut off oxygen flow, thus affecting the color of the blood. Thick blood also indicates the large volume of blood in circulation in the specific area. Too many red blood cells, white blood cells, and platelets result in thickening the blood.

It is important to understand where the dark blood is coming from or the source of the dark blood would determine whether it is healthy or not. If the blood comes from the pulmonary vein while on the way to the lungs, then the dark blood has a valid reason. However, in case the dark and thick blood is sourced from the pulmonary artery (artery which returns blood to the heart), this indicates that the person is nearing death due to severe anemia. The causes of such dark blood in the pulmonary artery could be chemotherapy, liver, kidney and heart failures, or COPD.

In order to maintain a healthy body, it is important to analyze why your blood is so dark in color? And such an analysis should happen timely. The only cure of maintaining a healthy blood color is to treat the underlying cause of such thick and dark blood.

Medically Reviewed By
Dr. Kaushal M. Bhavsar (MBBS, MD)Assistant Professor in Pulmonary Medicine, GMERS Medical College, Ahmedabad