The skin is the body’s largest and primary protective organ, covering its entire external surface and serving as a first-order physical barrier against the environment. Its functions include temperature regulation and protection against ultraviolet (UV) light, trauma, pathogens, microorganisms, and toxins. A bruise generally occurs when there is some kind of trauma to the skin. Trauma to the skin ranges from relatively mild trauma like slightly brushing against an object to severe trauma like hard, forceful blows on any part of the body. The resulting effect of these processes on the skin results in a bruise. Usually in bruises, the skin is not damaged or it will be a cut and no longer a bruise. Apart from trauma or injuries, other things that can cause bruising include viral infection or illness affecting blood clotting, low platelets (the component of blood responsible for blood clotting, liver disease, leukaemia, medical treatment, including radiation and chemotherapy, medications that interfere with blood clotting like warfarin, or heparin.
Everybody must have experienced bruises at one time or another in their lives. It is therefore important to understand what happens to the body when a bruise occurs.
What happens in a bruise?
The skin is primarily made up of three layers. The upper layer is the epidermis, the layer below the epidermis is the dermis, and the third and deepest layer is the subcutaneous tissue. It has a very rich supply of blood vessels. These blood vessels are often thin walled and form interconnections (or plexuses) derived from an extensive network of larger blood vessels that extend from branches of the bigger blood vessels. When there is a bruise, these blood vessels are easily broken and they cause bleeding under the skin.
Three criteria must be met to create a bruise. The first criterion is that the force acting on the skin should be enough to cause blood vessels to rupture in it, but not to disrupt the integrity of the skin. The pressure of force is usually transmitted by a blunt object. Otherwise the skin would be damaged. The second criterion is the blood pressure, which should be high enough to allow seeping of the blood in the connective tissue of the skin. The third criterion is the location of the field of bleeding. The blood should seep out into the skin sufficiently close to the surface of the skin to be detected as a bruise. The bleeding into the skin can occur from broken blood vessels that form tiny red dots (called petechiae). The blood can also collect under the skin in larger flat areas (called purpura), or in a very large bruised area (called an ecchymosis).
How does a bruise heal?
As soon as the blood vessels under the skin are broken and a bruise is formed, the body immediately begins the process of healing. The blood seeping under the skin promptly clots to limit more bleeding, while the inflammatory reaction also starts at the same time. this is why bruises usually is associated with some form of edema or swelling of the area. Next, special cells are produced to ‘break down’ the blood clot under the skin into tiny fragments which are reabsorbed back by the body.
As soon as a bruise is formed, the blood under the skin makes it have a reddish color. Within hours, it will turn into a dark blue or purple color. As the bruise begins to heal it changes colors. The color change is due to the biochemical breakdown of hemoglobin that is found in the blood. As the different components of the blood are broken down, different colors will appear in the bruise. This color change will continue to occur until it gradually clears off and the skin returns to normal. This usually takes about 2 weeks to completely clear off.
What are the color changes noticed as a bruise heals?
The skin color affects the appearance of a bruise. People with medium skin tones have brighter bruises generally the people with darker skin tones.
The color changes that occur as a bruise heals are:
- Red because of the fresh, hemoglobin-rich blood which has newly pooled underneath the skin.
- After around 1–2 days, it appears blue, purple, or black because of breakdown of hemoglobin.
- In about 5–10 days, it changes to yellow or green color. These colors are as a result of substances called biliverdin and bilirubin which are produced when the body breaks down hemoglobin.
- In 10–14 days, it will turn to a shade of yellowish-brown or light brown.
- After it turns light brown, it will begin to fade.
- Most bruises in healthy people will disappear without treatment after this stage.
What happens when there is a bruise with white center?
Bruises heal differently for different people. The clearance of the hemoglobin in the blood can occur in any order. A bruise may clear in the center before the outer edge. This will result in a white or brownish center surrounded by the fading colors of the healing bruise. It is part of the healing process and is not usually a sign to be worried about. Within 2 weeks, the whole bruise will have cleared up.
How to make a bruise heal faster?
There is usually no need to see a doctor for a bruise. Simple home remedies can make it heal faster or reduce the pain and discomfort associated with bruises. They are.
Rest and elevate the injured area to prevent swelling and relieve pain.
Apply ice packs for the first 24 to 48 hours after injury. Wrap the ice pack in a towel and apply ice for no more than 15 minutes at a time. Repeat throughout the day.
Apply a heating pad or warm compress to the injured area after two days. You can apply heat several times throughout the day.
Take over-the-counter pain medication, such as acetaminophen.
When do you see a doctor for a bruise?
While there is no need to see a doctor for a bruise, it is advisable to visit a doctor in some situations like.
A bruise accompanied by swelling and extreme pain especially taking a blood-thinning medication for a medical condition.
Bruising that occurs easily or for no apparent reason.
A painful bruise under a toenail or fingernail.
A bruise that does not improve within two weeks or fails to completely clear after three or four weeks.
Suspicion of a broken bone along with the bruise.
Severe bruises in some special areas like on the head or the eye.