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Bruises on my legs
Last reviewed: 05.07.2025

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You fell off your bike, hit your shin on a coffee table, and suddenly saw a nasty blue bruise spreading across your leg. What causes bruises on your legs, how to deal with them, and how to avoid them?
What are some less common causes of bruising and what do they indicate?
The terms used to describe the different types of bruises often refer not only to their appearance but also to their causes. Petechiae refer to 1-3 millimeter collections of blood under the skin. They can appear as a few small red spots anywhere on the body (most commonly on the legs). More often than not, there are several of these spots, and they can be a clue that there is a serious health problem. Examples include infection of the heart valves (endocarditis) or impaired blood clotting due to malfunctioning elements (platelets).
Bruises around the navel may be caused by bleeding in the abdominal cavity. A bruise behind the ear (a sign of trauma) may indicate that destructive changes are occurring in the skull.
Finally, bruises that occur in a complex, that is, several at once, and occur without trauma, can be a sign of various types of autoimmune diseases (diseases in which the body attacks its own blood vessels). Each of these conditions should be assessed and analyzed by a doctor.
The nature of bruises on the legs
A bruise on the legs, like any other bruise on the body, occurs when tiny blood vessels are damaged or compressed by a blow to the skin (either bumping into something or from a blow to soft tissue). The blow or bruise is caused by blood leaking from these vessels into the damaged tissues, as well as the body's response to the injury.
A bruise is a medical term for a contusion. A bruise becomes purple when blood leaks from the upper layers of the skin, a fresh hematoma is called a bruise.
Why do some people bruise more often than others?
Injuries that cause bruises affect people differently as they age. Bruising occurs more easily in older people. It may take a lot of effort to cause bruises in a small child, but even minor bumps and scrapes in the skin can cause extensive bruising in an older person. The blood vessels of older people become more fragile as people age, and bruises can occur in older people even without injury.
Medicines are to blame
The amount of bruising may also be affected by medications that prevent blood from clotting (and cause more bleeding into the skin or under the tissue). These medications include many arthritis medications called nonsteroidal anti-inflammatory drugs (such as ibuprofen [Advil, Nuprin] and naproxen [Aleve]) and over-the-counter medications such as aspirin and warfarin (Coumadin).
They are often prescribed by doctors specifically to prevent blood clotting in patients who have been diagnosed with blood clots in the legs or on their way to the heart. Warfarin can cause severe bruising of the legs, especially if drug levels become too high. Cortisone drugs, such as prednisone, promote bruising of the legs by increasing the fragility of the tiny blood vessels under the skin.
Patients with inherited bleeding problems (such as hemophilia) or acquired bleeding disorders (such as those with liver diseases such as cirrhosis) may develop extensive bruising, contusions, unexplained bleeding, and even life-threatening bleeding. What are the symptoms and signs of a bruise, and why does a bruise change color?
Bruises can be caused by the fragility of the blood vessels in the areas of the body that change color. Bruises can change color over time, and you can tell how old they are by looking at them. At first, the bruise will have a reddish appearance, reflecting the color of the blood under the skin. After one or two days, the blood vessels change, and the bruise will look blue or purple. On the sixth day, the color of the bruise changes to green, and after eight to nine days, the bruise will turn yellow-brown. In general, the bruise will go away within two to three weeks, after which the skin will return to normal.
The crimson color of the bruise is due to blood spilled under the skin, burst vessels. The place of this bruise begins to be surrounded by so-called protective cells - leukocytes, they destroy the blood that has caked, thanks to this it is excreted from the body. When blood cells are destroyed, a greenish substance is formed - biliverdin, and another yellow substance - bilirubin. That is why the bruise changes color to green and yellow.
What happens when a bruise doesn't go away?
In some cases, instead of fading, the bruised area on your leg becomes hard and may increase in size. That area of your leg may also continue to hurt. There are two main reasons for this. First, if a large amount of blood gets under the skin or into the muscle, instead of clearing the painful area of blood, the body may wall it off and cause what is called a hematoma. A hematoma is nothing more than a small pool of blood that has pooled under the skin. Ice the affected area and the hematoma will soon go away.
But sometimes a situation arises when there is so much calcium in the body that it forms deposits in the area of the injury on the leg. This area becomes vulnerable and elastic, painful. This process is called heterotopic ossification or myositis (inflammation of the muscles around the bones). This condition is diagnosed by X-ray and requires a trip to the doctor.
How to treat bruises on the legs?
There are a few things you can do to prevent or minimize bruising after an injury. First, try a cold compress. Put ice in a plastic bag, wrap the bag in a towel (applying ice directly to the skin can cause frostbite), and place it on the injured area. Commercial ice packs are readily available, but ice from the freezer is a great substitute.
Ice is first applied to the injured area and can be re-frozen and reused (but don't eat it!). The cold compress reduces blood flow to the area and therefore limits bleeding under the skin, reducing the size of the bruise.
Cold also reduces inflammation in the area of injury and within the edema. If possible, elevate the injured leg above the level of the heart. The higher the heart is in relation to the lower extremities, the more blood will flow to the leg area and increase bleeding and swelling.
Avoid medications that may promote bruising. If you have questions about medications that may promote bruising, talk to your doctor or pharmacist. Do not stop taking prescription medications without first talking to your doctor. Finally, applying pressure to the bruised area (with your hands) may reduce bleeding.
People who take medications that reduce blood clotting ("blood thinners") or for a clotting disorder should seek medical advice if they develop a bruise on their leg, and older people or those who have experienced severe trauma should especially seek medical advice.
Leg Blows and Bruises - Useful Facts
A bruise on the leg is medically called a contusion.
Bruises on the legs occur when tiny blood vessels are damaged or broken.
The injuries that cause a bruise on the leg vary depending on age and the use of certain medications.
Bruises on the legs can change appearance over time.
Spontaneous bruising on the legs without trauma may indicate serious bleeding disorders.