The medical term for a bruise is a contusion. Injuries to bones, muscles, and the tissue just under the skin can cause bruises. The eyes and mouth, as well as internal organs such as the lungs, can also bruise.
Bruises are a type of bleeding under the skin. A sharp blow, such as from falling or colliding with a large object, can break tiny blood vessels called capillaries. This causes bleeding in the area of the injury.
Because the bleeding is under the skin, the area may swell and look red or blue. The bones and soft tissue can bruise. Some types of contusion include:
A subcutaneous contusion is a bruise just beneath the skin. It is the type of bruise that most people are familiar with. Almost everyone experiences a subcutaneous contusion at some point.
Just as a cut bleeds from tiny blood vessels, injuries to tiny blood vessels under the skin cause most subcutaneous contusions. Areas that a person may land on or use to support themselves during a fall, such as the hands and knees, are particularly vulnerable.
Very rarely, a large bruise causes massive bleeding, from a vein or artery, that is difficult to stop. This can be life-threatening without treatment. These contusions are large and extremely painful, and they are usually due to major trauma, such as a serious car accident.
A small bruise on a person’s knee or elbow will not cause them to bleed to death without some other condition, such as a bleeding disorder, being present.
The muscles are full of blood vessels that supply them with blood and oxygen. A bruise to a muscle is deeper than a subcutaneous contusion, and it can be very painful. A person with a muscle contusion may think that they have a sprain, strain, or broken bone.
Muscle contusions often heal without treatment. Sometimes, however, a large volume of blood will collect in the muscle. This can cause a painful swelling called a hematoma. Doctors may drain a hematoma to help the muscle heal more quickly.
A bone contusion can feel similar to a break or fracture, and it may make it difficult to move the area of the injury. For example, a rib contusion can make breathing difficult and painful.
Bones are complex body parts, with hard tissue on the outside and soft bone marrow on the inside. Any area of the bone can bruise. Damage to the hard, calcium-rich bone structure causes tiny breaks in the bone.
Bone contusions can cause a number of complications, including a condition called osteochondritis dissecans. This happens when a small piece of bone separates from the rest of the bone. This often happens when a bruise interferes with blood supply.
Osteochondritis dissecans commonly occurs in joints such as the knee or ankle.
Cartilage is flexible but thick tissue that is harder than muscle but softer than bone. The outside of the ears and the tip of the nose both contain cartilage.
Bruises to cartilage can occur when the cartilage bends, or when something sharply hits the cartilage.
Most cartilage injuries are not serious and will heal without treatment.
Internal organs such as the kidneys, lungs, and heart can develop bruises after a forceful blow or fall. Organ contusions damage the blood vessels and other soft tissue in organs.
These injuries are dangerous, and they can be life-threatening. This is because they may interfere with the functioning of the organ. People with organ contusions may require hospitalization.
For example, a person with a pulmonary contusion, or a bruise on the lungs, may need to use an artificial ventilator.
An eye contusion is a bruise on or around the eye. Contusions on the eyelid can be painful and may look swollen. However, they are rarely serious.
A person may also bruise the cornea, which is the tissue inside the eye. This can be more serious, especially without treatment or if there are other eye injuries present.
For most contusions, the main symptom is pain. The pain can be either mild or severe.
Larger, deeper contusions, such as those affecting the bone or muscles, are typically more painful. If there is pain following a fall or blow, there may be a contusion.
Some common symptoms of a contusion include:
- red, blue, or black swelling near the injured area
- throbbing or aching
- difficulty moving the area
Contusions to organs can affect their ability to function. Following a hard blow to the stomach, back, or chest, a person should seek immediate medical treatment for pain, swelling, weakness, or any signs of illness. These could be signs of an organ contusion.
Difficulty breathing or changes in heart rate could be signs of a lung or heart contusion. These are medical emergencies that require immediate treatment.
Most contusions of bones, muscles, skin, and cartilage will not need medical treatment. Instead, using the RICE method at home can help with pain and swelling, as well as speed up recovery:
- R: Rest the injured area. Avoid playing sports, exercising, or stretching unless a doctor has suggested otherwise. Sometimes, they may suggest immobilizing the injured area with a splint or wrap. Consider taking time off of work or school if the injury is very painful.
- I: Ice can help with swelling and pain. Try applying an ice pack to the area for 20 minutes at a time, with a 20-minute break between each ice pack session.
- C: Compress the area to reduce swelling and pain. To do this, gently wrap it in a bandage or wrap. The wrap should not be painful, cause numbness, or leave deep marks in the skin.
- E: Elevate the area above the heart. This can help with swelling and pain. A few pillows piled on a bed can work well.
Organ contusions may require more intensive treatment, including hospitalization. A doctor may need to perform surgery to repair an injury or stop the bleeding. Continuous monitoring of vital signs may also be helpful, especially following a kidney or lung contusion.
A person should see their doctor following a serious traumatic incident such as a car accident, a fight, or a fall from an extreme height. This is especially important to do if the pain is intense or the injury does not go away on its own within a few days.
A contusion is an injury that causes bleeding and tissue damage underneath the skin, usually without breaking the skin. Any injury that puts pressure on an area repetitively can cause a contusion.
Falls, blows sustained during fights or from falling objects, and car accidents may also cause bruises.
Contusions can be very painful, even when they are not serious. Pain is a message from the body that urges rest and care. With rest, most contusions will heal within a few days. Very large contusions, however, may take several weeks to heal.