A bruised knee can be painful, and because this condition is typically the result of some type of stress or injury, it can occur with or without further knee injury. Sometimes referred to as a patellar contusion, it is the result of blood vessels beneath the surface of the skin being damaged and leaking blood. The signs of a bruise may range from discoloration on the surface of the skin to swelling and tenderness to the touch.
Normally, the bruising that occurs because of minor bumps or impact trauma is called subcutaneous bruising and is marked by mild to moderate discoloration of the area and possibly mild pain or tenderness upon touch. This type of bruising is usually acute, or temporary, and should heal itself and disappear within a few days. An injury like this that results from minor impact may hurt briefly, but it is normally not cause for alarm.
Periosteal and intramuscular bruising is typically more painful than a subcutaneous bruise and is the result of a more severe impact or trauma, such as what might occur with a sports injury. A bruise that occurs to the bone is called periosteal, while intramuscular bruising is bruising of the muscles. A bruised knee can result in one or both types of bruising, and while the tell-tale discoloration may be present, pain, swelling, and discomfort when moving and touching the knee is also a sign of injury.
Sometimes, a bruise on the knee is a secondary symptom of a more serious injury. Bruising can occur during dislocation and even fracture of the patella, or kneecap. An injury this serious would normally be evident by marked pain, discomfort, and swelling. Treatment for any painful knee injury should be sought and stress should not be placed on the injured joint until a medical professional has diagnosed the injury and provided instructions for treatment and recovery.
It is possible for other forms of stress besides impact or injury to cause a bruised knee. Stress can be placed on the knees by excess weight and previous knee injuries are susceptible to bruising, especially during the healing process. Regardless of the cause, the signs are usually present in the form of pain, tenderness, swelling, and discoloration. Ice is an good early form of treatment for reducing swelling and temporarily relieving pain. Individuals should avoid taking aspirin or anti-inflammatory drugs unless prescribed by a medical professional as these can increase blood flow. Knee injuries that cause pain with movement or immobility should be evaluated by a healthcare provider as soon as possible.
How To Heal a Bruised Knee
Bruised knees naturally heal on their own with time and rest, but certain activities can help them recover even faster. Many of those activities can be accomplished without a first aid kit or the help of a medical professional, so they can be completed immediately. Other treatments may require the use of first aid equipment or accessories.
Keep It Clean
Upon bruising your knee, the first thing to do is to clean the affected area without getting too much soap into the wound itself. Warm water and soap can remove any dirt, debris and bacteria that may cause trouble down the road. It will also be easier to treat the injury once it is free of skin irritants. Warm water can also relax the tissues around the area and relieve some initial pain.
An easy way to understand how to heal a bruised knee is to memorize RICE — for rest, ice, compress and elevate. The activities for RICE are outlined below:
- Rest: Keep the knee joint relaxed, making sure to refrain from using it if at all possible
- Ice: Apply ice or an ice pack wrapped in a towel to the affected area for 15-20 minutes per hour as needed
- Compress: Apply constant pressure to the bruised knee with a soft or elastic bandage
- Elevate: Raise the knee above heart level to prevent pooling blood
These steps can be used to treat bruised knees from any physical activity such as sports or hiking.
Pay Attention to It
Most minor knee bruises will go away on their own without the help of a medical professional, but it is a good idea to keep checking in on them. With each passing day, the pain should start to go away, the swelling should gradually subside and discolorations in the skin should heal. Check the injury regularly for signs of infection, such as pus, swelling and warmth.
Seek Medical Help
Although a bruised knee will normally heal on its own, sometimes the help of a medical professional may be required. See a doctor if the bruise persists beyond two to four weeks, starts to swell, shows excess red or purple patches, produces a sharp pain, or develops a large hematoma that does not decrease in size. Head to the emergency room if you feel painful swelling traveling to your arms, legs, feet or buttocks — that could be a rare condition called compartment syndrome.
The doctor will assess the injury with an X-ray, ultrasound, MRI or CT scan along with a physical examination. After an initial review, the doctor may provide crutches or a knee brace to protect the knee as it goes through the healing process. These protective medical accessories should be used until you are free of pain and swelling.
How Long Can a Bruised Knee Take To Heal?
Healing time for a bruised knee depends on the injury. Subcutaneous and intramuscular bruises will typically take two to four weeks to fully heal. Periosteal bruises may take one to two months to heal for smaller injuries or several months for larger ones. Using the hurt knee may extend the duration of the injury and, thus, the healing time.
What To Put on a Bruised Knee
Before placing anything on the bruised knee, it is best to clean the area with warm soap and water to remove irritants. You can apply ice for 15-20 minutes every hour to reduce swelling and help the area heal faster. A soft or elastic bandage can be wrapped around the area to prevent excessive swelling and further injury.