Common causes of knee joint pain may include overuse, arthritis, and injury. A person may manage symptoms with anti-inflammatory medications or adopt some lifestyle changes, such as maintaining a moderate weight to reduce stress on knees or doing certain low impact exercises.
Depending on the cause of knee joint pain, the levels of pain range from mild to severe. Pain may also be acute (short-term) or chronic (long lasting). Treatments usually help manage pain and prevent it from worsening.
Read on to learn more about the causes, symptoms, and treatments for knee joint pain.
Knee pain occurs on or around the joint. Knee joint pain may happen when a person:
- bends their leg
- puts weight on it
- performs certain activities, such as walking down stairs
The knee is the biggest joint in the body, according to the Arthritis Foundation. It connects the bones of the upper and lower leg. It acts as a hinge during movements such as sitting, squatting, and walking.
Symptoms
Symptoms of knee joint pain include limited mobility that makes it hard to bend or straighten the leg.
Ligament injuries may result in instability and weakness, causing the knee to give way. The knee may lock, catch, or buckle.
Additional symptoms that may occur include:
- swelling
- stiffness
- redness
- bruising
- warmth
According to the American Academy of Orthopaedic Surgeons, common knee conditions that may cause the above symptoms to occur include:
- Osteoarthritis (OA): Due to aging or an injury, the articular cartilage that lines the joints gradually wears away. As a result, the bones rub against each other, causing pain and stiffness.
- Chondral defect: Damage may occur in a single location of the articular cartilage, though the rest of the joint may be healthy.
- Anterior cruciate ligament (ACL) injury: An ACL tear may occur due to a sudden directional change or improperly landing a jump.
- Posterior cruciate ligament (PCL) injury: A direct blow to the front of a bent knee can cause a PCL injury. Often this occurs during an athletic activity or car collision.
- Meniscal injury: Arthritis, aging, and movements such as twists, pivots, or squats can lead to meniscal tears.
- Collateral ligament injury: A direct blow to the inside of the knee or quick twisting movement can lead to a torn or overstretched collateral ligament.
Several factors increase the risk of knee joint pain, including age, overuse, and trauma.
Often, knee injuries relate to sports and professions that require repetitive movements. According to a 2022 research review, the following activities may increase the risk of pain and of a person developing OA in the knee:
- heavy lifting
- squatting
- knee bending
- kneeling
- climbing
Research from 2002 explored other possible risk factors for knee joint pain, such as:
- body mass
- lifestyle factors, such as stress and smoking
- frequency of exercise
- daily lifting of loads
- work-related factors, such as time spent sitting in the seated position
Other common causes of knee pain include medical conditions such as:
- bursitis, a fluid-filled sac that becomes inflamed
- bleeding in the joint
- gout
- Osgood-Schlatter’s disease, which is inflammation of the area just below the knee
- Baker’s cyst, swelling in the space between the knee
- Osteochondritis dissecans, which is when a fragment of the bone separates from the knee
Other causes may include injuries and overuse, such as:
- torn ligament, tendon, or meniscus, as well as cartilage damage
- kneecap dislocation
- sprain or strain
- referred pain, meaning the pain comes from another source
To prevent short-term pain from becoming chronic, a person should reach out to a healthcare professional if their knee pain does not improve or worsens within a few weeks, the U.K. National Health Service suggests.
They should contact a doctor if the knee locks, painfully clicks, or gives way.
A person should also contact a doctor if they experience any of the following:
- they cannot move the knee or put any weight on it
- they have unexplained weight loss
- they experience pain at night or rest
- they have a swollen or warm knee
It is important to receive a diagnosis to determine the appropriate treatment options and prevent worsening symptoms or complications.
A doctor will thoroughly examine the knee to assess whether the pain stems from the knee. Sometimes knee pain may result from pain from another source, such as a hip injury.
When making a diagnosis, a doctor will consider information such as:
- Patient characteristics: Some conditions are more likely to occur in people who meet certain risk factors. For example, OA is more common in older adults, and overuse and trauma may be more frequent in sportspeople and athletes. Obesity may also be a factor in some conditions.
- Medical history: Doctors may ask questions about where and when a person feels pain and determine potential sources of trauma
- Results of an examination: A medical professional moves the knee to check for signs of damage to the muscle, tendon, or cartilage. This also includes exploring the location of the pain.
- Imaging and other tests: X-rays, MRI scans, ultrasounds to assess joint bursa, or other diagnostic tests can help identify structural damage or atypical structures.
The specific cause and symptoms accompanying the pain will help determine the best line of treatment. A range of treatment options are available, including:
- Pain relievers: These medications include over-the-counter (OTC) remedies for pain relief, such as acetaminophen and nonsteroidal anti-inflammatory drugs.
- Lifestyle changes: A person can make certain lifestyle changes, such as maintaining a moderate body weight, that will help lessen knee stress.
- Exercise: Certain exercises may help build or stretch muscles and ease knee pain. A person can work with a physical therapist to target specific areas and learn which exercises to avoid, such as running, because they exert too much force on the knees.
- RICE (rest, ice, compression, and elevation): This can help with acute knee pain, but for chronic pain, rest may weaken muscles that need strengthening to reduce the pain.
- Alternative treatments: Some people may also find pain relief using alternative remedies such as:
If knee pain and function do not improve, it may mean a person needs surgery. Doctors mainly use these procedures to fix structural damage. Surgery will not be the first option in most cases.
Other treatment options may also include regenerative therapies. These therapies may include plasma injections and stem cell treatments. However, research continues in this area because their effectiveness for knee pain is not yet conclusive.
The causes, management, and treatment of knee pain are similar to other joint pain in the body, including the:
- shoulder
- elbow
- hip
- ankle
Certain medical causes of knee joint pain can affect other areas of the body. Management and treatment options will depend on the causes and severity of the symptoms.
Knee pain is relatively common, often resulting from excessive use, an injury, or a chronic condition.
In most cases, it is possible to ease knee pain and prevent it from worsening with home remedies and OTC treatments. A person should seek medical attention if their pain is severe or does not respond to treatment.