Knee pain is one of the most common joint complaints, affecting people of all ages. It can result from injuries, overuse, or chronic conditions like arthritis. Whether it’s a dull ache, sharp pain, or stiffness, knee pain can limit movement and affect your quality of life. Understanding what’s causing your knee pain is key to finding effective relief and preventing long-term damage.

Understanding The Knee Joint

The knee is a complex hinge joint that supports your body weight and allows movement such as walking, running, and sitting.
It consists of several parts that can each be a source of pain:

  • Bones: The femur (thighbone), tibia (shinbone), and patella (kneecap).

  • Ligaments: The ACL (anterior cruciate ligament) and PCL (posterior cruciate ligament) stabilize motion.

  • Meniscus: Two C-shaped cartilage cushions that absorb shock.

  • Tendons: Connect muscles to bone and help you extend or bend your knee.

  • Synovial membrane: Produces fluid that lubricates and protects the joint.

When any of these structures are strained, inflamed, or damaged, knee pain develops—often accompanied by swelling, stiffness, or difficulty moving.

Common Symptoms

Knee pain can vary in intensity and location. You may experience:

  • Swelling or redness

  • Stiffness or reduced range of motion

  • Popping, grinding, or clicking sounds

  • Weakness or instability

  • Pain when walking, bending, or climbing stairs

These symptoms often point to specific causes, from ligament damage to inflammation or cartilage wear.

Potential Causes Of Knee Pain

Knee pain can result from several causes—ranging from sudden injury to gradual wear and tear over time.

1. Injury

Sudden trauma from sports, falls, or accidents can damage ligaments, tendons, or cartilage.
Common injuries include:

  • ACL tear: Often caused by a sudden twist or landing improperly after a jump.

  • Meniscus tear: Occurs when rotating the knee while bearing weight.

  • Fractures: The kneecap or bones around the joint can break after impact.

  • Dislocation: When bones in the knee move out of alignment.

Injury-related pain can appear suddenly and may be accompanied by swelling, bruising, or limited movement.

2. Overuse

Repetitive movements—especially from running, cycling, or kneeling—can stress the joint over time.
Common overuse conditions include:

  • Runner’s knee (chondromalacia): Pain at the front of the knee due to cartilage wear.

  • Patellofemoral pain: Dull aching behind or around the kneecap, often worse when climbing stairs or sitting for long periods.

Overuse pain tends to develop gradually and worsen with activity.

3. Bursitis

The bursa is a fluid-filled sac that cushions the joint. Repeated pressure, injury, or infection can cause bursitis, leading to:

  • Swelling or warmth in the knee

  • Pain during movement or rest

  • Tenderness when pressing around the joint

Bursitis pain often spreads and may worsen with kneeling or bending.

4. Tendinitis

Tendinitis occurs when tendons become inflamed, usually due to overuse or aging.

  • Patellar tendinitis (jumper’s knee) causes pain at the front of the knee, especially during jumping or running.

  • Pain may worsen at night or after prolonged sitting.

5. Arthritis

Arthritis is one of the leading chronic causes of knee pain. The two most common types are:

  • Osteoarthritis: Caused by cartilage wear and tear, often linked to aging or repetitive use. The pain is diffuse and typically worse in the morning.

  • Rheumatoid arthritis (RA): An autoimmune disorder that attacks joint linings, causing swelling, stiffness, and pain on both sides of the body.

Both types can cause chronic inflammation, leading to joint deformity if untreated.

6. Baker’s Cyst

A Baker’s cyst is a fluid-filled lump behind the knee caused by excess synovial fluid. It may lead to:

  • Tightness or stiffness

  • A visible swelling at the back of the knee

  • Pain if the cyst ruptures

This condition often occurs alongside arthritis or meniscus tears.

7. Iliotibial Band Syndrome

This overuse condition affects runners and cyclists. The iliotibial (IT) band, a long strip of tissue from the hip to the knee, becomes irritated—causing pain on the outer side of the knee, especially when bending.

8. Infection

Septic arthritis is a bacterial infection inside the knee joint.
Symptoms include:

  • Severe pain

  • Swelling and redness

  • Fever or warmth around the knee

This condition requires immediate medical attention.

Risk Factors

Certain factors make knee pain more likely, including:

  • Age: Joint wear increases over time.

  • Obesity: Extra weight adds pressure to the knees.

  • Gender: Women are more prone to knee arthritis.

  • Past injuries: Increases risk of chronic pain.

  • Physical inactivity: Weak muscles strain the joint.

  • High-impact sports: Running, football, or basketball increase risk.

  • Genetics: Family history of joint issues.

  • Occupation: Jobs involving frequent squatting or lifting.

When To See A Doctor

You should contact a healthcare provider if you experience:

  • Inability to bear weight

  • Severe or sudden pain

  • Swelling or deformity

  • Warmth or redness with fever

  • Clicking, locking, or buckling

  • Persistent pain lasting more than three days

Immediate care is needed if the pain follows trauma or injury.

Diagnosis

A healthcare provider may:

  • Examine your knee for tenderness, swelling, and stability

  • Check range of motion and muscle strength

  • Order X-rays, CT, or MRI scans to detect fractures or soft tissue damage

  • Perform joint fluid tests to check for infection or gout

Treatment Options

Treatment depends on the cause and severity of your pain.

RICE method: Rest, Ice, Compression, and Elevation can reduce pain and swelling after injury.

Pain medication: Over-the-counter drugs like ibuprofen or acetaminophen help manage discomfort.

Physical therapy: Strengthening and stretching exercises can restore function and stability.

Lifestyle changes: Maintain a healthy weight, use proper footwear, and avoid high-impact activities.

Complementary therapies: Yoga, acupuncture, and massage may help relieve chronic pain.

Genicular nerve block: A numbing injection that temporarily stops pain signals.

Surgery: Reserved for severe cases like ligament tears or joint damage when conservative treatments fail.

Prevention

Keep your knees strong and flexible with these steps:

  • Exercise regularly but focus on low-impact activities like swimming or cycling.

  • Warm up before workouts and stretch afterward.

  • Wear supportive shoes to maintain proper alignment.

  • Avoid overtraining and allow recovery time.

  • Maintain a healthy body weight to reduce stress on your knees.

Living With Knee Pain

Chronic knee pain can make daily tasks challenging, but adopting healthy habits can help manage symptoms:

  • Manage stress and get enough rest.

  • Maintain a balanced diet for joint health.

  • Use supportive aids like braces or canes if necessary.

  • Try mind-body practices such as tai chi or meditation for relaxation and pain control.