Why Does My Knee Hurt? The 7 Most Common Causes of Knee Pain

Knee pain is one of the most common reasons people visit an orthopaedic clinic. It can affect anyone — from teenagers who play sports to adults with physically demanding jobs, and older individuals experiencing wear and tear in their joints.

The knee is a complex joint made up of bones, cartilage, ligaments, tendons, and muscles. When any of these structures become injured or irritated, pain can develop.

Understanding what may be causing your knee pain is the first step toward finding the right treatment.

In this article, we will explore the seven most common causes of knee pain, the symptoms to watch for, and when it may be time to seek specialist care.

1. Osteoarthritis (Wear and Tear Arthritis)

Osteoarthritis is the most common cause of knee pain in adults over 50.

It occurs when the cartilage that cushions the bones gradually wears away. Without this protective layer, the bones begin to rub against each other, causing pain and stiffness.

Common symptoms

• Pain that worsens with walking or climbing stairs
• Morning stiffness
• Swelling around the knee
• Reduced range of motion

2. Meniscus Tears

The meniscus is a C-shaped cartilage that acts as a shock absorber between the thigh bone and shin bone.

A tear can occur during sports, sudden twisting movements, or even simple activities in middle age when the cartilage becomes weaker.

Symptoms

• Pain when twisting or squatting
• Locking or catching sensation in the knee
• Swelling
• Difficulty fully straightening the knee

3. Ligament Injuries

Ligaments stabilize the knee. The most well-known is the Anterior Cruciate Ligament (ACL).

Ligament injuries commonly occur in sports that involve sudden stops, pivoting, or jumping.

Symptoms

• Sudden pain after an injury
• A “popping” sensation
• Knee instability
• Swelling within hours

4. Patellofemoral Pain Syndrome (Runner’s Knee)

This condition causes pain at the front of the knee around the kneecap.

It is common in:

• runners
• cyclists
• people who sit for long periods
• teenagers and young adults

Symptoms

• Pain when climbing stairs
• Pain after prolonged sitting
• Grinding sensation around the kneecap

5. Tendinitis (Inflammation of Tendons)

Tendons connect muscles to bones. Repetitive stress can lead to inflammation.

Common examples include:

• Patellar tendinitis (jumper’s knee)
• Quadriceps tendinitis

Symptoms

• Pain just below or above the kneecap
• Pain during physical activity
• Tenderness over the tendon

6. Bursitis

Bursae are small fluid-filled sacs that reduce friction in the knee. These sacs can become irritated and inflamed. When this happens, it can cause pain

Inflammation of these sacs can occur due to:

• repetitive kneeling
• injury
• infection

Symptoms

• swelling at the front of the knee
• warmth around the joint
• pain with pressure

7. Referred Pain from the Hip or Spine

Sometimes the knee itself is not the problem.

Conditions affecting the hip joint or lower back can cause pain that is felt in the knee.

This is why a careful assessment by a specialist is important to ensure the correct diagnosis.

When Should You See a Specialist for Knee Pain?

You should consider seeing an orthopaedic specialist if:

• knee pain lasts more than 2–3 weeks
• the knee feels unstable or gives way
• swelling keeps returning
• the knee locks or cannot fully straighten
• pain is limiting your daily activities

Early evaluation can often prevent small problems from becoming larger ones.

A Patient-Centred Approach to Knee Pain

Every patient’s situation is different.

The most effective treatment begins with listening to your symptoms, understanding your lifestyle, and identifying what matters most to you — whether that is walking without pain, returning to sports, or staying active with your family.

Modern orthopaedic care focuses on:

• accurate diagnosis
• conservative treatment whenever possible
• evidence-based surgical options when necessary
• supporting patients throughout recovery

Book an Appointment

If knee pain is affecting your daily life, an early assessment can help identify the cause of your pain and guide you toward the most appropriate treatment.

Book a consultation today to discuss your symptoms and explore the options available to help you move comfortably again.