10 Common Knee Problems – When to Worry and When to See a Doctor

10 Common Knee Problems – When to Worry and When to See a Doctor

Knee pain is a frequent reason for medical visits and can affect people of all ages, from athletes to older adults.

Whilst many common knee problems improve with rest and conservative treatment, some require specialist care to prevent long-term damage.

Understanding when to worry about knee pain and when to see a doctor is key to protecting knee function.

Below is a guide to 10 common knee conditions, their symptoms, warning signs, and when referral to orthopaedics may be needed.

1. Anterior Cruciate Ligament (ACL) Injuries

Symptoms: Knee instability, swelling, pain, and a popping sensation at the time of injury.

When to worry:

• Inability to bear weight
• Significant swelling
• Suspected associated injuries such as meniscal tears

When to see a doctor: Prompt medical assessment is needed. Patients are often referred to orthopaedics for imaging and discussion of surgical versus non-surgical treatment.

2. Meniscus Tears

Symptoms: Knee pain, swelling, locking, catching, or reduced range of motion.

When to worry:

• Persistent pain or swelling
• Knee locking or giving way
• No improvement with rest and physiotherapy

When to see a doctor: Initial management is usually conservative with NSAIDs and physiotherapy. Referral to orthopaedics is recommended if symptoms persist.

3. Patellofemoral Pain Syndrome (Runner’s Knee)

Symptoms: Pain around or behind the kneecap, worse with stairs, squatting, or prolonged sitting.

When to worry:

• Sudden severe pain
• Swelling or feelings of instability

When to see a doctor: Most cases respond to physiotherapy and activity modification. Orthopaedic referral may be required if symptoms fail to improve.

4. Knee Fractures

Symptoms: Severe pain, swelling, visible deformity, and inability to bear weight.

When to worry:

• High-impact trauma
• Open fractures
• Numbness, weakness, or poor circulation in the leg

When to see a doctor: Urgent assessment and referral to orthopaedics are required, often for surgical management.

5. Collateral Ligament Sprains (MCL or LCL)

Symptoms: Pain along the inner or outer side of the knee, swelling, and instability.

When to worry:

• Severe pain or instability
• Failure to improve with conservative treatment

When to see a doctor: Initial treatment includes NSAIDs, bracing, and physiotherapy. Referral to orthopaedics is appropriate if symptoms persist.

6. Knee Bursitis

Symptoms: Localised swelling, tenderness, warmth, and pain around the knee.

When to worry:

• Increasing redness or swelling
• Fever or signs of infection

When to see a doctor: Mild cases are managed conservatively. Persistent symptoms, suspected infection, or recurrent bursitis may require aspiration and orthopaedic referral.

7. Knee Tendinitis (Including Patellar Tendinitis)

Symptoms: Pain and swelling, typically worse with activity such as running or jumping.

When to worry:

• Persistent pain
• Reduced knee function despite rest

When to see a doctor: Conservative treatment with NSAIDs and physiotherapy is first-line. Referral to orthopaedics may be needed if pain does not improve.

8. Knee Osteoarthritis (OA)

Symptoms: Chronic knee pain, stiffness, reduced mobility, and swelling.

When to worry:

• Sudden worsening of pain
• Significant impact on daily activities

When to see a doctor: Management usually starts conservatively. Referral to orthopaedics may be appropriate for advanced disease or consideration of joint replacement surgery.

9. Iliotibial (IT) Band Syndrome

Symptoms: Pain on the outer side of the knee, especially during repetitive activities like running or cycling.

When to worry:

• Ongoing pain despite rest and physiotherapy
• Reduced mobility

When to see a doctor: Most cases improve with conservative care. Orthopaedic referral is considered if symptoms persist.

10. Knee Dislocation

Symptoms: Visible deformity, severe pain, swelling, and inability to move the knee.

When to worry:

• Numbness, weakness, or changes in skin colour
• Delay in reduction

When to see a doctor: This is a medical emergency. Immediate assessment and urgent orthopaedic involvement are required, often with surgery.

5 red flags for knee problems

1. Severe swelling or deformity — sudden or extreme swelling, visible deformity, or a displaced joint may indicate a fracture, dislocation, or ligament rupture.
2. Inability to bear weight — being unable to stand or walk on the affected leg signals a serious injury that needs urgent evaluation.
3. Sudden locking or instability — the knee catching, locking, or giving way could indicate a meniscus tear or ligament injury.
4. Signs of infection — redness, warmth, fever, or pus around the knee may suggest septic arthritis or infected bursitis.
5. Neurovascular compromise — numbness, tingling, pale or bluish skin, or weak pulses in the leg can indicate compromised blood flow or nerve injury.

Key Points on Knee Pain and Knee Injuries

• A detailed history and physical examination are essential when assessing knee problems.
• Imaging such as X-rays or MRI scans may be needed to confirm the diagnosis.
• Referral to orthopaedics is recommended for severe, persistent, or worsening knee symptoms.
• Early recognition and appropriate management of knee injuries can improve outcomes and reduce complications.

If knee pain is affecting your mobility, worsening over time, or associated with swelling, instability, or trauma, it’s important to seek medical advice promptly.