The knees are vulnerable to injury. From walking to running, the knee joints take a lot of strain.

The most common causes of short-lived or chronic knee pain are:

• Anterior Cruciate Ligament (ACL) tear – common in athletes or people who play sports
• Meniscus cartilage tear – often happens if you twist the knee suddenly while you’re putting weight on it
• Tissue inflammation
• Patellar tendinitis – irritation of a tendon around the knee joint
• Minor joint fractures
• Dislocation
• Iliotibial band syndrome – common in cyclists and distance runners

Less common causes of knee pain include:

• Gout
• Infection around the knee joint
• Osteoarthritis
• Rheumatoid arthritis
• Obesity, which places chronic extra stress on the joints
• A loose body, which is when a bone or cartilage fragment breaks away and causes discomfort in the joint space

You don’t always need to see a doctor for knee pain; however, an ultrasound is nevertheless still the best way to diagnose your condition.

You should visit your doctor and consider an ultrasound scan if you have:

• Stiff knee
• Restricted knee movement
• Knee swelling
• Weak knee
• Chronic knee pain
• Knee joint pain

Visit your doctor promptly if you’re experiencing any of the following:

• Red knee
• Knee pain following an injury or accident
• Significant knee swelling
• Knee warm to the touch
• Knee popping or knee crunching
• Unable to straighten the knee
• Severe pain around the joint

These symptoms may suggest an infection, dislocation, or fracture around the knee joint, and you shouldn’t ignore them.

If your knee pain is mild, self-care at home may be enough. However, you should always visit your doctor if it doesn’t clear up with rest after a few weeks.

There’s very little preparation required for a knee ultrasound.

What we do recommend is that you wear loose, comfortable clothing as you may need to remove it for the scan.

First, you’ll be asked to lie or sit on the examination table and expose your knee.

The specialist places a small quantity of clear, water-based gel around your knee area.

This is painless, although it may feel cold at first. The gel acts as a lubricant so the ultrasound probe glides over your skin without causing discomfort.

Once you’re ready, the specialist places the ultrasound probe against your skin.

They move the probe around the area, capturing images of your knee area as they go.

Once they’ve captured enough images to make a diagnosis, the scan is complete. You can then relax and remove the gel and get changed if necessary.

After the scan, the specialist reviews the images and provides a diagnosis if possible. If a diagnosis isn’t possible at this stage, further investigations will be recommended.

There’s no aftercare required following an ultrasound scan. You can go home immediately and resume your daily activities.