Why Do Knees Crack or Pop? Doctor Explains

by | Apr 15, 2025

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Do your knees crack or pop when you stand, squat, or climb stairs? Many people experience this, but is it a cause for concern? Dr. Siddharth Tambar from Chicago Arthritis and Regenerative Medicine breaks down the causes, common myths, and when to seek medical attention.

What Causes Knee Cracking or Popping?

Knee noises, also called crepitus, happen for several reasons:

1. Gas Bubbles

Just like cracking your knuckles, gas bubbles in the knee joint can form and collapse, creating a popping sound. This is harmless and completely normal.

2. Tendon or Ligament Movement

Tendons and ligaments around the knee can shift slightly over bones, creating a snapping sensation. If there is no pain, it is not a concern.

3. Cartilage Changes

Over time, the smooth cartilage in your knee may wear down, leading to rough surfaces that create crackling noises. This can be a normal part of aging, but if pain is present, it may indicate a problem.

4. Meniscus Tears or Loose Cartilage

If your knee suddenly starts locking, catching, or popping with pain, a torn meniscus or loose cartilage may be the cause. This may require medical attention to prevent further damage.

5. Arthritis and Inflammation

Osteoarthritis and inflammatory arthritis can cause rough joint surfaces and excess fluid, leading to more noticeable popping and discomfort. Early diagnosis can help manage symptoms.

When Should You Be Concerned?

While knee cracking is often harmless, see a specialist if you experience:

  • Pain with popping – Could indicate an injury or arthritis
  • Swelling or stiffness – May suggest inflammation or damage
  • Locking or instability – Could be a meniscus tear or ligament issue
  • Sudden cracking after an injury – A loud pop followed by pain may signal a ligament tear, like an ACL injury

If any of these symptoms occur, seek medical attention to prevent long-term damage.

How to Keep Your Knees Healthy

Good knee health can reduce unnecessary cracking and discomfort. Here is what you can do:

  • Strengthen Leg Muscles – Strong quads and hamstrings help support knee stability
  • Improve Flexibility – Stretching and mobility work prevent tendons from snapping over bones
  • Eat an Anti-Inflammatory Diet – Leafy greens, fatty fish, and turmeric support joint health
  • Stay Active, But Avoid Overuse – Low-impact activities like cycling, swimming, and walking protect the knees
  • Maintain a Healthy Weight – Reduces stress on knee joints, preventing premature wear and tear

Common Myths About Knee Cracking

  • “If my knee cracks, I must have arthritis.”
    Not true. Cracking can happen in healthy joints. Arthritis is diagnosed based on pain, swelling, and stiffness, not just noise.

  • “Cracking my knees will cause joint damage.”
    There is no evidence that harmless cracking leads to long-term damage. Pain or instability is a different story.

  • “Only older people have knee cracking.”
    Knee popping can happen at any age, even in young athletes or kids due to ligament movement or minor imbalances.

  • “Surgery is the only solution.”
    Many knee conditions can be treated non-surgically with exercise, physical therapy, and regenerative medicine.

Final Thoughts

Most knee cracking is harmless, but if it comes with pain, swelling, or instability, it is worth checking out. Strengthening muscles, stretching, and maintaining a healthy lifestyle can support knee health and reduce unwanted cracking.

Need expert advice? Book a consultation to keep your knees strong and pain-free.

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