Why Do Muscles Crack When Stretching?

Stretching your muscles at the end of a long day can feel relaxing and soothing but you might hear odd cracking or popping sounds.

Why Do Muscles Crack When Stretching?

If you wonder why do muscles crack when stretching and if you should be concerned about this strange noise, then read on.

Generally, a cracking sound coming from joints and muscles is absolutely safe. It’s a way for our body to release tension. But there is a great variety of other reasons why you may hear this sound.

In this article, we find out why your muscles crack, pop or creek and when you should see a doctor.

Reasons Why Muscles Crack

Scientists found a number of reasons why your muscles and joints may be producing a cracking sound. The scientific term for this phenomenon is “crepitus”.

While nothing in your body is breaking or snapping when you hear this noise, the muscle tissue might be moving. This is typically not harmful.

Pressure Release

Medical professionals believe that one of the most common reasons why muscles make a creaking sound when you are stretching is to release tension in specific areas.

Stretching moves hard and soft tissue in your body around which opens small spaces between tissue and muscle mass. These small gaps allow gas to enter. As you continue to move, this gas is expelled again and you can hear this as a form of popping sound.

Knots In Your Muscles

Knots deep inside your muscles could be another reason for this crunchy sound. When you rub these tension knots together, then you will hear a soft popping noise.

This shouldn’t be painful and muscle knots can often be resolved with some stretching and a comfortable massage. If you have a muscle knot that won’t go away, then it is best to contact a massage therapist who will be able to investigate this further.

Soft Tissue Movement

Another common reason for cracking sounds in your body during stretching exercises is tendons snapping in and out of place. You may have a tendon in your body that continually cracks when you move.

If it doesn’t hurt and you can feel the tendon moving, then there is no cause for concern. The repetitive motion of cracking tendons can happen, even with professional athletes.

Synovial Fluid

Synovial fluid lubricates our joints and any tissue around the joints. This makes it easier for the joints to move. If you make a sudden or quick movement, then you might hear popping sounds because the synovial fluid is pushed out of its place.



As we age, muscles and bones crack more. This is because the cartilage around our joints is wearing down slowly. This creates rougher surfaces around our joints and tissues which make a creaking sound.

Is It Normal For Muscles To Make Cracking Noises?

Yes, it is perfectly normal for your muscles, joints or tissues to make cracking, creaking or popping noises. As long as you don’t experience any discomfort or pain, then you don’t need to worry about these sounds.

When You Be Worried About Cracking Joints

While cracking and popping joints are commonly no cause for concern, there are some scenarios where you should check in with your doctor. Some symptoms, such as pain and swelling, can hint at problems with your joints, tendons or muscles.

Here are the signs you need to look out for when cracking your joints. If you notice any of these, then it is best to seek the advice of a doctor.

Pain And Swelling

If you experience swelling and pain around your joints while you are stretching and cracking, then this could be a sign of injury. You may have pinched nerves, torn ligaments or damaged cartilage that produces this sound.

These conditions can be serious and they will affect your mobility over time.

Pain and swelling near tendons can also be an indicator of bursitis or tendonitis. Tendonitis is a swollen tendon that moves a joint in an unusual way. This can lead to a cracking noise.

Bursitis is an inflammation of the tissue between your joints. If you notice pain in the cracking area even when you don’t move, then you may have bursitis.

Stiffness Or Loss Of Mobility

Pain and swelling in joints often leads to stiff muscles and eventually the loss of mobility. This could have a number of different reasons, including arthritis, an injury or other orthopedic conditions.

When the tissue around an affected area is swollen, then tendons cannot move smoothly anymore and they make a creaking sound. It is important that you speak to your doctor if you experience any form of muscle or joint stiffness to prevent the loss of mobility.

Cracking Lungs

While crepitus can occur all over the body, it should never happen inside your organs, especially not the lungs.

If you notice a cracking sound in your lungs when you breathe, then you should contact your doctor immediately. You may suffer from a lung infection, chest trauma or obstruction of the airways.

Areas That Make A Cracking Sound

As a rule of thumb, all your muscles, tendons, body tissue and joints can produce a cracking sound. The most affected areas are usually the wrist, knees, ankles, neck and back.

What Happens When You Make Your Joints Crack?

Cracking your joints intentionally is surprisingly common. It can give you a feeling of relief from tension and pressure in this area. In the past, doctors believed that intentionally cracking your joints would lead to arthritis. However, this has since been disproven.

While forcing your knuckles and other joints to crack isn’t specifically a bad thing, it can cause bigger problems. You may pinch a nerve or strain a muscle.

If you notice any discomfort or swelling after you cracked your muscles or joints, then it is best to contact an orthopedic specialist.

Final Thoughts

Although we often worry about the many sounds that come from our bodies, most cracking noises aren’t actually harmful. In fact, they can simply be a sign of your normal body movements.

Laura Simmons
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