Crepitus (pronounced "krep-it-us") is the medical term used to describe a grinding, crackling or grating sensation and/or sound in the body. It is most commonly used to describe joint cracking, such as knee joint cracking or grinding. It may also be used to describe similar symptoms with other body functions, such lung crackling from pneumonia or other respiratory illnesses, or as a symptom of a fractured bone.
The term stems from the Latin word crepāre, which means to crack. Crepitus is also called crepitation (pronounced krep-i-tay-shen).
Often, the sound associated with crepitus may be quiet or muffled. However, the crunching or cracking sensation can be felt if one places a hand over the knee cap and gently moves the lower leg forward and backward.
Crepitus is a prominent symptom of arthritis – either osteoarthritis or rheumatoid arthritis. It is particularly common in arthritis of the knee joint. This symptom occurs because as arthritis causes the cartilage in the affected joint to degenerate, the cushioning function of the cartilage is lost and the bones tend to grind against one another.
- Read more about Knee Osteoarthritis
Crepitus is commonly described as any of the following sensations and sounds that occur when moving the affected joint:
- Creaking or cracking
- Popping (less common)
Crepitus can occur with or without pain. If it occurs without any pain it is unlikely to be caused by arthritis or any medical condition, and is usually meaningless. In fact, most people’s joint crack or pop occasionally, and this in considered normal. Joint cracking is only possibly an indication of a medical condition if it is regular and is accompanied by pain and possibly swelling or other concerning symptoms.
Most frequently, crepitus is associated with any of the above sensations as the knee bends back and forth. It may also be used to describe the above symptoms in other joints, especially those affected by arthritis, such as the hip, shoulder, neck and spine.
Recommended treatment for crepitus will depend on its cause. For crepitus caused by arthritis, the arthritis treatment will focus mainly on treating any pain and disability caused by arthritis, as crepitus in and of itself will not need treatment.