Crepitus and the Crackling Sounds in Your Joints

Crepitus is the abnormal popping or crackling sound in either a joint or the lungs, which may be faint or loud enough for people to hear. It is often accompanied by a popping or crunching sensation that may sometimes be uncomfortable or painful.

Crepitus in the joints is typically related to joint damage. Crepitus in the lungs is caused when collapsed or fluid-filled air sacs abruptly open upon inspiration.

Crepitus of the Joints

Crepitus may occur in tandem with a joint disorder or entirely on its own. As a symptom, it is not inherently problematic. Cracking your knuckles, for example, is a form of crepitus wherein tiny nitrogen bubbles in a joint suddenly pop with strenuous movement.

It is generally only a problem when the popping is progressive or is accompanied by symptoms of joint damage, injury, or infection.

Joint Damage

Crepitus can occur when the roughened surfaces of two joints rub together, causing the physical grating of cartilage and/or bone.

If the pain is felt, it is typically related to advanced joint damage and/or the compression of nerves between narrowed joint spaces. It is at this stage that the joint may begin show signs of injury, including swelling, redness, reduced range of movement, and malformation.

Osteoarthritis ("wear-and-tear arthritis") is the most common cause of this, although crepitus can occur with other forms of arthritis, including rheumatoid arthritis, psoriatic arthritis, gout, and juvenile idiopathic arthritis. It can affect any joint of the body but is most common in the knees, hands, feet, lower back, hips, and shoulders.

Joint Inflammation or Injury

Crepitus can also occur in special forms of arthritis or when structures around the joint are inflamed or injured. These types of disorders are usually accompanied by pain and the marked restriction of movement.

• Bursitis: This is inflammation of the fluid-filled sacs near the joint called bursa. It may be caused by an infection, autoimmune disorder, trauma, or a repetitive use injury. Crepitus can occur when the inner surfaces of an inflamed bursa rub against each other.
• Tenosynovitis: With this, inflammation builds up in the lining of the tendon sheath called the tenoysnovium, which surrounds a joint tendon. Crepitus can occur when a tendon slides through an inflamed sheath.
• Patellofemoral pain syndrome (PFPS): Also known as runner's knee, this is caused when the cartilage under the kneecap (patella) is damaged. This roughened cartilage can cause crepitus during knee movement.
• Temporomandibular joint disorders (TMJ), which are characterized by pain and other symptoms related to problems in the TMJ, the articulations between the jaw and the base of the skull. People with TMJ arthritis can sometimes hear crepitus with jaw movement. TMJ disorders can also result in both a clicking sound and popping sensation as you open your mouth.

Almost any injury of the joint cartilage can cause clicking or popping sounds as the uneven surfaces rub together. Rotator cuff tears and triangular fibrocartilage complex (TFCC) of the wrist are two such examples. Even abnormally-shaped cartilage, such as with discoid lateral meniscus (misshapen disc in the knee), can trigger this effect.

A less common cause of crepitus is scleroderma, a rare disorder characterized by the hardening and tightening of the skin and connective tissues. When this happens, it can cause coarse creaking sounds and sensations as the muscles and tendons rub against inflamed or hardened tissues.

Crepitus of the Lungs

While we typically apply the term "crepitus" to the joints, it can also be used to describe audible crackling sounds in the lungs. Also referred to as crackles or rales, the sounds are related to abnormalities in the lungs, typically accumulation of excess fluid or lung scarring.

Among some of the conditions for which rales are common:

• Pulmonary edema, typically associated with congestive heart failure (CHF)
• Pneumonia
• Bronchitis, either caused by infection or associated with chronic obstructive pulmonary disease (COPD)
• Interstitial lung diseases affecting the interstitium (the tissue surrounding the alveoli)

Diagnosis and Treatment

If crepitus is detected, the diagnostic process can vary depending on the location the sounds are coming from, the severity, and accompanying symptoms.

Joint Disorders

In some cases, the popping of a joint may be more irritating than problematic and, as such, may not warrant investigation or treatment. If there is pain, inflammation, or restriction of motion, your doctor may order tests to pinpoint the cause. These may include:

• Imaging tests such as ultrasound, X-ray, or computed tomography (CT) to detect bone or joint injury, or magnetic resonance imaging (MRI) to detect soft tissue damage
• Blood tests to check for infection or inflammation
• Antibodies tests to confirm autoimmune disorders such as rheumatoid arthritis
• Arthrocentesis in which fluid is extracted from the joint space with a needle for analysis in the lab

Treatment may involve ice application and non-steroidal anti-inflammatory drugs (NSAIDs) to alleviate mild to moderate inflammation and pain. Severe cases may require splinting or intraarticular steroid injections to help further reduce inflammation.

Infectious causes of joint inflammation are most often bacterial and may require a short course of antibiotics. Immune suppressive drugs are sometimes used to treat inflammatory autoimmune diseases.

Severe injuries (such as torn tendons, ligaments, or cartilage) may require surgery, typically performed arthroscopically with keyhole incisions. If your mobility or quality of life is significantly impaired, joint replacement surgery may be considered, accompanied by extensive rehabilitation and physical therapy.

When you return to routine exercise, modifications such as opting for low-impact activities and using lighter weights can help keep crepitus in check.

Lung Disorders

Crepitus of the lungs is never considered normal. Depending on your medical history and accompanying symptoms, the following tests may be ordered:

• Chest X-ray or CT scan to view your lungs
• Blood or sputum tests to identify the source of an infection
• Pulse oximetry to measure your blood oxygen level
• Electrocardiogram (ECG) or echocardiogram (EKG) to check for heart irregularities

The treatment can vary based on whether the condition is acute or chronic.

Doctors will typically treat bacterial pneumonia or bronchitis with antibiotics. Viral infections may be treated with antiviral drugs but are more often allowed to run their course with bed rest and plenty of fluids.

Chronic conditions usually require lifestyle changes, including smoking cessation, exercise, and the avoidance of airborne irritants. Conditions like COPD will generally require oral or inhaled corticosteroids and bronchodilators. Pulmonary rehabilitation and oxygen therapy can help prevent disease progression and maintain a quality of life.

Pulmonary edema may require the aggressive treatment of the underlying heart failure, ranging from chronic medications to bypass surgery. Surgery may be an option for people with advanced lung disease when all other treatments fail. A lung transplant is a last resort for those who lungs are no longer functional.

A Word From Verywell

Crepitus may be a sign of a serious illness or mean nothing at all. If uncertain about whether a clicking or crackling sound is problematic, always err on the side of caution and get checked out. If there is pain, swelling, redness, or you are suddenly less able to move a joint, do not hesitate to schedule an appointment with a doctor or orthopedist.

However, if you ever hear crackling sounds when you breathe, see your doctor as a matter of urgency whether or not there are any other symptoms. The earlier you do so, the more likely you will be to identify and treat the condition before it turns serious.