Crepitus (; also termed crepitation) is a medical term to describe the grating, crackling or popping sounds and sensations experienced under the skin and joints or a crackling sensation due to the presence of air in the subcutaneous tissue. Various types of crepitus that can be heard in joint pathologies are: Bone crepitus: This can be heard when two fragments of a fracture are moved against each other. Joint crepitus: This can be obtained when the affected joint is passively moved with one hand, while the other hand is placed on the joint to feel the crepitus. Crepitus of bursitis: This is heard when the fluid in the bursa contains small, loose fibrinous particles. Crepitus of tenosynovitis
Crackles, crepitations, or rales ( ( listen) RAHLZ or RALZ) are the clicking, rattling, or crackling noises that may be made by one or both lungs of a human with a respiratory disease during inhalation. They are often heard only with a stethoscope ("on auscultation"). Bilateral crackles refers to the presence of crackles in both lungs. Basal or basilar crackles (not to be confused with the basilar artery of the brain) are crackles apparently originating in or near the base of the lung. Bibasal or bibasilar crackles refer to crackles at the bases of both the left and right lungs. Bilateral basal crackles also refers to the presence of basal crackles in both lungs. Crackles are caused by the "popping open" of small airways and alveoli collapsed by fluid, exudate, or lack of aeration during expiration. The word "rales" derives from the French word râle meaning "rattle". Crackles can be heard in patients with pneumonia, atelectasis, pulmonary fibrosis, acute bronchitis, bronchiectasis, interstitial lung disease or post thoracotomy or metastasis ablation. Pulmonary edema secondary to left-sided congestive heart failure can also cause rales.
Borrowed from Latin crepitus.