The true etiology of<unk>  has not been established, though several theories have been proposed. One popular theory is based on observations that many patients begin developing symptoms following a respiratory infection and dry cough, with one study finding 51 out of 65 patients contracted<unk>  after either a cough or respiratory infection. Thus, it has been hypothesized that the repetitive mild trauma of a severe cough from a respiratory infection may produce small tears in the ligament called microtrauma, causing<unk> . However, this theory is disputed as it does not account for symptoms such as the onset of attacks while at rest as well as the fact that swelling sometimes develops before a cough. The respiratory infection has also been observed accompanying rheumatoid arthritis which, coupled with leukocytosis, neutrophilia, c-reactive protein (CRP), and elevated erythrocyte sedimentation rate (ESR), suggest an infectious and rheumatoid factor, though the evidence is conflicting. Many theories such as malnutrition, chest trauma, and tuberculosis, were thought to be among the potential causes but have since been disproven or unsupported.
Tietze syndrome
Costochondritis
Galloway Mowat syndrome
Zechi-Ceide syndrome
Mungan syndrome
Schimmelpenning syndrome
Antley–Bixler syndrome
Havana syndrome