The exact etiology is unknown, although research supports the likelihood of a genetics basis; neuroimaging techniques have not identified a clear common pathology.

Several theories exist on its exact etiology.

The exact etiology is unknown, but the cloudiness may be caused by excessive exposure to light or by trauma.

The exact etiology of tendinopathies has not been fully elucidated and different stresses may induce varying responses.

Although the exact etiology or cause of stuttering is unknown, both genetics and neurophysiology are thought to contribute.

The exact etiology remains unknown, but abnormalities in the lateral body wall folds are believed to be involved.

The exact etiology of the disease remains uncertain, but extensive research suggests an interaction between genetic predisposition and environment.

The exact etiology of senescence is still largely unclear and yet to be discovered.

The exact etiology of it is not known.

Although the exact etiology is unknown, there is evidence that it is caused by an immune mediated response.