The diagnosis of aphasia typically begins with a clinical evaluation where the physician assesses the patient's symptoms to determine the potential type of aphasia. Beyond this initial assessment, various diagnostic tests, particularly imaging studies, are employed to confirm the diagnosis and identify underlying causes.

Common diagnostic tests used in aphasia diagnosis include:

Computed Tomography (CT) scan
Magnetic Resonance Imaging (MRI)
Electroencephalogram (EEG)
Genetic test
Electromyography
X-rays