Language disorders resulting from cerebral stroke or other focal brain lesions, as well as from some neurodegenerative diseases (aphasia) are common in neurological practice and have a negative impact on almost all kinds of social interaction and the quality of life of patients. The aim of this work was to study and summarize the information on aphasia in the world scientific lite-rature in order to achieve a consensus among representatives of different specialties and to optimize the diagnostic and treatment strategies in patients with language disorders. We searched for publications from 2001 to 2023 on language disorders in neurological diseases, diagnosis, and treatment of aphasia in the PubMed, Clinical Key Elsevier, Cochrane Library, and Google Scholar databases. The article highlights the historical aspects of the formation of modern ideas about language disorders and considers the main clinical forms of aphasia, their relationship with the topography of brain lesions. Diagnostic approaches in speech and language disorders include assessment of speech production, speech comprehension, naming, repetition, reading and writing, in addition to pronunciation and fluency, which is performed in clinical practice by neurologists, speech and language therapists. Based on a comprehensive assessment of language functions, language impairment can be classified as one or more of the seven main clinical forms of aphasia. The main predictors of a better recovery of language functions are a milder initial severity of aphasia, an earlier initiation of treatment and an adequate scope of therapy. The basis of treatment and rehabilitation for aphasia is speech and language therapy, which can be carried out by both specialists and the patient’s family or caregivers. The role of drug treatment and non-invasive brain stimulation in improving language functions is still very limited and requires further research. Teaching patients and their family certain rules of communication taking into account present language disorders is of great importance. Future treatment strategies for aphasia are likely to consist of a combination of a behavioral approach with pharmacotherapeutic and neuromodulatory interventions.