The final paper deals with the impact of fatigue on people suffering from multiple sclerosis, a chronic autoimmune disease that affects the central nervous system. The paper explains in detail the myelin sheath, which plays an important role in the conduction of nerve impulses, and the disease itself. The processes of myelin formation and maintenance and potential causes of demyelination, including autoimmune disorders such as multiple sclerosis, are considered. Multiple sclerosis includes different forms of the disease, from the relapsing-remitting to the primarily progressive form, with different symptoms and disease courses. Diagnostics is based on a combination of clinical symptoms and paraclinical indicators, such as magnetic resonance imaging, lumbar puncture and evoked potentials. Each of the methods display essential information for identifying and monitoring the disease. Special attention is paid to the phenomenon of fatigue, which is one of the most common and severe symptoms of multiple sclerosis. Fatigue occurs in different forms, including central and peripheral fatigue, and can affect the quality of life of sufferers. The pathophysiology of fatigue encompasses primary and secondary mechanisms, and as such interventions in the treatment of fatigue require a multidisciplinary approach that includes pharmacological and non-pharmacological methods. The paper also emphasizes the importance of physiotherapy assessment and rehabilitation as important components in the care of patients with multiple sclerosis. Physiotherapy aims to improve motor functions, increase muscle strength and maintain range of motion.