Neurons are vital for brain function and communication. Neurodegeneration, the irreversible loss of neurons, disrupts brain-body interactions, causing diseases like Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), multiple sclerosis (MS), and Parkinson's disease (PD). Factors like aging, genetics, and environment contribute to these disorders. They affect various neurons, leading to speech, movement, sensory, and balance issues. Alzheimer's features amyloid plaques affecting memory. Parkinson's stems from midbrain dopaminergic neuron loss, causing tremors and mobility problems. Huntington's, a basal ganglia disorder, results from a gene mutation, inducing involuntary movements. MS involves neuron demyelination, causing diverse complications. ALS entails motor neuron degeneration, resulting in muscle weakness and paralysis. This chapter aims to provide a brief overview of neurodegenerative diseases and an introduction to some of its key characteristics.