Weakness is a challenging and broad chief complaint in emergency medicine, necessitating rapid and accurate differentiation among numerous etiologies. Effective diagnosis involves recognizing symptoms of central and peripheral neurologic disorders, neuromuscular junction diseases, nutritional deficiencies, and toxin exposures. Prompt identification and intervention in conditions such as Guillain-Barré syndrome, transverse myelitis, botulism, and nutritional deficiencies are crucial. Despite vaccines reducing cases of polio, tetanus, and diphtheria, vigilance remains essential due to their potential resurgence. This article emphasizes a systematic evaluation, critical diagnostic challenges, management pitfalls, and future directions for improving patient outcomes.