Most of those diagnosed with AFM report having a respiratory or gastrointestinal illness before the onset of weakness. The predominant presentation is a rapid onset of weakness that may affect the limbs, face, oropharyngeal muscles, or the muscles that control breathing. Those with AFM may not be able to breathe, swallow, or move their eyes normally. Weakness varies greatly ranging from mild to very severe. AFM may result in weakness, partial paralysis, or total paralysis of just one limb or all limbs. The pattern of paralysis and how individuals present are widely variable. Weakness most often occurs in proximal muscles, meaning the muscles closest to the center of the body. Pain in the neck, back, or limb may be an early symptom. Autonomic instability, such as issues with heart rate, may occur as well. Since it is mainly the gray matter of the spinal cord that is damaged in individuals with AFM, they may not have bladder or bowel dysfunction or issues with sensation. However, some individuals may have inflammation in both the white and gray matter of the spinal cord (upper and lower motor neuron), so some of those with AFM may experience impaired sensation, bladder, and/or bowel dysfunction.