GBS. Guillain-barre syndrome presents with progressive weakness starting at distal parts of limbs and moving upwards towards the torso. The extremity eventually may become limp. It can also affect the respiratory muscles and the patient my end up on a ventilator in an icu. Other unusual symptoms are changes in heart and blood pressure.
Muscle weakness. This is a allergic/toxic reaction to the nervous system in response to an immunologic insult - most commonly a viral infection. The areas affected, usually starting with the legs and passing upwards can make you helpless and even stop breathing. This is an emergency and you should seeks help immediately.