With more severe hypokalemia, flaccid paralysis and hyporeflexia may result. There are reports of rhabdomyolysis occurring with profound hypokalemia with serum potassium levels less than 2 mEq/L. Respiratory depression from severe impairment of skeletal muscle function is found in many patients.

In the philosophy of language and modal logic, a term is said to be a non-rigid designator (or flaccid designator) if it does not extensionally designate (denote, refer to) the same object in all possible worlds.

In cases of motor neuron neurapraxia, symptoms consist of flaccid paralysis of the muscles innervated by the injured nerve or nerves.