Hyporeflexia is the reduction or absence of normal bodily reflexes.
The upper motor neurons are thought to inhibit the reflex arc, which is formed by sensory neurons from intrafusal fibers of muscles, lower motor neurons (including alpha and gamma motor fibers) and appurtenant interneurons.
Therefore, damage to lower motor neurons will subsequently result in hyporeflexia and/or areflexia.
[citation needed] In spinal shock, which is commonly seen in the transection of the spinal cord, hyporeflexia can transiently occur below the level of the lesion and can later become hyperreflexic.
[citation needed] Hyporeflexia may have other causes, including hypothyroidism, electrolyte imbalance (e.g., excess magnesium), and drug use (e.g, depressants).