Hyposmia

Hyposmia is a reduced ability to detect or identify odors, ranging from mild impairment to near-complete loss of smell. It can result from impaired odor access, damage to olfactory pathways, or altered neural processing.

Olfactory epithelium: A specialized tissue in the upper nasal cavity containing odor-detecting sensory neurons. Damage or inflammation here can prevent odors from activating sensory neurons.
Chronic rhinosinusitis: Persistent inflammation of the nasal and sinus lining, often with congestion or nasal polyps. Inflammation and polyps can block odor access or affect olfactory tissue.
Anosmia: The complete or nearly complete inability to detect odors. It marks the more severe end of smell loss compared with hyposmia.
Taste: The sensory experience produced when substances stimulate receptors in the mouth. Smell contributes strongly to flavor, so hyposmia can make food seem less flavorful.
Olfactory bulb: A forebrain structure that receives and processes signals from olfactory sensory neurons. Disruption of this first brain relay can weaken odor perception.
Nasal polyps: Noncancerous growths of inflamed tissue arising in the nasal passages or sinuses. Large polyps can obstruct airflow and diminish smell.
Parosmia: A distortion in which familiar odors smell different or unpleasant. Unlike reduced sensitivity, parosmia changes the perceived quality of odors.
Flavor: The combined sensory experience of taste, retronasal smell, and other oral sensations. Reduced retronasal smell can diminish flavor even when basic taste remains intact.
Olfactory nerve: The collection of sensory nerve fibers carrying odor signals from the nasal cavity to the brain. Injury to these fibers can reduce the signal reaching the brain.
Post-viral olfactory dysfunction: Impaired smell that persists after a viral infection affecting the respiratory tract. Viral illness can injure olfactory sensory neurons and leave lasting impairment.

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