Anosmia

Anosmia is the loss of sense of smell, hyposmia is a reduced sense of smell, parosmia is an altered sense of smell, and phantosmia is when you smell things that aren't there. A change in sense of smell may occur alongside a change in sense of taste.

Prevalence in ME/CFS

 * 2001, In a very largeBelgian study, 38.0% of patients meeting the Fukuda criteria for chronic fatigue syndrome and 42.4% of patients meeting the Holmes criteria, in a cohort of 2073 CFS patients, reported changes in taste, hearing or smell.

Causes
Common causes include
 * obesity
 * diabetes,
 * hypertension (high blood pressure)
 * poor nutrition
 * nervous system diseases, e.g., Parkinson's disease, Alzheimer's disease, or multiple sclerosis
 * colds, flu or flu-like illnesses, sinus problems and allergies
 * an altered or loss of smell and taste may also be caused by COVID-19 illness or long COVID

Learn more

 * Smell and taste disorders - Johns Hopkins University