Disruptions in taste and smell have emerged as a Covid-19 symptom.  However, these sensory impairments can occur for several reasons other than Covid-19.  Sometimes these impairments are temporary and not serious, such as may occur with the common cold or flu.  At other times, the causes of loss of smell and taste can be long-term or even permanent.  It does not always mean that it is serious.  For example, the sense of taste and smell diminishes with age.  However, there are instances where the loss of taste and smell may be symptoms of severe and even life-threatening diseases.