A lost or changed sense of smell has become a recurrent complaint during the Covid-19 pandemic, as it’s a common symptom. The condition is often caused by an upper respiratory infection. Among the several types of olfactory disorders is parosmia, in which things smell abnormal and usually unpleasant. Smell training, also called olfactory training, can help restore a normal sense of smell, says the Lower Saxony Pharmacists’ Association in Germany (AKNDS). Having a persistently dysfunctional sense of smell can be very distressing – and downright dangerous if you can’t, for example, smell smoke o…