Anosmia is the loss of the sense of smell. Anosmia may be temporary or permanent and can be caused by brain and or head injuries, illness and chemical exposure. Anosmia can even be deadly. For example, a person with Anosmia cannot smell smoke in a burning building or identify that the food they are eating is spoiled.

An estimated five million American adults suffer from disorders of taste and smell. More than 200 medical conditions and many prescription medications have been associated with olfactory changes and loss.

Zicam, a popular Zinc nasal cold gel, has been linked to a condition known as Anosmia. Zicam is an intranasal zinc solution. Intranasal zinc has been known to kill the ability to smell by both animals and people for many years. For years there had been no use of intranasal zinc in humans. However because Zinc products fall under the homeopathic provision of FDA laws, these products are not required to get FDA approval before they hit the market.

Therefore its not startling that studies revealed that Zinc nasal cold sprays and gels, like Zicam, not only have dangerous side effects but are ineffective against colds. While two placebo-controlled trials found that intranasal zinc gluconate modestly shortened the duration of cold symptoms two other placebo-controlled studies found intranasal zinc to be of no benefit at all.

In addition to Anosmia, there are other variations of loss of smell. Hyposmia is individuals reduced ability to smell and to detect odors.

Hyperosmia is an abnormally increased sensitivity to odors or an abnormally increased sense of smell. Parosmia involves a distortion of the sense of smell, the affected person reports smelling something other than the scent that is present.

Phantosmia involves olfactory hallucinations, there are no odorants present, but the affected person reports smelling something, generally unpleasant. Dysosmia is an impairment of the sense of smell.