A stuffy nose from a cold is a common cause for a partial, temporary loss of smell. A blockage in the nasal passages caused by a polyp or a nasal fracture also is a common cause. Normal aging can cause a loss of smell too, particularly after age 60.
Your nose and an area in the upper throat have special cells that contain odor receptors. When these receptors detect smells, they send a message to the brain. The brain then identifies the specific smell.
Any problem in this process — a stuffy nose, a blockage, inflammation, nerve damage or a brain function condition — can affect your ability to smell normally.
Conditions that cause temporary irritation or congestion inside your nose may include:
Conditions or obstructions that block the flow of air through your nose can include:
Nerves leading to the area of the brain that detects smell or the brain itself can be damaged or deteriorate due to:
Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.