Age-related taste loss: As people age, the number of taste buds on the tongue decreases, leading to a decline in taste sensation. This is a common and expected change that occurs with aging.

Upper respiratory infections: Conditions like the common cold, flu, or sinus infections can cause temporary inflammation and congestion in the nasal passages, leading to a decrease in taste.
Medication side effects: Certain medications, such as antibiotics, antihistamines, and decongestants, can alter taste perception as a side effect.
Nutritional deficiencies: Deficiencies in vitamins like zinc, vitamin B12, or iron can affect taste sensation.
Dental problems: Gum disease, tooth decay, or dental appliances can cause changes in taste.

Neurological disorders: Conditions like multiple sclerosis, Parkinson's disease, or stroke can damage the nerves responsible for taste, leading to a decrease in taste sensation.
Head and neck cancer: Tumors in the head and neck region can affect the taste buds or the nerves that transmit taste information to the brain.
Infections like meningitis or encephalitis: These serious infections can cause inflammation in the brain and affect taste perception.

Sjögren's syndrome: An autoimmune disorder that can cause dry mouth and decreased taste.
Bell's palsy: A condition that causes temporary paralysis of the facial nerve, which can affect taste.
Chemosensory disorders: Rare conditions like hyperosmia (an increased sense of smell) or hypogeusia (a decreased sense of taste) that can be caused by genetic or environmental factors.
Gustatory sweating (Frey's syndrome): A rare condition that causes abnormal sweating and flushing of the face in response to certain tastes or smells.