Although taste and smell are two distinct senses, they’re closely intertwined. The mouth and nose are connected, so sensations of taste and smell often reach the brain at the same time. It’s impossible to say just how much taste and smell affect each other, but anyone who has lost their sense of taste and smell knows that the two are closely related.

Loss of taste and smell has come into the spotlight because it can be a symptom of COVID-19. However, there are lots of other disorders that can cause loss of taste or smell. This article covers the conditions that can lead to loss of taste and smell, and what might help you regain those senses. 

Disorders Related to Loss of Taste and Smell

The loss of taste and smell or changes to those senses can present in a variety of ways. The olfactory disorders (disorders affecting smell) are: 

• Hyposmia: A reduced ability to smell
• Anosmia: Total loss of smell
• Parosmia: A change to the sense of smell. An example is something that used to smell bad to you but now smells good. 
• Phantosmia: Perceiving a smell that isn’t actually there

Taste disorders include:

• Ageusia: Complete loss of taste
• Hypogeusia: Decreased sense of taste
• Dysgeusia: Confusing different tastes
• Phantogeusia: Tasting something that is not present

These conditions can come up for a variety of reasons and might be temporary or permanent. If you experience loss of taste or smell, it’s important to get to the root cause of your olfactory or taste disorder. 

What’s Causing My Loss of Taste and Smell?

That root cause could be a number of things. In some cases, a change to taste or smell can be an early warning sign of another condition. Many people who report a problem with taste actually have an olfactory problem. Here are common causes for loss of taste and smell. 

• Age: The loss of taste, and in particular smell, can decrease or change as you age. It’s a normal part of the aging process. Generally, about 2% of people have issues with smell, but about 25% of men and 11% of women in their 60s have a smell disorder. Since the perception of smell and taste are connected, changes to your olfactory system might affect how you perceive taste. Taste buds also begin dying off after age 50.
• Hormone changes: Hormones can affect your sense of smell, particularly for cisgender females. Estrogen and progesterone are both linked to the olfactory system, so as hormones levels change—throughout a menstrual cycle, pregnancy, or menopause—they affect how you perceive scent.
• Nasal congestion or obstruction: The receptors for your factory system, or sense of smell, are located in the upper nose. If your nose is blocked, because of congestion caused by allergies or illness like the flu, a cold, or a sinus infection, it can stop smells from reaching those sensors. This is also why nasal polyps or other obstructions can impact your sense of smell. 
• COVID-19: COVID-19 affects taste and smell differently from other infections. The cold or flu might lessen your sense of smell because congestion blocks your nose. With COVID, the infection actually attacks the olfactory receptors. That’s why COVID causes loss of smell early on, even before congestion occurs, and why people with COVID can experience loss of smell without congestion. 
• Concussion or head injury: Up to half of people who have mild concussions will temporarily lose their sense of smell. Head trauma can affect the nasal passages and the olfactory nerve, which carries the sensation of scent to the brain. It can also impact the areas of the brain where olfactory signals are processed. Most people regain their sense of smell within six months of the injury.
• Conditions of the brain or nervous system: In order to smell something, a signal must be sent from receptors in your nose, to the olfactory nerve, to the brain. Conditions that affect the brain and nervous systems can interrupt this process and lead to a loss of smell. These include Parkinson's disease, Alzheimer's disease, and diabetes.
• Chemicals, smoking, and drugs: Exposure to certain chemicals, including those found in cigarettes, can diminish one’s sense of smell. Smoking, recreational drug use, and insecticides can all leave you with a diminished sense of smell and taste.

Diagnosis of Loss of Taste and Smell

If you have lost your sense of taste and smell, you should visit an otolaryngologist, or ENT. This is a doctor who specializes in the ears, nose, and throat. 

An ENT will use tests to determine how severe your loss of smell or taste is, and whether particular odors or tastes are impacted more than others. Some tests measure the smallest amount of smell or taste that you can detect. Others ask you to correctly identify certain tastes or smells.

The Importance of Diagnosis

Losing smell or taste might sound minor—until you experience it. Smell and taste are both important for overall health. A strong sense of smell can help you identify dangers like a gas leak or spoiled food. A sense of taste is important for feeling satisfied while eating. People with loss of taste and smell are at increased risk for diabetes, high blood pressure, and depression.

Treating Loss of Taste and Smell

If you lose your sense of taste or smell, you should talk to a healthcare professional. They will work to identify the cause of your loss. That will determine what treatment is used. 

If your loss is due to a medical issue, addressing that can help return your sense of smell. This might mean changing medications, getting treatment for congestion, or starting an allergy medication. 

In other cases, like with COVID-19 or a concussion, you’ll have to wait for your senses of taste and smell to return. Some people experience a spontaneous return or their sense of taste and smell but, in rare cases, the conditions can be permanent. 

You can also adopt lifestyle changes to enhance sensations of taste and smell. Cooking with aromatic ingredients, using bold colors, or adding spices can increase your satisfaction from meals. Counseling can also help with the emotional side of losing your sense of taste and smell.

Summary

Loss of taste and smell can happen for many reasons. It might be due to a virus, including COVID-19. But it can also be a warning sign for serious medical issues, including dementia or a concussion. If you experience a loss of taste or smell, it’s important to talk with your healthcare professional. They can help you treat what is causing it and determine if you need further care.

A Word From Verywell

Coping with the loss of taste and smell, even temporarily, can be difficult. It’s important to maintain a healthy diet even when your sensations are limited. Talk to your healthcare provider about tips for enhancing satisfaction from meals. At the same time, be sure to address the emotional impacts of losing your sense of taste and smell.