What are smell and taste disorders?

The most common smell and taste disorders are:

• Anosmia. Loss of sense of smell.

• Ageusia. Loss of sense of taste.

• Hyposmia. Reduced ability to smell.

• Hypogeusia. Reduced ability to taste sweet, sour, bitter, salty things, or other flavors.

In other disorders, odors, tastes, or flavors may be misread or changed. They may cause you to get a bad odor or taste from something that is normally pleasant to smell or taste. These disorders can affect quality of life. They may also be a sign of an underlying disease.

Problems with taste and smell may be signs of certain health problems, such as:

• Obesity.

• Diabetes.

• COVID-19.

• High blood pressure.

• Poor nutrition.

• Nervous system diseases such as:

  • Parkinson disease.

  • Alzheimer disease.

  • Multiple sclerosis.

What causes smell and taste disorders?

Some people are born with these disorders, but most are caused by:

• Illness, such as cold or flu, COVID-19, sinus infection, and allergies.

• Head injury.

• Hormone changes.

• Dental or mouth problems.

• Nasal polyps.

• Exposure to certain chemicals.

• Certain medicines.

• Exposure to radiation therapy for head or neck cancer.

• Cocaine snorted through the nose.

• Cigarette smoking.

What are the symptoms of smell and taste disorders?

Symptoms can vary. Some people may not be able to smell or taste anything. Others may have a reduced ability to smell or taste certain things that are sweet, sour, bitter, or salty. In some cases, normally pleasant tastes or smells may become unpleasant.

How are smell and taste disorders diagnosed?

Along with a complete health history and physical exam, other tests may include:

• Measuring the lowest strength of a chemical that you can recognize.

• Comparing tastes and smells of different chemicals.

• "Scratch and sniff" tests.

• "Sip, spit, and rinse" tests where chemicals are placed on certain parts of the tongue.

How are smell and taste disorders treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment may include:

• Stopping or changing medicines that help lead to the disorder.

• Correcting the underlying health problem.

• Surgery to remove blockages that may be causing the disorder.

• Counseling.

• Quitting smoking.

• Smell retraining therapy (SRT). This is a process of repeatedly introducing different smells to stimulate the memory of that smell.

• Steroids taken by mouth or through the nose (as a nasal spray or flush). Steroids may help reduce swelling and inflammation that may be causing smell and taste problems.

• Platelet-rich plasma (PRP) therapy. This involves taking a sample of your blood. A lab identifies the components from your blood that help stimulate tissue healing. Your doctor then carefully injects these components into your nasal cavity to help repair your sense of smell and taste.

• Stellate ganglion block (SGB). SGB is a nerve block (shot) that is given in the nerves of the neck that help control the sense of taste and smell.

What are possible complications of smell and taste disorders?

Both smell and taste disorders affect quality of life. But smell disorders can be dangerous. They make you less able to notice such things as:

• Fire.

• Poisonous fumes.

• Leaking gas.

• Spoiled food and drinks.

Taste disorders can affect nutrition and lead to weight loss and malnutrition. They can also harm the immune system and make other health conditions worse.

Key points about smell and taste disorders

• Losing the senses of smell and taste are the most common smell and taste disorders.

• Other disorders include the reduced ability to smell or taste certain substances that are sweet, sour, bitter, or salty.

• For some people, normally pleasant tastes or smells may become unpleasant.

• Treatments for smell and taste disorders often include treating the underlying cause.

• Smell and taste disorders can affect quality of life and should be treated.

Next steps

Here are some tips to help you get the most from a visit to your doctor.

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your doctor tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new directions your doctor gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are and when they should be reported.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your doctor if you have questions.