Bitter Taste In Mouth

A sour taste in your mouth after eating is a symptom of GERD, a chronic condition that affects the lower esophageal sphincter (LES). GERD can also cause heartburn, chest pain, and a burning feeling in your throat.

Why Do I Have a Sour Taste in My Mouth?

You may have a sour taste in your mouth after eating if you “burp up” something you recently ate. But a sour or acid-like taste in the mouth can happen for a variety of other reasons at different times, too. Some, like smoking and poor dental hygiene, are avoidable. Others, like hormone changes and aging, are not.

A sour taste in the mouth can also be due to several different health conditions ranging from dry mouth, nutritional deficiency, and gastroesophageal reflux disease (GERD) to infections like COVID-19, nerve disorders, and anxiety. Some medications and other treatments may also cause a sour taste.

Verywell / Laura Porter

This article discusses these and other possible causes of a sour taste in your mouth. It also discusses how to find out what’s causing it and how it can be treated.

Any change in your taste perception is called dysgeusia . It is one of several conditions that affect your sense of taste. Other disorders include the loss of taste sensitivity ( hypogeusia) and the complete loss of taste ( ageusia ).

Oral Health Issues

A health condition affecting the mouth is probably an obvious potential cause of taste changes. When it comes to developing a sour taste in the mouth, there are a few possibilities:

Dry mouth syndrome ( xerostomia ): This happens when you don’t have enough saliva. Since this fluid is required for digestion, an insufficient amount can change how food tastes and leave a bad taste in your mouth. Some health conditions cause dry mouth, as can certain medications and treatments.
Oral candidiasis: A yeast infection in the mouth/throat is also called thrush. People with weak immune systems are more likely to get oral thrush, which can also cause white patches on the tongue and mouth.
Burning mouth syndrome: This uncommon condition can cause a burning or scalding sensation in the mouth and taste changes that don’t have a clear cause. Sometimes, it appears to be linked to certain health conditions or medications. Burning mouth syndrome can be hard to diagnose and treat. It seems to be more common in people after menopause.

Habits

Certain habits can also contribute to a sour taste in your mouth. Luckily, if one of these is the only cause, you can make changes that can eliminate this symptom (or, in the case of smoking, at least prevent it from getting worse):

Cigarette smoking: Smoking can change how food tastes and dull your sense of taste. Cigarettes, vapes, and smokeless tobacco products can also leave a bad taste in your mouth.
Poor dental hygiene: If you don’t brush and floss your teeth and tongue regularly, the buildup of food particles can leave a sour taste in your mouth—even if you don’t have an oral health condition.
Dehydration: Not drinking enough fluid throughout the day can let your mouth get too dry, which can cause a sour taste.

Hormone-Related Causes

Fluctuations in female hormones can cause changes in your sense of taste. These are likely to occur at the following times:

Menstruation: Some people notice that their sense of taste changes at different points in their menstrual cycle. In addition to having a strange taste in your mouth during your period, you could also prefer different flavors at certain times in your cycle (e.g., you crave something salty when you’re pre-menstrual).
Pregnancy: Hormonal shifts that are a normal part of pregnancy can change taste perception, especially during the first trimester.
Menopause: Similar to how pregnancy can alter your sense of taste and taste preferences, the hormonal shifts around the time of menopause can also change it.

Aging

Your senses, including your sense of taste, change as you get older. This is independent of the hormonal changes discussed above and can happen in both men and women.

You may find that food doesn’t taste the way it used to, or you have a bad taste in your mouth at other times.

Zinc Deficiency

Not having enough zinc in your body is one of the more common causes of a sour taste in your mouth after eating. People often say it’s “strange,” “off,” or simply “bad.”

Possible reasons you may not have enough zinc in your body include:

A diet lacking in zinc-rich foods like meat, fish, and seafood
Certain medical conditions (e.g., ulcerative colitis, liver disease)
Use of certain medications (e.g., ACE inhibitors, diuretics)
Having certain medical treatments (e.g., chemotherapy)

Other Health Conditions

Conditions unrelated to oral health can also cause a sour taste in the mouth for different reasons

Gastrointestinal Reflux Disease (GERD)

A sour taste in your mouth after eating is a symptom of GERD, a chronic condition that affects the lower esophageal sphincter (LES). GERD can also cause heartburn, chest pain, and a burning feeling in your throat.

Acid reflux triggers like smoking, alcohol, fatty or acidic foods, and eating a big meal can worsen symptoms.

Infection or Illness

Fighting an infection or illness in any part of your body can affect your senses.

For example, you probably know what it’s like to have a stuffy nose from a cold and not be able to smell or have food taste odd. A sinus infection or phlegm from a bad cough can also give you an off taste in your mouth.

Can COVID Cause a Sour Mouth?

COVID-19 is known to change your sense of taste, which can include causing a sour taste in your mouth. While some people notice that this improves once the infection clears, taste changes can linger for months. Paxlovid, a COVID treatment, can also cause a bad taste in the mouth—so much so the symptom has been dubbed “Paxlovid mouth.”

Pine Nut Syndrome

This condition causes a bitter taste one to three days after eating pine nuts. Sometimes, it can linger for weeks.

Anxiety and Stress

Mental health conditions like anxiety can change your sense of taste. Periods of extreme stress may also have this effect. Stress and anxiety can also make your mouth dry, which may change the way you perceive flavors.

Brain and Nerve-Related Concerns

Your brain is integral to the taste experience. Some people with brain injuries get phantom taste or smell sensations. This may also occur after brain surgery.

Brain and nerve conditions can also change your sense of taste. Some of the conditions that may have this effect include:

Lead Poisoning

If you’ve been exposed to lead, you may notice a blue line along your gums and have a strange or bad taste in your mouth.

Lead poisoning also causes symptoms like fatigue, trouble concentrating, and memory loss.

Medications and Treatments

A bitter or sour taste in your mouth after eating can be a side effect your medication. More than 200 different drugs can cause a bitter taste in the mouth.

This side effect could be caused by:

How the drugs affect taste receptors in the brain
The taste of the medication when it’s mixed with saliva
A drug molecule in a blood vessel of the tongue interacting with taste bud receptors

Sour Taste During Cancer Treatment

People being treated for cancer in the head and neck can have taste changes because radiation damages salivary tissues. Chemo can also change your sense of taste.

Figuring Out the Cause of a Sour Taste in the Mouth

Treating a sour taste in your mouth depends on what’s causing it. If there is no obvious cause or the symptom persists, see your healthcare provider.

They will ask you about your symptoms, lifestyle, any medications you take, and any health conditions you have. They may want to look inside your mouth and run some tests, depending on what causes they suspect.

If they think you have GERD, special tests can check your esophagus (e.g., endoscopy or manometry).
Blood tests can check your zinc levels and look for signs of an infection or inflammation.

Getting Rid of a Sour Taste

You may need a specific treatment(s) to address this. For example:

If you are not getting enough zinc in your diet, you may need to eat more foods that contain it, like legumes, eggs, and red meat. You may also need to take a zinc supplement.
If you have GERD, changes to your diet and lifestyle (like losing weight and avoiding trigger foods) may help. Acid relievers, H2 blockers, or proton pump inhibitors may also be recommended.
If you have dry mouth, special rinses and lozenges can help moisten your mouth and cover up the bad taste.
If you have yeast overgrowth in your mouth, your dentist or provider might give you an antibacterial rinse to use.
If you are getting a bad taste in your mouth as a side effect of a medication, your provider might suggest trying a different drug or taking your medication differently.

Prevention

Regardless of the cause of the sour taste, these general strategies can help you better cope with this symptom and reduce the likelihood of it continuing:

Make oral hygiene a priority: Brush twice daily, floss at least once daily, use antibacterial mouthwash, and get regular dental checkups.
Drink plenty of water: Not only does hydrating keep your mouth moist, but it also makes you urinate more. This can help flush out any substances in your body that might be contributing to your symptoms.
Chew sugar-free gum: Gum chewing encourages your mouth to make saliva, which can prevent it from getting too dry. The flavor of the gum can also cover up a bad taste.
Rinse your mouth: Make a rinse using a half-teaspoon of salt and a teaspoon of baking soda added to a glass of water. Swishing with this solution can help clear out a bad taste.
Avoid spicy or fatty foods: Try to limit or avoid any foods or beverages that trigger acid reflux.
Stop smoking: Whatever the underlying cause of the bad taste in your mouth, cigarette smoking or tobacco use will worsen the problem.

Summary

If you have a sour taste in your mouth after eating, the simplest explanation is that it was just something you recently ate. A bad taste in your mouth can also be caused by medications, nutritional deficiency, GERD, and other health conditions.

The treatment for a bad taste in your mouth depends on the cause, but you can cope with the symptom by drinking lots of water, taking care of your oral hygiene, and quitting smoking.

22 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Johns Hopkins. Smell and taste disorders.
Villa A, Connell CL, Abati S. Diagnosis and management of xerostomia and hyposalivation. Ther Clin Risk Manag. 2015;11:45-51. doi.org/10.2147/TCRM.S76282
Sharma A. Oral candidiasis: An opportunistic infection: A review. Int J Appl Dent Sci. 2019;5(1):23-7.
National Institute of Dental and Craniofacial Research. Burning mouth syndrome.
Chéruel F, Jarlier M, Sancho-Garnier H. Effect of cigarette smoke on gustatory sensitivity, evaluation of the deficit and of the recovery time-course after smoking cessation. Tob Induc Dis. 2017;15:15. doi:10.1186/s12971-017-0120-4
Stanić Ž, Pribisalić A, Bošković M, et al. Does each menstrual cycle elicit a distinct effect on olfactory and gustatory perception?Nutrients. 2021;13(8):2509. doi:10.3390/nu13082509
Choo E, Dando R. The impact of pregnancy on taste function. Chem Senses. 2017;42(4):279-286. doi:10.1093/chemse/bjx005
Skoczek-Rubińska A, Chmurzynska A, Muzsik-Kazimierska A, Bajerska J. The association between fat taste sensitivity, eating habits, and metabolic health in menopausal women. Nutrients. 2021;13(12):4506. doi:10.3390/nu13124506
National Institues on Aging. How smell and taste change as you age.
Hata H, Ota Y, Uesaka K, et al. Oral adverse events due to zinc deficiency after pancreaticoduodenectomy requiring continuous intravenous zinc supplementation: a case report and literature review. BMC Oral Health. 2022;22(1):52. doi:10.1186/s12903-022-02088-3
Kabadi A, Saadi M, Schey R, Parkman HP. Taste and smell disturbances in patients with gastroparesis and gastroesophageal reflux disease. J Neurogastroenterol Motil. 2017;23(3):370-377. doi:10.5056/jnm16132
Harvard Medical School. Sinusitis.
Asad M, Sehanobish E, Fong V, et al. Loss of sense of smells associated with sour taste is a possible diagnostic marker for COVID-19. J Allergy Clin Immunol. 2021;147(2):AB163. doi:10.1016/j.jaci.2020.12.581
Santos REA, da Silva MG, do Monte Silva MCB, et al. Onset and duration of symptoms of loss of smell/taste in patients with COVID-19: A systematic review. Am J Otolaryngol. 2021;42(2):102889. doi:10.1016/j.amjoto.2020.102889
Food and Drug Administration. Frequently asked questions on the emergency ese authorization for Paxlovid for treatment of COVID-19.
Risso DS, Howard L, Vanwaes C, Drayna D. A potential trigger for pine mouth: a case of a homozygous phenylthiocarbamide taster. Nutr Res. 2015;35(12):1122-5. doi:10.1016/j.nutres.2015.09.011
Sawai A, Motomura T, Oshima T, et al. Influence of acute mental arithmetic stress on taste and pungency. J Nutr Sci Vitaminol (Tokyo). 2019;65(3):224-232. doi:10.3177/jnsv.65.224
Mehkri Y, Hanna C, Sriram S, et al. Overview of neurotrauma and sensory loss.J Neurol Res Rev Rep. 2022;4(3):10.47363/JNRRR/2022(4)158. doi:10.47363/JNRRR/2022(4)158
UT Health Houston. Dysgeusia.
Ramírez Ortega D, González Esquivel DF, Blanco Ayala T, et al. Cognitive impairment induced by lead exposure during lifespan: Mechanisms of lead neurotoxicity. Toxics. 2021;9(2):23. doi:10.3390/toxics9020023
Wang T, Glendinning J, Grushka M, Hummel T, Mansfield K. From the Cover: Drug-induced taste disorders in clinical practice and preclinical safety evaluation. Toxicol Sci. 2017;156(2):315-324. doi:10.1093/toxsci/kfw263
Murtaza B, Hichami A, Khan AS, Ghiringhelli F, Khan NA. Alteration in taste perception in cancer: Causes and strategies of treatment. Front Physiol. 2017;8. doi:10.3389/fphys.2017.00134

Additional Reading

Syed Q, Hendler K, Koncilja, K. The Impact of Aging and Medical Status on Dysgeusia. Amer J Med. 2016;129(7):e1-e753. doi:10.1016/j.amjmed.2016.02.003.

We Care About Your Privacy

We and our 100 partners store and/or access information on a device, such as unique IDs in cookies to process personal data. You may accept or manage your choices by clicking below, including your right to object where legitimate interest is used, or at any time in the privacy policy page. These choices will be signaled to our partners and will not affect browsing data.

We and our partners process data to provide:

Store and/or access information on a device. Use limited data to select advertising. Create profiles for personalised advertising. Use profiles to select personalised advertising. Create profiles to personalise content. Use profiles to select personalised content. Measure advertising performance. Measure content performance. Understand audiences through statistics or combinations of data from different sources. Develop and improve services. Use limited data to select content. List of Partners (vendors)

Dysgeusia

Dysgeusia is a taste disorder. People with this condition feel that all foods taste metallic, sweet, sour or bitter. Many things can cause dysgeusia, like smoking, medical conditions, medication or poor oral hygiene. Treatment addresses the underlying cause, like quitting smoking, changing medication or improving oral hygiene.

Overview

What is dysgeusia?

Dysgeusia (pronounced “dis-gyoo-zee-uh”) is a disorder that distorts your sense of taste. People with this condition often say that anything they eat tastes like metal, rancid or bitter. Dysgeusia isn’t a serious medical condition. But it can affect your appetite and quality of life. Healthcare providers may use the terms “altered taste” or “parageusia.”

Dysgeusia is different from ageusia, which is when you lose your sense of taste.

Is dysgeusia common?

Research suggests up to 17% of people in the U.S. experience dysgeusia at some point in their lives.

Symptoms and Causes

What are the symptoms of dysgeusia?

Dysgeusia affects people in different ways. In general, food just doesn’t taste the same as you remember. Some common symptoms are:

All foods taste metallic or bitter.
Foods that are characteristically sweet or salty no longer taste sweet or salty.
Foods that used to taste good now taste bad, and sometimes rotten.
There’s a nasty taste in your mouth even though you haven’t eaten anything.

What causes dysgeusia?

Many things may cause this condition, including:

Aging. Your sense of taste changes as you age.
Medications. Many medications can affect your sense of taste. Some examples include over-the-counter allergy medications, and prescription drugs like antibiotics, antidepressants, and chemotherapy drugs.
Dental prostheses. If you need prostheses that cover your soft palate, these devices can affect your taste receptors so food tastes different.
Poor oral hygiene.
Using tobacco.
Certain medical conditions.

Medical conditions

Several conditions can cause dysgeusia, including:

Dry mouth (xerostomia). This happens when your salivary glands produce less saliva because you’re not drinking enough fluid.
GERD (chronic acid reflux). When stomach acid enters your mouth, it can affect your taste function. For this reason, some people with GERD develop dysgeusia.
Head and neck cancers. Cancer and cancer treatments like chemotherapy or radiation therapy may affect your sense of taste.
Infections. Viral infections like colds, flu or COVID-19 affect your sense of taste.
Inflammation. Any condition that results in inflammation of your tongue can affect your taste receptors and your sense of taste.
Metabolic disorders. Diabetes, hypothyroidism, kidney disease, liver disease and other metabolic conditions can cause dysgeusia.
Nerve damage. You have nerves that manage taste sensation. When something damages these nerves, like ear or neck surgery, they don’t work like they should, causing dysgeusia.
Neurologic disorders. Alzheimer’s disease, Parkinson’s disease and multiple sclerosis (MS) have been associated with dysgeusia.
Pregnancy. Dysgeusia during pregnancy is common, usually due to a surge of hormones. Symptoms typically go away on their own after the first trimester.
Traumatic brain injury (TBI). If you have a TBI that damages the lining of your nose, your olfactory nerve or the part of your brain that processes your sense of taste, that can cause dysgeusia.
Vitamin or mineral deficiencies. People who have zinc or vitamin B deficiencies are especially prone to dysgeusia.

Diagnosis and Tests

How is dysgeusia diagnosed?

Your healthcare provider will do a physical examination and ask about your symptoms. They may do the following tests:

A smell identification test. Your sense of taste and smell have a lot in common. Your provider may do a smell identification test to rule out anosmia (loss of sense of smell).
Taste threshold tests. These tests show when you detect changes in how food tastes.
Blood tests. Your provider may order a complete blood count (CBC) and tests to check your levels of potassium, calcium, iron and vitamin B12.
Imaging tests. Sometimes, abnormal growths or physical changes can affect your sense of taste. Your provider may order tests including X-rays, computed tomography (CT) scans or magnetic resonance imaging (MRI) scans.

Management and Treatment

How is dysgeusia treated?

Treatment depends on why you have dysgeusia. For example, if medication is causing dysgeusia, changing medications may help. If you have a viral infection like COVID-19 that affects your sense of smell and taste, your healthcare provider may recommend olfactory training therapy.

Studies show your sense of smell is responsible for about 80% of what you taste. Your nose and throat share the same airway, so chewing some foods allows food aroma to make its way to your nose through the back of your mouth. Olfactory training therapy involves daily exposure to different odors for several weeks. Over time, what you smell stimulates your olfactory system in your brain and re-establishes your memories of that smell.