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.

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.

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

Assigned females experience hormone changes throughout their lives that can cause taste changes. These include:

• 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.

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 by triggering your body's stress response. They can also make your mouth dry.

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 like epilepsy, multiple sclerosis, Bell's palsy, brain tumors, and dementia can also change your sense of taste.

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. At least 250 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

Some of the more common medications that can cause a sour taste in your mouth include:

• Antibiotics: Including ampicillin, macrolides, quinolones, sulfamethoxazole, trimethoprim, tetracycline, and metronidazole
• Heart medications: Including many high blood pressure medications, diuretics, statins, and antiarrhythmics
• Chemotherapy drugs: Including cisplatin, cyclophosphamide, and etoposide
• Neurologic medications: Including antiparkinson drugs, migraine medications, and muscle relaxants
• Psychotropic drugs: Including most tricyclic antidepressants, some antipsychotics, anti-anxiety drugs, mood stabilizers, and hypnotics
• Other prescription and over-the-counter (OTC) drugs: Including thyroid drugs, antihistamines, bronchodilators, anti-inflammatories, smoking cessation aids, antifungals, and antivirals
  

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.

For example:

• 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.

Strategies Anyone Can Use

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.