7 Reasons Behind Sour or Bitter Taste in Your Mouth

Medically reviewed by
Dr. Vinita Tekchandani, Masters degree in Oral & Maxillofacial Pathology
Maharashtra Dental Council Registration No. (A-21799 MSDC)

Date : 10 March 2023

Do you frequently notice a bitter or sour taste in your mouth, even when you have not eaten anything with a strong flavour? An occasional unpleasant taste after drinking coffee or eating certain foods is usually normal. However, a taste that persists or keeps returning may be related to your oral health, medications or another underlying condition.

A persistent unpleasant taste can be described as dysgeusia, a change in the way you perceive taste. It may occur alongside dry mouth, bad breath, acid reflux, gum problems or changes in your sense of smell.

In this blog, we explain seven possible causes of a bitter or sour taste in your mouth, what you can do to manage it, and when to consult a dentist or doctor.

What Are the Most Common Causes of a Bitter or Sour Taste in Your Mouth?

Several factors can change how food and drinks taste. The following are seven possible causes to consider.

1. Can Smoking Cause a Bitter or Sour Taste in Your Mouth?

Yes. Smoking can affect your sense of taste and smell. Tobacco exposure may also contribute to dry mouth, gum disease and other oral health problems, which can leave an unpleasant taste.

Smoking can reduce your ability to enjoy flavours normally, while plaque accumulation and gum inflammation may contribute to bad breath and a persistent taste in the mouth.

What can help?

• Consider a plan to stop smoking or using tobacco.
• Brush twice daily with fluoride toothpaste.
• Clean between your teeth every day.
• Visit your dentist if you notice bleeding gums, persistent bad breath or an unpleasant taste that does not improve.

2. Can Dry Mouth Cause a Bitter Taste?

Yes. Saliva helps keep the mouth moist, remove food particles and maintain a healthy oral environment. When saliva production decreases, you may experience a sticky feeling, difficulty tasting food, bad breath or a bitter or sour taste.

Dry mouth, also known as xerostomia, can be caused by dehydration, certain medicines, mouth breathing and some medical conditions. Persistent dry mouth can also increase the risk of tooth decay and oral infections.

What can help?

• Sip water regularly throughout the day.
• Try sugar-free chewing gum if it is suitable for you.
• Avoid tobacco and limit alcohol if they worsen dryness.
• Ask your dentist or doctor about saliva substitutes or other treatments if the problem continues.

Do not assume that dry mouth is caused only by insufficient water intake. Persistent dryness may need further assessment.

3. Can Medicines Cause an Unpleasant Taste in the Mouth?

Yes. Certain medicines can change your sense of taste or reduce saliva production. Some antibiotics, antihistamines and other prescription or over-the-counter medicines may contribute to an unpleasant, bitter or metallic taste.

The effect varies depending on the medicine and the individual. Sometimes the taste change begins after starting a new medicine or changing a dose.

What can help?

• Note when the taste change started and whether it coincided with a new medicine.
• Tell your doctor or pharmacist about the symptom.
• Do not stop or change a prescribed medicine without professional advice.

If a medication is responsible, your clinician can decide whether a suitable alternative or other adjustment is appropriate.

4. Can Poor Oral Hygiene Cause a Bitter or Sour Taste?

Yes. Plaque, food debris, gum inflammation, tooth decay and some oral infections can contribute to an unpleasant taste or bad breath.

Bacteria in dental plaque can contribute to gum disease and tooth decay. If you have bleeding gums, swollen gums, toothache or persistent bad breath alongside a bitter taste, a dental problem may be responsible.

What can help?

• Brush your teeth twice daily with fluoride toothpaste.
• Clean between your teeth daily using floss or an appropriate interdental brush.
• Gently clean your tongue.
• Arrange a dental examination if the taste continues or you notice other oral symptoms.

Professional cleaning may be needed to remove hardened plaque, known as tartar. Mouthwash alone cannot treat every cause of an unpleasant taste.

5. Can Dehydration Cause a Bitter or Sour Taste?

Yes. Dehydration can reduce saliva production, making your mouth feel dry and affecting your perception of taste. You may also notice thirst, darker urine or reduced urination, depending on the degree of dehydration.

Dehydration can occur during hot weather, after heavy exercise, or when you lose fluids through vomiting or diarrhoea.

What can help?

• Drink water regularly and increase fluid intake when you are losing more fluid than usual.
• Avoid relying heavily on alcohol or excessive caffeine if these worsen your symptoms.
• Seek medical advice if you cannot keep fluids down or have signs of significant dehydration.

If the unpleasant taste continues despite adequate hydration, another cause may need to be investigated.

6. Can Pregnancy Cause a Bitter or Metallic Taste in the Mouth?

Yes. Some people experience changes in taste during pregnancy, including a metallic, bitter or unusual taste. Hormonal changes may contribute. Pregnancy can also increase the likelihood of acid reflux, which may cause a sour taste.

The timing and duration of taste changes vary. It is not accurate to say that every pregnancy-related taste change will disappear at a specific time.

What can help?

• Drink water regularly.
• Maintain gentle, consistent oral hygiene.
• Notice whether particular foods or drinks trigger the taste.
• Discuss persistent symptoms with your maternity care provider or dentist, especially if you also have vomiting, reflux or dental concerns.

Check with your healthcare professional before using medicines or supplements to treat taste changes during pregnancy.

7. Can Zinc Deficiency Affect Your Sense of Taste?

Yes. Zinc is an essential mineral involved in several body functions, including normal taste and smell. Zinc deficiency can contribute to altered taste, although a bitter or sour taste alone does not confirm a deficiency.

Changes in taste may also occur with other nutritional deficiencies, infections, medication effects and oral health problems.

What can help?

• Maintain a balanced diet that includes suitable sources of zinc, such as beans, nuts, dairy products, eggs, meat or seafood, depending on your diet.
• Ask a healthcare professional whether testing is appropriate if you have additional symptoms or risk factors.
• Avoid taking high-dose zinc supplements without medical advice, as excessive zinc can cause adverse effects and interfere with copper absorption.

How Can You Get Rid of a Bitter or Sour Taste in Your Mouth?

The best way to manage a persistent unpleasant taste is to address its cause. In the meantime, these measures may help:

• Maintain oral hygiene: Brush twice daily with fluoride toothpaste and clean between your teeth.
• Clean your tongue gently: Remove surface debris without scraping aggressively.
• Stay hydrated: Drink water regularly, particularly if your mouth feels dry.
• Avoid tobacco: Smoking can affect taste and oral health.
• Identify triggers: Notice whether certain foods, medicines or situations make the taste worse.
• Manage reflux if present: Follow advice from your healthcare professional.
• Review medications: Ask your prescriber whether a medicine may be contributing.

Final Thoughts:

A bitter or sour taste in your mouth can result from several factors, including dry mouth, dehydration, smoking, medication side effects, poor oral hygiene, pregnancy-related changes, nutritional deficiencies and acid reflux.

Maintaining good oral hygiene and staying hydrated may help, but persistent symptoms should not be ignored. A dental or medical examination can help identify the underlying cause and guide appropriate treatment.

If you are experiencing an unpleasant taste along with bleeding gums, tooth pain, bad breath or other oral health concerns, arrange a dental check-up to discuss your symptoms.