A Bad Taste in Your Mouth That Will Not Go Away

By Lovik Mirzaeian, DDS. Updated October 2026.

A bad taste in your mouth that will not go away is most often caused by gum disease, a hidden infection, dry mouth, acid reflux, post-nasal drip from the sinuses, or a medication you take every day. Brushing and mouthwash mask it for an hour and then it returns, because they do not reach the source. Finding the source is the only real fix, and it usually takes a dental exam plus some detective work about your health and habits.

Patients often apologize when they bring this up, as though it is a hygiene failing. It usually is not. It is a symptom.

First, Describe the Taste

The flavor itself is a clue. A metallic taste points toward bleeding gums, a corroded filling, or certain medications, and we covered that in detail in our post on the dental causes of a metallic taste. A sour or acidic taste, especially in the morning, points toward reflux. A bitter taste is common with dry mouth and with some drugs. A foul, rotten taste suggests infection or trapped food. A salty taste can come from post-nasal drip or dry mouth.

Also note the timing. Worst on waking suggests dry mouth, mouth breathing, or reflux overnight. Worst after meals suggests food trapping or reflux. Constant and unchanging suggests a medication or a persistent infection.

Gum Disease

The most common dental cause is gum disease that has moved beyond simple gingivitis. As the gums pull away from the teeth, pockets form, and those pockets fill with bacteria that produce sulfur compounds. The result is a taste and a smell that no amount of brushing reaches, because the bristles cannot get four millimeters below the gumline.

The signs are bleeding when you brush or floss, red or swollen gums, and teeth that feel slightly loose. Treatment is a deep cleaning to clear the pockets, followed by better home care and more frequent maintenance visits. The taste usually improves within a couple of weeks of the pockets being cleaned.

A Hidden Infection

A tooth with a dead nerve, a cracked tooth, an infected wisdom tooth, or a failing root canal can all leak infection into the mouth slowly, through a tiny opening in the gum, without much pain. Patients describe a bad taste that comes and goes, sometimes with a small salty burst when they press on a spot on the gum. That spot is a drainage point, not a sign of healing.

This needs treatment, usually a root canal or an extraction, and antibiotics alone will not fix it. If you have a bump on the gum, a tooth that is tender to bite on, or swelling, read our guide to abscess signs and when to go now.

Dry Mouth

When saliva runs low, food debris and bacteria build up on the tongue and between the teeth, and the taste turns stale, bitter, or sour. Dry mouth is most often caused by medications, including blood pressure drugs, antidepressants, antihistamines, and decongestants. Mouth breathing at night, dehydration, diabetes, and some autoimmune conditions add to it.

If your mouth feels sticky when you wake and the bad taste is strongest in the morning, dry mouth is a likely culprit. Our post on why your mouth is so dry when you wake up covers what helps, and a fluoride rinse designed for dry mouth is a better choice than an alcohol-based mouthwash, which dries the mouth further.

Acid Reflux

Stomach acid that travels up the esophagus at night reaches the back of the throat and the mouth, leaving a sour or bitter taste on waking and sometimes a burning throat or a hoarse voice. Many people with reflux never feel heartburn; the taste is the only sign. Over time reflux also erodes the enamel on the inside of the upper teeth, which I often see before the patient has any idea it is happening.

If the taste is sour and worst in the morning, and especially if your enamel shows that pattern of wear, it is worth talking to your physician about reflux. Raising the head of the bed, avoiding late meals, and cutting back on evening alcohol and coffee help many people in the meantime.

Sinuses, Medications, and Everything Else

A sinus infection or chronic allergies produce mucus that drains down the back of the throat, and that drainage tastes bad. It often comes with a stuffy nose, pressure around the cheeks, and bad breath that seems to come from the throat rather than the mouth. Upper back teeth can ache with sinus pressure, which sometimes sends people to the dentist first. That is a job for your doctor, though we can rule the teeth out.

Dozens of common drugs alter taste directly, not just by drying the mouth. If the taste started within a few weeks of a new prescription, mention it to the prescribing doctor. Less common causes include a coated tongue that has never been cleaned, oral thrush, a nutritional deficiency, hormone shifts in pregnancy, and, rarely, nerve or systemic conditions. The American Dental Association has a useful overview of the causes of persistent bad breath, most of which overlap with bad taste.

What to Do This Week

Brush twice a day, clean your tongue every time, and floss once a day. Drink water steadily. Skip alcohol-based mouthwash. Note when the taste is worst. If two weeks of this has not helped, it is time to be seen. Our post on why your breath smells even after brushing covers the tongue-cleaning technique that makes the biggest difference.

When to See a Dentist

A bad taste that has lasted more than two weeks deserves a routine dental exam, where we check the gums, every tooth, and any old dental work, and take x-rays to look for infection you cannot feel. If the mouth is healthy, we will say so and point you to your physician for reflux, sinus, or medication causes. A bad taste with swelling, a throbbing tooth, or fever is urgent, so call the same day.

Frequently Asked Questions

Why do I have a bad taste in my mouth that will not go away?

The most common causes are gum disease, a low-grade tooth infection, dry mouth, acid reflux, sinus drainage, or a medication side effect. Brushing and mouthwash only mask these for a short time. A dental exam can find or rule out the mouth-related causes.

What does a bad taste in the mouth from infection taste like?

Usually foul, rotten, or salty, and it may come and go, sometimes with a small burst of fluid when you press on a spot on the gum. A tooth that is tender to bite on, a pimple-like bump on the gum, or swelling alongside the taste points to infection and needs prompt treatment.

Can acid reflux cause a bad taste in the mouth?

Yes. Acid that travels up during the night leaves a sour or bitter taste on waking, often with a burning throat or hoarse voice, and many people with reflux never feel heartburn. Reflux also wears the enamel on the inside of the upper teeth, which a dentist can spot.

How do I get rid of a bad taste in my mouth?

Brush twice a day, clean your tongue, floss daily, drink water regularly, and avoid alcohol-based mouthwash. If the taste persists beyond two weeks, see a dentist to check for gum disease, infection, and dry mouth, and see a physician if the mouth is healthy.

Tired of That Taste? Dr. Mirzaeian Can Help

A persistent bad taste almost always has a cause we can find, and the dental ones are usually fixable within a visit or two. If it has been hanging around, contact us to set up a consultation and we will get to the bottom of it.

Lovik Mirzaeian, DDS has achieved extensive training in multidisciplinary dental treatments. His credentials include Dental Implants, Cosmetic Dentistry, Full Mouth Reconstruction, Endodontics, Oral Surgery, Orthodontics, and Sleep Sedation. Our office puts your comfort and smile first, and we are dedicated to giving you top-notch dental care. Get ready to show off your perfect smile!

Looking for a trusted family dentist in Clovis? Dr. Mirzaeian welcomes new patients of all ages.