What Causes a Toothache?

Tooth Decay (Cavities)

Cavities are among the most common causes of toothache. Tooth decay starts when bacteria in plaque create acids that weaken enamel. Early cavities may not hurt at all. But as decay moves deeper – toward the dentin and the nerve (pulp) – pain and sensitivity become more likely.

Common clues that it may be a cavity:

• Sensitivity to sweets, cold drinks, or hot foods

• A “zing” of pain that lingers after temperature changes

• Pain when biting in one specific spot

• A visible hole, dark spot, or rough area on the tooth

When tooth decay progresses, it can lead to inflammation of the nerve or a dental infection. If you suspect a cavity is behind your pain, an urgent evaluation can help identify how deep the decay is and what needs to be addressed. You can learn more about urgent evaluation options through exams and X-rays.

Gum Disease and Receding Gums

Not all toothaches start in the tooth itself. Gum irritation and gum disease can cause soreness, tenderness, and even sharp pain, especially if the gums have receded, exposing the root surface.

How gum-related pain may present:

• Generalized tenderness around multiple teeth

• Bleeding when brushing or flossing

• Swollen gums, “puffy” tissue, or gumline sensitivity

• Pain that worsens with brushing, flossing, or chewing

Receding gums can expose root surfaces that don’t have the same protective enamel as the crown of the tooth, making teeth more sensitive and vulnerable. Gum disease can also contribute to pockets of infection around teeth that mimic a toothache.

Tooth Trauma or Injury

A chipped, cracked, or broken tooth can trigger sudden pain, even if the damage seems minor. Trauma can expose dentin, irritate the nerve, or create micro-cracks that hurt when you bite down.

Possible causes include:

• Biting on something hard (ice, popcorn kernels, hard candy)

• Sports injuries or falls

• Accidents that loosen a tooth or damage a restoration

• Previously weakened teeth with large fillings

Signs trauma may be the cause:

• Pain when chewing that comes and goes

• Sensitivity to cold air or cold drinks

• A rough edge you can feel with your tongue

• A tooth that feels “different” when you bite

Even small fractures can allow bacteria to enter deeper layers of the tooth. If you’ve had an injury, it’s important not to ignore persistent pain, especially if it worsens over time.

Teeth Grinding (Bruxism)

Grinding or clenching (often during sleep) can strain teeth and the muscles/joints that move the jaw. Over time, that pressure can cause tooth soreness, enamel wear, small cracks, and heightened sensitivity.

Clues that bruxism may be involved:

• Morning jaw soreness or fatigue

• Headaches that feel like tension headaches

• Teeth that look flattened or worn

• Tooth pain without an obvious cavity

Grinding can also aggravate existing dental problems (like a cracked filling or a vulnerable tooth), making it feel like a “new” toothache when it’s actually an older issue that’s been pushed over the edge.

Wisdom Teeth Problems

Wisdom teeth can cause pain when they’re erupting, crowding, partially trapped under the gum, or difficult to keep clean. Food and bacteria can get trapped around a partially erupted wisdom tooth, irritating gum tissue and triggering inflammation.

What wisdom-tooth-related pain may feel like:

• Soreness in the back of the mouth

• Gum swelling or tenderness behind molars

• Pain when chewing on that side

• A bad taste or persistent irritation near the back gumline

Wisdom tooth pain can overlap with other conditions (like decay on the neighboring molar), so evaluation is important if symptoms persist.

Dental Infections and Abscesses

When bacteria reach the tooth’s inner tissues or spread beyond the root tip, pressure and inflammation can build quickly. An abscess is a pocket of infection that can cause significant pain and swelling.

Common infection/abscess warning signs:

• Severe, persistent toothache (often throbbing)

• Swelling of the gums, cheek, or jaw

• A pimple-like bump on the gum (possible drainage)

• Pain that radiates to the ear, jaw, or neck

• Fever or feeling generally unwell

• Tender or enlarged lymph nodes

Dental infections don’t usually resolve on their own. If you suspect an infection, especially if it’s accompanied by swelling, seek prompt care. Urgent Dental Care provides services for dental infection concerns and can evaluate symptoms to determine what’s driving the pain.

Dry Socket After Extraction

A toothache can also occur after a tooth has been removed.

Common dry socket clues:

• Pain that worsens a few days after extraction (often days 2-4)

• Pain that radiates toward the ear or jaw

• Bad breath or unpleasant taste

• The extraction site looks “empty” or has visible bone

Dry socket pain is often more intense than expected after an extraction and typically needs professional management for relief. If post-extraction pain suddenly worsens, don’t wait – an evaluation can help determine whether it’s dry socket or something else. See more on dry socket concerns.