Tooth pain has dozens of possible causes, ranging from temporary sensitivity to serious infection. About 41% of adults report experiencing some degree of dental pain within a six-month period, so if your teeth hurt, you’re far from alone. The key to figuring out what’s going on is paying attention to the type of pain you’re feeling, when it happens, and how long it lasts.
Sensitivity to Hot or Cold
A quick, sharp zing when you sip iced coffee or bite into something hot is usually dentin hypersensitivity. Your teeth have a hard outer layer (enamel) that protects a softer inner layer called dentin. Dentin contains thousands of microscopic tubes that lead toward the nerve at the center of the tooth. When enamel wears down or your gums recede, those tubes become exposed. Temperature changes cause fluid inside the tubes to shift, which triggers the nerve and produces that familiar jolt of pain.
This type of sensitivity is common after whitening treatments, after eating acidic foods, or if you brush too aggressively with a hard-bristled toothbrush. It can also develop gradually as gums pull back with age. The pain is brief, disappearing within a second or two once the hot or cold stimulus is gone. If it lingers longer than a few seconds, something more serious may be happening inside the tooth.
Cavities and Tooth Decay
Cavities are the most familiar cause of tooth pain. Bacteria in your mouth feed on sugars and produce acid that gradually dissolves enamel. Once that acid eats through enough of the outer layer, it reaches the sensitive dentin underneath, and eventually the nerve-rich pulp at the tooth’s core. Early cavities often cause no pain at all, which is why they’re easy to miss. By the time a cavity hurts, it’s usually progressed well past the surface.
Cavity pain tends to show up as sensitivity to sweets, cold drinks, or pressure when chewing. You might notice it only with certain foods at first. As the decay deepens, the pain becomes more frequent and harder to ignore. A dark spot or visible hole on a tooth is an obvious sign, but many cavities form between teeth where you can’t see them.
Inflamed or Infected Pulp
The pulp is the living tissue inside your tooth that contains nerves and blood vessels. When decay, a crack, or repeated dental work irritates the pulp, it becomes inflamed, a condition called pulpitis. There are two stages, and the difference between them matters a lot.
In the earlier, reversible stage, you’ll feel sensitivity to cold or sweets that fades quickly once the trigger is removed. Tapping the tooth won’t produce pain. At this point, the tooth can still recover with treatment. In the later, irreversible stage, the pain lingers for more than a few seconds after exposure to hot, cold, or sweet stimuli. Tapping on the tooth hurts. You may feel a deep, throbbing ache that comes on without any trigger at all, sometimes waking you at night. At this stage the pulp is too damaged to heal on its own, and a root canal or extraction is typically needed.
The main signal that things have crossed from reversible to irreversible is lingering sensitivity to heat. If a sip of hot tea causes pain that sticks around well after you’ve swallowed, that’s a red flag.
Cracked or Fractured Teeth
A cracked tooth can be surprisingly hard to diagnose because the pain is erratic. You might feel a sharp stab when biting down on something, then nothing at all for days. One hallmark sign is pain that hits not when you bite down but when you release the bite. That happens because chewing forces the cracked pieces apart, irritating the pulp inside.
Cracks don’t always show up on X-rays, which makes them tricky. They can result from chewing ice or hard candy, from a blow to the face, or from years of grinding. If you notice inconsistent pain tied to chewing, especially pain on release, a crack is a strong possibility.
Teeth Grinding
If your teeth feel sore when you wake up, with pain spread across several teeth rather than focused on one, grinding (bruxism) is a likely culprit. Nighttime grinding is especially damaging because you can’t consciously stop it, and the forces involved are much greater than during normal chewing.
Over time, grinding wears down enamel, loosens teeth, and can create tiny fractures across the biting surfaces. Common symptoms include morning headaches or facial pain, a sore jaw, earaches, ringing in the ears, and difficulty opening your mouth wide. You might not realize you’re doing it until a dentist notices the wear patterns on your teeth or a partner hears the sound at night. A custom night guard is the most common solution, protecting your teeth from the pressure while you sleep.
Sinus Pressure and Referred Pain
Not all tooth pain actually comes from your teeth. Your largest sinus cavities sit directly above the roots of your upper back teeth. In some people, the tooth roots actually extend into the sinus cavity. When those sinuses become inflamed from a cold, allergies, or a sinus infection, the pressure can feel exactly like a toothache in your upper molars.
The giveaway is usually the pattern. Sinus-related tooth pain affects multiple upper teeth at once rather than a single tooth. It gets worse when you bend forward or lie down, and it often comes with nasal congestion, facial pressure, or a headache across your forehead and cheeks. If treating the sinus issue resolves the tooth pain, the teeth themselves were never the problem.
Gum Disease
Sometimes what feels like tooth pain is actually coming from the gums. Early gum disease (gingivitis) causes redness, swelling, and bleeding when you brush. As it advances to periodontitis, the gums pull away from the teeth and form pockets that trap bacteria. This can make teeth feel tender, loose, or achy, especially when chewing. You might also notice persistent bad breath or a bad taste in your mouth.
Gum disease progresses slowly and painlessly for a long time, which is why it often goes undetected. By the time it hurts, the supporting bone around the teeth may already be breaking down.
Managing Pain at Home
While you’re waiting to get to a dentist, a combination of ibuprofen and acetaminophen taken together is more effective for dental pain than either one alone. Research from Harvard Health found this combination outperformed even opioid painkillers after dental surgery. You can take both at the same time, repeating every four to six hours as needed.
Applying a cold compress to your cheek in 15-minute intervals can reduce swelling and numb the area. Rinsing with warm salt water helps keep the area clean if there’s an infection brewing. Avoid very hot, very cold, or sugary foods and drinks that could intensify the pain.
Signs the Pain Is Urgent
Most tooth pain deserves a dental visit within a few days, but certain symptoms signal something more serious. Swelling in your jaw or face, especially if it’s spreading, means an infection may be moving beyond the tooth. A fever, swollen lymph nodes, or earache alongside tooth pain are signs the infection is becoming systemic. Pain severe enough to prevent you from sleeping, eating, or functioning normally counts as a dental emergency.
Swelling that makes it hard to breathe or swallow requires immediate hospital care, not just a dentist. An untreated dental abscess can spread to the throat, chest, or brain, so facial swelling paired with fever is never something to wait out.