Why Do My Teeth Hurt? Understanding the Causes and Solutions of Dental Pain

Tooth Pain Points to an Irritated Structure

Tooth pain is a symptom. It tells you that one of the structures in and around the tooth, the enamel, the dentin beneath it, the pulp at its centre, the gum and bone that hold it, or a neighbouring area such as the maxillary sinus, has been irritated, injured or infected. The pain can arrive suddenly or build over weeks, and it can feel like a dull ache, a sharp zing or a throbbing that keeps you awake.

The possible causes include decay, gum disease, an abscess, a crack, an impacted wisdom tooth, orthodontic movement, a recent filling, grinding, sinus infection, acid erosion, hormonal change and nutritional deficiency. Each has its own treatment. Decay needs a filling, grinding needs protection for the teeth, and pain driven by the sinus settles when the sinus is treated.

This is why the trigger matters as much as the pain itself. A short, sharp response to cold that fades within seconds usually comes from exposed dentin. A deep ache that lingers after the cold is gone, or that wakes you at night, suggests an inflamed pulp. Pain on biting points to one tooth and a mechanical problem, while an ache spread across many teeth points away from any single tooth. Noting when the pain starts, how long it lasts and what sets it off gives the dentist a head start in the examination.

Decay, Sensitivity and Enamel Erosion

Tooth decay is one of the most frequent causes of tooth pain. Plaque bacteria turn sugars into acid that dissolves enamel. Early decay is often painless; once it reaches the dentin, the tooth reacts to sweets, cold and heat, and if it reaches the pulp the pain becomes deeper and longer.

Dentin hypersensitivity produces a similar sharp zing without a cavity. Worn enamel or gum recession exposes the dentin, so cold drinks, sweet or acidic food and even brushing trigger a brief, sharp pain. It is common. A meta-analysis of 77 studies reported in 65 papers put the pooled prevalence of dentin hypersensitivity at 11.5%, with an unweighted average across studies of 33.5% (PubMed 30639724). Individual studies ranged from 1.3% to 92.1%, with higher figures in specialty practice patients and younger adults (PubMed 30639724).

Enamel erosion adds to both problems. Citrus fruit, soda, energy drinks and stomach acid in people with reflux soften and thin the enamel over time, bringing dentin closer to the surface. Erosion often affects many teeth at once, which is why it can feel like general sensitivity across the mouth.

A single tooth that reacts to sweets is more likely to have decay or a failing filling. Sensitivity spread across several teeth near the gumline fits exposed dentin or erosion better.

Gum Disease, Abscesses and Cracked Teeth

Gum disease causes pain in a different way. Gingivitis, the early stage, brings swollen, red gums that bleed on brushing and are often only mildly sore. As it progresses to periodontitis, supporting bone is lost, pockets form between gum and tooth and the gumline recedes. Teeth can ache, feel tender to bite on and eventually loosen, often with bad breath.

A dental abscess is a pus-filled infection inside the tooth or in the gum beside it. It usually follows deep decay, a crack that lets bacteria into the pulp, or advanced gum disease. The pain is severe, persistent and often throbbing, and swelling in the face or jaw, fever and a foul taste can come with it. An abscess needs prompt treatment, because the infection can spread into the surrounding bone and soft tissue.

Cracked teeth hurt in a characteristic way. Even a fine crack can cause a sharp pain when you bite down, sometimes with a second sting when you release. The crack may be invisible and the tooth can feel normal between meals. Grinding, chewing ice or other hard objects and trauma are the usual causes, and large fillings make cracks more likely.

These conditions can overlap. A crack can let bacteria reach the pulp and turn into an abscess, so a tooth that hurts on biting and has started to swell should be examined quickly.

Wisdom Teeth, Braces and Pain After Treatment

Wisdom teeth that cannot erupt properly because of limited space are called impacted. They can press against the second molar, trap food under a flap of gum and become inflamed. The pain sits at the back of the mouth and may spread to the jaw, ear or head, with swelling and difficulty opening the mouth wide.

Orthodontic treatment causes a different kind of discomfort. Braces and aligners move teeth with steady pressure, and the ligament around each tooth becomes tender while it adapts. The soreness is usually strongest in the first days after an appliance is fitted or adjusted, affects several teeth together and feels like pressure.

Some people notice temporary pain after a filling, a crown or root canal treatment. The nerve inside the tooth can be irritated by the procedure, a new filling or crown may sit slightly high and take extra load when you bite, or the tissues around the treated tooth can stay inflamed for a few days.

Mild tenderness that improves day by day is expected. Pain that grows stronger, a bite that feels uneven, or pain that returns after it had settled deserve a follow-up visit. A high filling or crown can be adjusted in minutes, and persistent pain after root canal treatment needs an examination to check for remaining infection.

Grinding, Clenching and Sinus Pressure

Some tooth pain has no single diseased tooth behind it. Bruxism, the involuntary grinding or clenching of the teeth, loads every tooth and the jaw muscles well beyond normal chewing forces, during sleep or during the day and often under stress. Typical signs are jaw soreness on waking, flattened or chipped tooth surfaces and frequent headaches.

Bruxism is common. A systematic review of global data found an overall bruxism prevalence of 22.22%, with sleep bruxism at 21% and awake bruxism at 23% (PubMed 39064299). The review concluded that one in four individuals may experience awake bruxism (PubMed 39064299). Because the load is spread across the mouth, grinding often makes many teeth ache at once.

Sinus infection is the usual reason teeth hurt when you are unwell. The roots of the upper back teeth sit close to the floor of the maxillary sinuses, so when the sinus lining swells during a cold, the pressure is felt in those teeth. The clue is several upper molars aching together, with congestion and facial pressure that may worsen when you bend forward. Dehydration, a dry mouth and fever-related clenching can add to it.

Sinus-related tooth pain eases as the infection clears. If the pain stays in one tooth after the congestion has gone, the tooth itself needs to be examined.

Hormonal Change and Nutritional Deficiencies

Hormonal fluctuations affect the gums. During pregnancy, around menstruation and at menopause, some people notice gums that swell, bleed more easily and feel sore, because the tissue reacts more strongly to the same amount of plaque. Careful daily cleaning and a check-up during pregnancy help keep this under control.

Nutritional deficiencies can also show up in the mouth. A lack of vitamin C, vitamin B12, iron or calcium can compromise the health of the gums and the lining of the mouth, with bleeding gums, recurring mouth ulcers and, in advanced cases, loosening teeth.

For recurrent aphthous ulcers, the link with deficiencies has been measured. A meta-analysis of nine case-control studies, with 710 cases in the ulcer groups and 602 in the control groups, found deficiencies significantly more often in people with recurrent ulcers (PubMed 25720915). The combined odds ratios were 3.75 for vitamin B12, 7.55 for folic acid, 2.62 for ferritin and 1.77 for haemoglobin (PubMed 25720915).

These are associations from case-control studies. They show that people with recurrent ulcers are more likely to have low levels, and they leave open whether a given ulcer comes from a deficiency. When ulcers keep returning or gums bleed without an obvious cause, a blood test arranged with your doctor can clarify the picture.

Relief at Home and Treatment of the Cause

Home measures make the wait for an appointment easier. Over-the-counter pain relievers taken as directed, a cold compress on the outside of the jaw and warm salt water rinses ease most dental pain. Avoiding very hot, very cold and sugary food keeps the painful tooth from being provoked. These steps hold the symptoms for a while; the cause still needs treatment.

Long-term solutions depend on the diagnosis. Decay is removed and filled, and decay or infection that has reached the pulp is treated with a root canal. Sensitivity from exposed dentin often improves with desensitising toothpaste used for several weeks. Gum disease is treated with professional cleaning below the gumline and better home care. Antibiotics have a role in spreading infections, alongside treatment of the tooth that caused them.

For grinding, a custom-made night guard protects the teeth from the forces of sleep bruxism. Because stress often drives clenching, regular physical activity, relaxation techniques or meditation address the source as well as the symptom.

Prevention covers most of these causes at once. Brushing twice a day with fluoride toothpaste and a soft brush, cleaning between the teeth, limiting sugary and acidic food and drink, and regular check-ups reduce the risk of decay, gum disease and erosion.

Signs That Need a Dental Examination

Some tooth pain settles by itself, such as mild tenderness after a filling or soreness during a cold. Other pain signals a problem that needs treatment to resolve. The threshold for booking an appointment is concrete. See a dentist if the pain lasts more than one to two days, if it is severe or throbbing, if it comes with swelling or fever, or if there is visible damage to a tooth.

Swelling in the face or jaw, fever, difficulty swallowing or opening the mouth, and a bad taste that suggests pus point to an infection that can spread and need attention the same day where possible. Pain that wakes you at night or lingers long after a hot or cold drink suggests the pulp is involved.

At the examination, the dentist asks when the pain started, what triggers it and how long it lasts, then tests the teeth with cold and pressure and takes X-rays where needed. Bringing notes on your pain pattern, recent dental work, grinding habits, sinus symptoms and medicines makes the diagnosis quicker, and the treatment options and number of visits can then be discussed for your situation.