A toothache has a way of taking over your entire day. A small twinge while drinking cold water can quickly turn into throbbing pain that makes eating, sleeping, and concentrating difficult.
So, what causes a toothache? Dental pain can come from tooth decay, an infection, gum disease, a cracked tooth, a damaged filling, or pressure from an erupting wisdom tooth.
Teeth grinding and sensitivity may also cause discomfort, while some pain that feels dental actually begins in the sinuses, jaw muscles, or facial nerves.
The type of pain may offer clues, but it cannot provide a reliable diagnosis on its own. A sharp reaction to cold, for example, could come from decay, exposed dentin, gum recession, or a crack.
Understanding the common causes of tooth pain can help you recognize when a problem needs routine care and when it requires urgent dental treatment.
What Is a Toothache?
A toothache is pain felt in or around a tooth. It may be sharp, dull, throbbing, constant, or triggered by biting, temperature changes, or sweet foods.
Pain develops when sensitive tissues become irritated or inflamed. The outer enamel does not contain nerves, but the dentin beneath it contains microscopic channels connected to the dental pulp.
The pulp contains nerves and blood vessels, so deeper damage can cause stronger or longer-lasting discomfort.
Some toothaches are temporary, such as mild gum irritation caused by trapped food. Others indicate a problem that will not heal without dental care, including a cavity, fracture, or bacterial infection.
Tooth Decay Is a Common Cause
Tooth decay begins when bacteria in dental plaque use sugars and starches to produce acids. Repeated acid attacks remove minerals from enamel and may eventually create a cavity.
Early decay often causes no symptoms. As it moves deeper, the tooth may become sensitive to sweet, hot, or cold foods. A larger cavity can cause spontaneous aching, pain when chewing, or discomfort that continues after the trigger has disappeared.
For example, a quick sensation after eating ice cream may suggest mild sensitivity. Pain that lingers or becomes stronger over time is more concerning because decay may have reached the dentin or irritated the pulp.
Once a physical hole has formed, brushing cannot close it. The damaged area usually needs professional treatment, such as a filling, crown, or root canal procedure, depending on its depth.
Dental Abscesses and Pulp Infections
A severe, throbbing toothache may be caused by an abscess. This is a pocket of pus that forms when bacteria infect the tooth or surrounding gum tissue.
Bacteria can reach the inner pulp through an untreated cavity, crack, injury, or failed restoration. The infection may cause constant pain, sensitivity to pressure, swelling, fever, swollen glands, or a foul taste in the mouth.
The pain may spread toward the jaw, ear, or neck. In some cases, the pain suddenly becomes less intense if the pulp dies or the abscess drains, but this does not mean the infection has disappeared.
A dental abscess requires urgent treatment and will not resolve on its own. A dentist may drain the infection, perform root canal treatment, or remove a tooth that cannot be saved.
Cracked Teeth, Broken Fillings, and Dental Injuries
A cracked tooth can cause sharp pain when biting, especially when you release pressure. It may also react to cold drinks because the crack allows movement or irritation inside the tooth.
Cracks can result from biting hard foods, teeth grinding, an accident, or gradual weakening around a large filling. Some are easy to see, while others are extremely small and difficult to identify without a dental examination.
A loose, worn, or broken filling may expose sensitive dentin or allow food and bacteria to enter around the restoration.
Dental crowns can also become loose or damaged, creating discomfort underneath them. The NHS lists cracked teeth and broken fillings among the common causes of toothache.
Avoid chewing on the painful side until the tooth is assessed. Continuing to bite on a fracture may cause it to spread and make the tooth more difficult to restore.
Gum Disease and Trapped Food
Pain around a tooth does not always come from inside the tooth itself. Inflamed or infected gums can feel sore, swollen, or tender during brushing and chewing.
Gum disease begins when plaque accumulates around the gumline. In its early stage, gingivitis may cause redness and bleeding. Advanced periodontitis can damage the deeper tissues and bone supporting the teeth, leading to painful chewing, gum recession, or loose teeth.
Food trapped between two teeth may also press against the gum and cause surprisingly intense discomfort. Popcorn husks, seeds, or fibrous food are common examples.
Gently cleaning the area with floss or an interdental brush may relieve pressure. However, repeated food trapping can indicate a cavity, broken filling, gum pocket, or gap between teeth that needs professional evaluation.
Teeth Grinding and Wisdom Teeth
Bruxism is the habit of grinding or clenching the teeth, either while awake or during sleep. Severe grinding can wear enamel, crack teeth, and cause sensitivity, tooth pain, headaches, or tired jaw muscles.
Unlike pain from a single cavity, bruxism may make several teeth feel sore at once. Symptoms are often worse in the morning, and the jaw may feel tight or fatigued.
Wisdom teeth can cause pain when they begin breaking through the gums but do not have enough room to emerge correctly. Partially erupted teeth may trap food and bacteria beneath a flap of gum tissue, causing inflammation or infection.
Pain at the back of the mouth, swollen gums, an unpleasant taste, or difficulty opening the jaw should be checked by a dentist.
When Tooth Pain Comes From Somewhere Else
Occasionally, a healthy tooth can feel painful because discomfort is being referred from another part of the face.
A sinus infection is one example. The roots of the upper back teeth sit close to the maxillary sinuses, so sinus inflammation can create pressure that feels like a toothache. Several upper teeth may ache together, especially when bending forward.
Jaw-joint problems and tight chewing muscles may also create pain near the molars. Less commonly, nerve conditions such as trigeminal neuralgia can cause sudden electric-shock-like facial pain triggered by touching the face, talking, eating, or brushing.
A dentist will normally check for dental causes first. When the teeth and gums appear healthy, medical assessment may be needed to investigate sinus, nerve, ear, or jaw problems.
When Should You See a Dentist?
Arrange a dental appointment when pain lasts longer than a day or two, returns repeatedly, wakes you at night, or occurs when biting. Fever, red gums, swelling, or foul-tasting discharge can indicate infection and require prompt attention.
Seek urgent dental care if the pain is severe, an abscess is suspected, or swelling develops in the face or jaw. An abscess can spread if it is not treated.
Difficulty breathing, speaking, or swallowing requires emergency medical help. Major mouth swelling, swelling near the eye, or sudden vision changes are also emergency warning signs.
Do not wait for pain to become unbearable. Dental treatment is often simpler when the cause is identified early.
What Can You Do While Waiting for Treatment?
Temporary self-care may make you more comfortable, but it does not fix the cause of a toothache.
Rinse gently with warm salt water, then spit it out. Choose soft foods and avoid very hot, cold, sugary, or hard items that trigger pain. Continue cleaning your teeth carefully with a soft toothbrush.
Over-the-counter pain medication may help when it is safe for you, but follow the label and check with a pharmacist or healthcare professional if you have medical conditions, take other medicines, are pregnant, or are treating a child.
Non-opioid medicines are recommended as first-line options for many forms of acute dental pain.
Never place aspirin directly against a tooth or gum because it can damage the tissue. Use caution with numbing products containing benzocaine, especially in young children.
How to Lower Your Risk of Toothache
Brush twice daily for about two minutes with fluoride toothpaste. Clean between your teeth every day using floss or interdental brushes, and limit frequent sugary foods and drinks.
Wear a suitable mouthguard during contact sports, and ask a dentist about a night guard if you grind your teeth. Avoid chewing ice or using your teeth to open packaging, as these habits can cause fractures.
Regular dental examinations matter because cavities, loose restorations, gum disease, and impacted teeth may be detected before they begin causing significant pain.
Toothaches can come from cavities, pulp infections, abscesses, cracked teeth, damaged fillings, gum disease, wisdom teeth, or grinding. Some pain is also referred from the sinuses, jaw muscles, or facial nerves.
Although the location and pattern of discomfort may provide clues, only a professional examination can confirm the cause. Home remedies and pain medication may reduce symptoms temporarily, but they cannot repair decay or eliminate an infection.
Book a dental appointment when pain persists, becomes stronger, or repeatedly returns. Seek urgent help for fever, facial swelling, discharge, or difficulty opening your mouth. If breathing or swallowing becomes difficult, get emergency medical care immediately.