Why does my bad tooth give me a migraine on one side?

What if the migraine on one side of your head is linked to a bad tooth? It is possible. The trigeminal nerve carries sensation from your teeth, jaw and face, so a bad tooth, whether infected, cracked or severely decayed, can send pain to your jaw, cheek, temple or ear on the same side, and the result can be mistaken for a migraine.¹^,² A dental provider can help sort out whether the tooth is part of the picture. 

What you'll learn in this article: 

• The trigeminal nerve serves one side of the face, which helps explain why tooth-related headaches usually show up on the same side. 

• A dental infection is one possible trigger, and the aching may worsen without treatment.

• If the aching is consistently on the same side as a tooth you already know is problematic, the tooth may be contributing to the symptoms.

• Swelling, fever or difficulty swallowing alongside the headache signals an infection that needs same-day evaluation.

• Treating a dental problem that is contributing to head pain may help, though results and timing vary and relief is not guaranteed. 

If these symptoms sound familiar, schedule an appointment with your nearest Aspen Dental provider. 

How a bad tooth sends aching to one side of your head 

Your teeth and much of your head share one nerve network, which helps explain how a problem in your mouth can be felt in your temple or ear.¹ 

Why does the discomfort only happen on one side? 

The trigeminal nerve, which carries sensation from the teeth and face, has separate branches for each side of the mouth. When a tooth becomes infected, damaged or irritated, the discomfort usually travels along the nerve pathways on that same side. That's why a problem with a tooth on the left side is more likely to cause aching in the left jaw, cheek, temple or ear rather than the right side.¹ 

This discomfort often feels very localized because the nerve signals typically do not cross to the opposite side of the face. 

What is referred pain? 

This aching felt somewhere other than the actual source is called referred pain. Your brain struggles to pinpoint exactly where a nerve signal started, so it registers the discomfort across a wider area. A bad tooth produces head and face aching in the same way a heart attack can produce arm aching; the tooth is the source, but the head is where you feel it. This connection isn’t always clearly explained, which can leave patients wondering why a tooth problem seems to be causing a migraine.¹ 

Can a bad tooth actually trigger a real migraine? 

Possibly. Your teeth, jaw and much of the face share nerve pathways through the trigeminal nerve, which also plays a central role in migraine disorders. When a tooth is infected, damaged or severely inflamed, persistent irritation can sensitize the trigeminal nerve, and one case report describes dental problems prolonging a patient’s chronic migraine.¹^,² 

As a result, some people may notice throbbing, one-sided head pain or nausea that can feel like a migraine. A medical review describes the trigeminal nerve as the common pathway in many headache and facial pain conditions, and notes that some persistent facial pain can be secondary to dental or oral conditions.¹ 

Which dental problems can cause this 

Now that you know how the signal travels, here is what starts it. Not every tooth problem generates enough nerve irritation to reach your head, but these do. 

Tooth infection or abscess 

A bacterial infection inside a tooth can cause inflammation that irritates the trigeminal nerve, producing throbbing discomfort that radiates into the jaw, face, temple or one side of the head. Because these symptoms can closely resemble a migraine, dental infections can be overlooked as a possible cause of one-sided head discomfort.  

One case report described a man with chronic migraine headaches for 35 years whose headaches stopped after two abscessed teeth were removed and his other dental problems were treated, and they had not returned 24 months later. The authors concluded that his dental problems had been prolonging the headaches. A single case cannot show how often this happens.² 

A cracked tooth 

A crack exposes the nerve inside the tooth. Biting down can send sharp, electric-like sensations up the nerve pathway. Over time, this becomes a persistent, one-sided throbbing. 

Severe decay 

When decay reaches the inner pulp (the soft tissue at the center of the tooth), the nerve becomes irritated. The result is often a deep ache that radiates upward into the jaw and temple. 

Teeth grinding (bruxism) 

Constant grinding puts sustained pressure on the jaw joint and surrounding muscles. This tension produces a dull ache in the temples and behind the eyes, usually on the dominant chewing side. 

Impacted or emerging wisdom tooth

A wisdom tooth, especially in the upper jaw, sits close to major nerves and sinus cavities. As it pushes against neighboring teeth and bone, it generates pressure that radiates upward into the temple and ear on that side. If your wisdom teeth have not been evaluated and you have ongoing one-sided head aching, this is worth investigating. 

Bite compensation 

When a tooth is sore, most people instinctively shift how they chew to avoid it, often without realizing. Over time, this uneven biting pattern strains the jaw joint and surrounding muscles. That sustained tension produces a dull, one-sided ache in the temple that closely mimics a tension headache or migraine.

How to tell if your headache is coming from your tooth 

The location and pattern of aching are your clearest clues. Headaches with a dental source tend to: 

• Occur on the same side as a tooth that has been sensitive, sore or recently troublesome 

• Worsen when biting down or chewing on that side 

• Come with jaw soreness, facial tenderness or visible swelling near the tooth 

• Be accompanied by sensitivity to hot, cold or pressure in a specific tooth 

A true migraine, by contrast, typically brings light and sound sensitivity, nausea and visual changes, and may shift sides between episodes. If your headache is consistently on the same side as a tooth you already know is bad, a dental cause may warrant evaluation. 

When to seek care — and where to go 

Not every tooth-related headache is the same level of urgency. Here is how to decide what to do next. 

If you have any of these symptoms, go to an urgent care center or emergency room right away. Do not wait for a dental appointment: 

• Swelling in your jaw, cheek or neck 

• Difficulty swallowing or opening your mouth fully 

• Fever alongside the facial aching 

• Swelling spreading toward your eye or throat 

These are signs that a dental infection may have spread beyond the tooth into the surrounding tissue. That is a medical emergency. 

If your symptoms do not include any of the above, but a tooth that has been sore, sensitive or visibly damaged is now producing one-sided head aching, the two may be connected. Evaluating and treating the underlying dental issue may help address both.

A dental provider can examine the tooth, identify whether infection, a crack or decay is driving the aching and recommend the right course of treatment. Because dental infections can worsen without treatment, prompt evaluation by a dental professional is recommended. 

Schedule an appointment with your nearest dental provider to have the tooth evaluated.

Why does my bad tooth give me a migraine on one side? FAQs 

Can a tooth infection spread and make a headache worse over time? 

Yes. As a dental infection grows, it creates more pressure and more widespread nerve irritation. One-sided head aching associated with a dental abscess may worsen as the infection progresses. In rare but serious cases, an untreated dental infection can spread into the jaw and neck tissue. This is why escalating aching alongside swelling or fever requires urgent same-day evaluation, not a wait-and-see approach. 

How long does a tooth-related headache typically last? 

It depends on the cause, and there is no set timeline. In the case report described above, a man’s headaches became more frequent and severe as his dental problems progressed, and they stopped only after the infected teeth were removed and his other dental problems were treated.² Headaches from teeth grinding may ease temporarily with stress reduction but return without a long-term management plan such as a night guard.

Can this type of headache be confused with a sinus headache? 

Yes, and it often is. A bad upper tooth sits directly below the sinus cavity, which means an infected upper molar can produce pressure, facial tenderness and one-sided aching that feels identical to a sinus headache. If you have been treating a sinus headache with decongestants and it is not clearing, a tooth is worth investigating. Your dental provider can help determine whether a dental issue or a sinus issue is driving the discomfort. 

Will the headache go away once the tooth is treated? 

It might, but it isn’t guaranteed. In one case report, a man’s headaches stopped after two abscessed teeth were removed and his other dental problems were treated, and they had not returned 24 months later. One case cannot show how often this happens, and headaches have many possible causes.² If head pain continues after the tooth has been treated, let your dental provider know so they can help determine whether a separate cause needs to be addressed. 

Sources 

¹ National Institutes of Health, The Journal of Headache and Pain: “The fifth cranial nerve in headaches.” https://pmc.ncbi.nlm.nih.gov/articles/PMC7275328/ 
² National Institutes of Health, BMJ Case Reports: “Chronic migraine headache and multiple dental pathologies causing cranial pain for 35 years: the neurodental nexus.” https://pmc.ncbi.nlm.nih.gov/articles/PMC6768330/