Can a Tooth Infection Cause Headaches?

Several mechanisms connect dental infections to head pain:

The trigeminal nerve connection
The trigeminal nerve is the fifth cranial nerve and is responsible for sensation throughout your face. It has three major branches: one supplies the forehead and upper face, one supplies the cheek area and upper teeth, and one supplies the lower jaw and lower teeth.

Because all three branches ultimately connect to the same nerve trunk, irritation in one branch can cause pain in areas supplied by other branches. This phenomenon is called "referred pain." An infected lower molar can cause pain in your temple, and an infected upper tooth can cause pain around your eye—even though nothing is wrong with those areas directly.

Sinus involvement
The roots of your upper back teeth sit very close to your maxillary sinuses—in some people, they actually protrude into the sinus cavity. When an upper tooth becomes infected, the infection can spread into the sinus or cause inflammation that mimics sinus problems.

This creates the classic "sinus headache" pattern: pressure and pain around the cheeks, between the eyes, and across the forehead. Many people treat these symptoms as a sinus infection or allergies, never realizing the true source is dental.

Muscle tension from chronic pain
Tooth pain is exhausting. You unconsciously clench your jaw, tense your facial muscles, and hold your head in unusual positions trying to minimize discomfort. Over hours and days, this muscle tension creates secondary tension headaches—a tight, band-like pain around your head, particularly in the temples and back of the skull.

Systemic inflammatory response
When your body fights an infection, it releases inflammatory chemicals called cytokines. These chemicals don't stay localized to the infection site—they circulate throughout your body and can trigger headache symptoms, fatigue, and general malaise. This is why you might feel like you have the flu when you have a significant tooth infection.

Sleep disruption
Tooth infections often cause pain that worsens at night (because lying down increases blood flow to the head). Poor sleep leads to headaches. If you've been waking up with headaches alongside tooth pain, the connection is likely sleep deprivation from nighttime dental pain.

Different mechanisms produce different headache patterns:

Referred pain headaches
These feel like the headache is coming directly from your head, not your tooth. The pain may be focused around your eye, temple, forehead, or ear—depending on which tooth is infected and your individual nerve anatomy. The clue that it's referred pain: pressing on the infected tooth or tapping it makes the "headache" worse.

Sinus-type headaches
Caused primarily by upper tooth infections affecting the sinuses. Symptoms include:

• Pressure and pain in the cheek area


• Forehead pain or pressure


• Pain that worsens when bending forward


• Feeling of "fullness" in the face


• Sometimes nasal congestion (or feeling like there should be congestion even when the nose is clear)

Tension-type headaches
The secondary headache from muscle clenching and poor sleep. Characteristics include:

• Band-like pressure around the head


• Pain in temples and back of head/neck


• Muscle tenderness in jaw, neck, and shoulders


• Headache that develops over the day or after periods of stress

Migraine-type headaches
In people who are prone to migraines, tooth infections can act as triggers. The inflammation and pain can set off a migraine episode with all the classic features: intense one-sided pain, sensitivity to light and sound, nausea, and sometimes visual disturbances. If you get migraines and notice they're more frequent or severe during periods of dental problems, there's likely a connection.

Whole-head achiness
The systemic inflammatory response can cause a general, all-over headache similar to what you feel when you have the flu. This type typically accompanies other signs of infection like fever and fatigue.

It can be challenging to connect head pain to a dental source, especially if your tooth pain is mild or intermittent. Here are signs that suggest a dental origin:

Signs pointing to a dental cause:

• Headache started around the same time as tooth pain or sensitivity


• Tapping on a specific tooth triggers or worsens the headache


• Chewing or eating aggravates the head pain


• You have visible tooth decay, a broken tooth, or swollen gums


• The headache doesn't respond well to typical headache treatments


• You have a history of dental problems in the area


• Pain is more on one side, corresponding to a problem tooth


• Headache accompanies other infection signs (swelling, fever, bad taste)

Signs that suggest a non-dental cause:

• Headache pattern matches your typical migraines or tension headaches


• No tooth symptoms whatsoever


• Headache responds normally to your usual treatments


• Clear triggers unrelated to eating or dental function (stress, lack of sleep, certain foods)


• No dental problems visible or known

When you're not sure:
See both your dentist and your doctor. Sometimes headaches and dental problems coexist without being related, and you need treatment for both. Other times, what seems like two separate problems is actually one issue manifesting in different ways.

The good news about dental-related headaches: treating the tooth infection almost always resolves the headaches.

What treating the infection involves:

For mild infections:
Your dentist may prescribe antibiotics to control the bacterial infection while scheduling definitive treatment. Antibiotics alone won't cure the infection permanently, but they can reduce inflammation and headache-causing symptoms while you wait for your procedure.

Root canal therapy:
If the tooth can be saved, a root canal removes the infected pulp tissue, eliminating the source of infection. Once the nerve is removed and the canals are sealed, the inflammatory process stops and referred pain (including headaches) typically resolves within days.

Tooth extraction:
If the tooth cannot be saved, extraction removes both the tooth and the infection. Healing takes a bit longer than after a root canal, but headaches related to the infection should resolve as the area heals.

Timeline for headache relief:

• Antibiotics: Headaches often improve within 24-48 hours as infection/inflammation decreases


• After root canal: Most patients notice significant headache improvement within 2-3 days


• After extraction: Headaches typically resolve as the extraction site heals, usually within 1-2 weeks

Pain management while waiting for treatment:

• Alternate ibuprofen and acetaminophen for both tooth and headache pain


• Apply ice pack to the jaw (20 minutes on, 20 minutes off)


• Sleep with head elevated to reduce nighttime throbbing


• Avoid chewing on the affected side


• Gentle salt water rinses can soothe inflammation

While most dental-related headaches are uncomfortable but not dangerous, certain combinations of symptoms require immediate medical attention:

Seek emergency care if you have:

• Severe headache with high fever (over 101°F)


• Stiff neck combined with headache and fever (signs of meningitis)


• Confusion, disorientation, or altered consciousness


• Visual changes with headache


• Facial swelling spreading toward the eye or down the neck


• Difficulty breathing or swallowing


• Rapidly worsening symptoms

These can indicate that infection has spread beyond the tooth into more dangerous areas. Dental infections can, in rare cases, spread to the brain, causing brain abscesses or meningitis. They can also spread into the fascial spaces of the neck, compromising the airway. These are medical emergencies.

The bottom line:
A dull headache with an achy tooth warrants a dental appointment. A severe headache with fever, swelling, and signs of spreading infection warrants an emergency room visit.