Why Does My Tooth Hurt? Toothache Causes, Explained by a Dentist

Tooth pain has a way of taking over everything else. You can't chew properly, you can't sleep, and by the second day you're doing the maths on whether it might settle by itself. Most toothache causes fall into a handful of predictable categories, and the type of pain you're feeling usually points straight to which one you're dealing with.

Bradbury Dental Surgery with more than 30 years treating patients across Campbelltown and the Macarthur region. Let me walk you through what your tooth is actually trying to tell you.

What Causes a Toothache?

The most common cause of toothache is tooth decay that has reached the dentine, the softer layer sitting underneath your enamel. Enamel has no nerve supply. Dentine does. Once decay works through that outer shell, the nerve inside starts reacting to cold, heat, sugar and pressure, and you feel every bit of it.

Decay isn't the only culprit, though. These are the causes I see most often:

1. Tooth decay reaching the dentine or the pulp

2. A cracked or fractured tooth, often with nothing visible from the outside

3. A dental abscess, where infection has collected at the root tip

4. Gum disease, which leaves teeth aching and tender to touch

5. A failed, leaking or lost filling that exposes dentine again

6. Grinding or clenching, which overloads the ligament holding the tooth

7. An erupting wisdom tooth pressing against the tooth in front of it

8. Non-dental causes such as sinus pressure, ear infections and jaw joint problems

That last group catches people out constantly. Not every ache in your jaw is coming from a tooth.

One pattern I've noticed after three decades of Monday mornings: a lot of the urgent pain we see started on the Friday. People hope the weekend will sort it out. It rarely does.

If you're not sure whether decay is behind your pain, our guide to the early signs of tooth decay covers what to look for before pain even starts.

What Does Your Type of Tooth Pain Actually Mean?

The character of your pain is the single most useful clue about its cause. A sharp zing that vanishes in two seconds is a completely different problem from a deep throb that keeps you awake at 3 am.

Here's roughly how I read it in the chair:

What the pain feels like	Most likely cause	How soon to be seen
Brief zing with cold or sweet, gone in seconds	Exposed dentine, receding gums or early decay	Within a few weeks
Dull ache that comes and goes, hard to pinpoint	Early pulp irritation or gum inflammation	Within a week
Ache that lingers 30 seconds or more after hot or cold	Pulp inflammation that won't settle by itself	Within days
Sharp jab when you bite down, then relief on release	Cracked tooth or a filling sitting too high	Within days
Constant throb, worse lying flat	Pulp infection heading toward an abscess	This week, sooner with swelling
Deep root ache with swelling, fever or a bad taste	Dental abscess	Same day
Pressure across several upper teeth at once	Sinus rather than tooth	See your GP first

None of this replaces an examination. But it does tell you how fast to pick up the phone.

A dull ache that wanders and won't localise is one of the trickier ones. Teeth share nerve pathways, so early pulp trouble often feels vague for a week or two before it declares itself properly.

How Long Does a Toothache Last?

A toothache from minor irritation, like food wedged between two teeth or a new filling sitting slightly high, usually settles within 24 to 48 hours. Pain caused by decay, a crack or infection won't resolve on its own, because nothing has removed the cause. That kind can carry on for weeks, and it tends to come in waves rather than building steadily.

So, does a toothache go away by itself? Sometimes the pain does. The problem underneath almost never does.

When the pain stops, it isn't always good news

If a tooth throbs badly for several days and then goes quiet, the nerve inside may have died. The pressure driving the pain is gone, but the bacteria aren't. Infection carries on spreading through the root and into the bone, and the next symptom is often facial swelling weeks or months down the track.

I've had patients come in relieved that it fixed itself, only for an x-ray to show an abscess under a tooth that hasn't hurt since autumn. A tooth that hurts a lot and then suddenly stops needs checking, not celebrating. We go through what that looks like in our guide to treating a dental abscess.

Why Do My Upper Teeth Hurt? Sinus Pain vs Tooth Pain

If several upper back teeth ache at once, sinus pressure is more likely than a dental problem. Your maxillary sinuses sit directly above the roots of your upper molars and premolars, in some people separated by less than a millimetre of bone. When those sinuses fill up, that pressure bears down on the nerves feeding the teeth below.

Three quick checks:

• How many teeth hurt? Sinus pain affects several upper teeth together. Dental pain usually points to one.

• Does bending forward make it worse? Sinus pain does. A sore tooth generally doesn't care what your head is doing.

• Have you been unwell? A recent cold, hay fever or blocked nose makes sinus involvement far more likely.

Sinuses almost never cause pain in your lower teeth. If your bottom teeth are the sore ones, look for a dental cause.

Every winter our Bradbury clinic sees a run of patients certain they've got a bad tooth up the back, when what they've really got is sinusitis. A GP visit sorts that out faster than we can.

Can a Toothache Cause Headache or Ear Pain?

Yes, and it runs in both directions. The trigeminal nerve supplies your teeth, jaw, ear region and much of your face, and the brain isn't always precise about where a pain signal started. That's referred pain, and it's very common.

An infected lower molar often feels like earache. An upper molar can throw a headache across your temple. Jaw joint trouble can mimic all of the above, which is why we treat jaw pain and its common causes as its own topic.

The giveaway is usually temperature. If a hot cup of tea or a cold drink sets it off, the source is almost certainly a tooth.

What Actually Helps a Toothache at Home?

You can control tooth pain at home. You can't heal the tooth at home. Keeping those two apart saves people a lot of wasted effort, and a fair bit of damage.

Over-the-counter pain relief, taken properly, is the most effective thing you can do while you wait for an appointment. In Australia that means paracetamol (Panadol and generic brands) or ibuprofen (Nurofen and generic brands), taken exactly as directed on the packet.

Research on acute dental pain consistently shows that paracetamol and ibuprofen taken together give better relief than either one on its own, because they work through different pathways. A lot of people don't realise the two can be combined at all. Check with your pharmacist before you do, particularly if you have asthma, stomach ulcers, kidney problems, or you're pregnant or on blood thinners.

Alongside that:

• Rinse gently with warm salty water

• Hold a cold pack against the outside of your cheek, never directly on the gum

• Prop your head up on an extra pillow at night

• Stick to soft food and chew on the other side

Night-time is its own particular misery, and there's more you can do about it than most people think. We've covered that in our post on easing tooth pain at night.

What to avoid

Do not hold a soluble aspirin tablet against the sore gum. I've treated the chemical burns that come from this more times than I'd like, and they leave a white, sloughy ulcer that ends up hurting more than the tooth did.

Skip heat on a swollen face, since warmth encourages infection to spread. Clove oil takes the edge off briefly, but used repeatedly it irritates the gum, and it does nothing at all to the problem underneath.

About "killing the nerve" at home

You'll find plenty of content online promising to stop tooth nerve pain in seconds. There's no home method that reaches the nerve inside a tooth. It sits in a sealed chamber under several millimetres of enamel and dentine, and nothing you rinse, rub or press against the outside gets anywhere near it. Anything that did reach it would be causing real damage on the way in.

Pain relief buys you time to get seen. That's what it's for, and that's fine.

When Should You See a Dentist About Tooth Pain?

Book an appointment if tooth pain lasts more than 48 hours, wakes you at night, or keeps returning over several weeks. Those three signals nearly always mean something structural has changed inside the tooth.

Get seen the same day if you notice any of these:

• Swelling of your face, cheek, jaw or neck

• Fever, or feeling unwell alongside the pain

• A bad taste or discharge near the sore tooth

• Trouble opening your mouth or swallowing

• Pain that started after a knock or injury

Difficulty swallowing or breathing alongside facial swelling is a medical emergency rather than a dental one. Go straight to a hospital emergency department or call 000.

The 48-hour rule, and why it exists

Two days is roughly how long it takes to tell the difference between irritation and damage. Irritation settles. Damage doesn't, and by day three you're usually dealing with something that has moved deeper into the tooth than it was on day one.

Where Do You Actually Go With a Toothache in Campbelltown?

This is the part almost nobody writes about, and it's the question I get asked most often when the pain starts on a Saturday.

If you hold a concession card, you may be eligible for public dental care through South Western Sydney Local Health District. The Dental Centre at Campbelltown Hospital is a 20-chair public clinic that opened in 2022, and it covers residents of Campbelltown, Camden, Wollondilly, Wingecarribee, Liverpool, Fairfield and Bankstown. Before it existed, people from around here were referred out of the district entirely.

Eligibility for adults means a valid Health Care Card, Pensioner Concession Card or Commonwealth Seniors Health Card. A State Seniors Card on its own doesn't qualify you. The intake line is 1800 679 336, Monday to Friday, roughly 8am to 4pm.

Two things to know before you ring:

• Emergency cases are prioritised, but toothache on its own isn't classified as an emergency. Swelling, uncontrolled bleeding, trauma and difficulty swallowing are.

• Public dental can issue an OHFFSS voucher that lets you be treated at a registered private practice instead. We accept these, and plenty of patients don't realise the option exists.

For children under 18, the Child Dental Benefits Schedule covers a set amount of dental treatment over two calendar years for eligible families. It's underused locally, and it covers exactly the kind of decay that causes a child's first toothache.

After hours, Campbelltown Hospital's emergency department is the fallback for facial swelling, bleeding that won't stop, or trauma. NSW clinical guidance through the Emergency Care Institute is clear that routine dental care belongs in the community rather than the hospital. An ED will manage your pain and treat spreading infection. They won't fix the tooth.

Everyone else goes private. At Bradbury Dental Surgery, we hold time aside each day for urgent dental appointments in Campbelltown, including for patients travelling in from Camden, Narellan and the surrounding Macarthur suburbs.

What Treatment Will You Need?

Treatment depends entirely on the cause. Decay caught early is usually a matter of cleaning it out and placing a tooth-coloured filling. Once decay or a crack reaches the pulp, root canal treatment is generally how the tooth gets saved, and most patients are surprised how manageable it is compared to what they'd imagined. Where the pain is coming from inflamed gums, gum disease treatment settles things down.

Some sensitivity after a filling or root canal is normal for a few days, and we've explained what's normal after root canal treatment separately.

The timing matters more than most people expect. A small filling today is a very different appointment, and a very different cost, from a root canal in three months.

Frequently Asked Questions

Can a toothache go away on its own? 

The pain can, but the cause usually doesn't. Pain from trapped food or minor gum irritation often settles within a day or two. Pain from decay, a crack or infection may fade if the nerve dies, while the infection continues underneath.

How long is too long to leave a toothache? 

Anything past 48 hours warrants an appointment. Pain that wakes you at night, or that keeps coming back over weeks, needs looking at even if it's mild between episodes.

Can I go to hospital for a toothache? 

You can, and NSW hospital emergency departments will manage pain and treat spreading infection. They don't generally provide dental treatment, so you'll still need to see a dentist afterwards to deal with the tooth itself.

Why does my toothache feel worse at night? 

Lying flat increases blood flow to your head, which raises pressure inside an already inflamed tooth. There are also fewer distractions after dark, so you notice it more.

Does a toothache always mean I have a cavity? 

No. Cracked teeth, gum disease, grinding, sinus pressure and erupting wisdom teeth all cause tooth pain without a cavity being present. Sensitivity to hot and cold often comes from worn enamel or receding gums instead.

Toothache Causes Don't Fix Themselves

Nearly every toothache cause is more comfortable, quicker, and cheaper to treat early. The ones that turn into difficult appointments are almost always the ones that waited.

If a tooth has been bothering you for more than a couple of days, come and let us have a look. We see tooth pain every single day at Bradbury Dental Surgery, and we can usually tell you what's going on in one visit. Call us on (02) 4628 2151 or book online, and if you're overdue anyway, a routine dental check-up is often where these problems get caught before they ever start hurting.