Toothache: causes, what to do, and when is it an emergency?

Pain that wakes you up at night, a tooth that hurts with cold, or a swollen cheek: toothache is one of the most common reasons for an urgent visit to the dentist. This guide helps you understand what your pain may mean, what you can do while you wait for your appointment, and when you must go to the emergency department straight away. It is for information only and does not replace an examination: only a dentist can find the cause.

First: when should you go to the emergency department straight away?

Go to the emergency department straight away if you have:

difficulty breathing or swallowing;
swelling that spreads quickly towards the eye, the neck or under the jaw;
fever with facial swelling and severe tiredness;
a whole tooth knocked out by an injury (especially in a child or teenager): every minute counts.

If you have severe pain without these signs, call your dentist as soon as possible.

What does your pain mean?

The type of pain gives a first idea of the cause, but it is not enough to make a diagnosis.

What you feel	What it may mean
Short, sharp pain with cold or sweet things, which goes away quickly	Sensitive teeth, or early tooth decay
Pain that lasts after cold or heat, wakes you up at night, or comes for no reason	Inflamed tooth nerve (the soft inner part of the tooth)
Pain when biting, a tooth that feels "longer", swelling of the gum or cheek	An abscess or infection at the tip of the root
Pain at the back of the mouth with swollen gums and difficulty opening your mouth	Inflammation around a wisdom tooth
Pain in several upper teeth, worse when you bend forward, with a cold	It may come from the sinus, not the teeth
Pain in the jaw or temple in the morning, with tired muscles	Clenching or grinding your teeth, or a jaw joint problem

Sensitive teeth

Sensitive teeth cause a short, sharp pain when an exposed part of the tooth meets cold, sweet things or touch. It is common: depending on the study, it affects between 8.6 and 84.7 percent of people, and it is more frequent with tooth wear, acidic foods, and habits such as clenching your teeth (Denucci et al., 2026, PubMed). It can also be caused by receding gums.

Inflamed tooth nerve

When deep decay or a crack reaches the heart of the tooth, the nerve becomes inflamed: the pain becomes strong and lasting, and it often gets worse at night or when you lie down. A Cochrane review points out that this irreversible inflammation is one of the most common reasons for an urgent dental visit, and that the pain is usually relieved by root canal treatment or by removing the tooth (Agnihotry et al., 2019, PubMed).

Abscess

When the tooth nerve dies, an infection can form at the tip of the root, then an abscess: pain when biting, swelling, pus, and sometimes fever. An abscess does not go away on its own, even if the pain calms down: the cause must be treated.

What to do while you wait for your appointment

Book an appointment quickly, and describe your pain precisely: since when, what triggers it, whether it wakes you up at night, whether there is swelling.
Brush gently around the painful tooth, and use floss to remove any trapped food.
Avoid very cold, very hot and sweet things, and chew on the other side.
If there is swelling, you can put something cold on your cheek, on the outside, for short periods.
Ask a pharmacist or doctor for a painkiller suited to your situation, your age and your medicines, and stick to the dose. Tell them if you are pregnant or breastfeeding, or if you have kidney or stomach problems or a drug allergy.

What to avoid

Do not put a tablet on the gum or the tooth to ease the pain: it can burn the gum and does not treat the cause.
Do not put heat on a swollen cheek.
Do not take an antibiotic without an examination: for an inflamed nerve, there is not enough evidence to say that antibiotics relieve the pain (Agnihotry et al., 2019, PubMed); and a review by the American Dental Association points out that their benefit in these cases is uncertain, while their harms can be significant (Tampi et al., 2019, PubMed). Antibiotics are decided by the doctor in specific cases, such as a spreading infection or fever.
Do not put it off if the pain suddenly calms down: this may mean the nerve has died, and the infection can carry on silently.

How does the dentist treat toothache?

The dentist starts with an examination, often with an X-ray, then treats the cause:

Sensitive teeth: a special toothpaste, or a protective coating, and dealing with the cause (brushing too hard, acidic foods, clenching).
Tooth decay: removing the decayed part and placing a filling.
Inflamed nerve or abscess: root canal treatment (cleaning and filling the root canals) to save the tooth, or removing it if it cannot be saved; if there is an abscess, it may need to be drained.
Wisdom tooth: cleaning under the gum, then discussing removal if the episodes keep coming back (see the wisdom teeth guide).
Clenching: a night guard, depending on the case.

Toothache in children

A child may find it hard to describe their pain: they may refuse to eat, chew on one side only, or cry at night. A decayed baby tooth hurts and gets infected just like an adult tooth, and it must be treated: it keeps the space for the adult tooth that will come after it. Do not give your child any medicine without the advice of a doctor or pharmacist, and at a dose suited to their age and weight.

Toothache during pregnancy

Pregnancy is not a reason to put off treating a painful tooth: tell your dentist you are pregnant, and they will choose the right treatment and timing with you, in agreement with your doctor if needed. Do not take any painkiller without advice.

How to protect your teeth from pain

Brush your teeth twice a day with a fluoride toothpaste, and clean between your teeth every day.
Cut down on sugary snacks between meals and on acidic drinks.
See your dentist regularly: a small cavity is easy to treat before it reaches the nerve.
If you clench your teeth, talk to your dentist.

Frequently asked questions

How can I ease toothache at night?

Clean the area gently, avoid cold and hot things, raise your head a little on the pillow, and ask a pharmacist for a painkiller suited to your situation; pain that wakes you up at night needs an appointment soon, because it may be a sign of an inflamed nerve.

Can toothache go away on its own?

It may calm down, but the cause usually remains: tooth decay does not heal by itself, and a dead nerve can cause an abscess later; that is why you need an examination even if the pain has eased.

Do antibiotics treat toothache?

Not in most cases: the pain comes from a cause that must be treated in the tooth itself; antibiotics are kept for specific cases decided by the doctor, such as a spreading infection with fever.

When is toothache an emergency?

If you have difficulty breathing or swallowing, swelling that spreads quickly, or fever with swelling: go to the emergency department straight away; if you have severe pain without these signs, call your dentist as soon as possible.

Why do my teeth hurt with cold?

Usually because of sensitive teeth, when part of the tooth is exposed by wear or receding gums, or because of early tooth decay; but if the pain lasts a long time after the cold, it may be a sign of an inflamed nerve and needs an examination.