Pain & Emergencies

Why does my tooth hurt?

A toothache is a symptom, not a diagnosis. The pattern of the pain usually tells us which tissue is involved: a short sharp reaction to cold suggests exposed dentine or a failing filling, a deep throbbing ache that lingers or wakes you suggests the pulp is inflamed or infected, and pain on biting a single tooth suggests a crack or infection at the root tip. The tooth cannot be diagnosed by its pain alone — an examination with a radiograph is what separates these.

What toothache usually turns out to be

  • Dental decay reaching the dentine or the pulp
  • Pulpitis — reversible or irreversible inflammation of the tooth's nerve
  • An abscess at the root tip or in the gum
  • A cracked tooth or a fractured cusp
  • A failed or leaking filling or crown
  • Gum recession and exposed root surfaces
  • Pericoronitis around a partly erupted wisdom tooth
  • Referred pain from the sinus or the jaw joint

What to do before you are seen

  • Keep the area clean; rinse with warm salt water rather than probing the tooth
  • Take the painkiller you normally tolerate, at its labelled dose
  • Avoid very hot, very cold and very sweet foods on that side
  • Do not place aspirin or clove oil directly on the gum — it burns the tissue
  • Book an examination — pain that returns is a diagnosis waiting to be made

This is general guidance and does not replace an examination. Only a clinical examination with radiographs can identify which tooth or tissue is causing your symptom.

When to see us

  • Facial or neck swelling, difficulty swallowing, opening the mouth or breathing — this is an emergency
  • Pain with fever, or swelling that is spreading rather than settling
  • A tooth knocked out or pushed out of position after an injury — time matters
  • Pain that wakes you at night or does not respond to ordinary painkillers

Detailed guides on this symptom

Untreated Cavity Spreading to the Dental Pulp Nerve

When dental decay reaches the tooth pulp, bacterial infection inflames the internal nerve and blood vessels. Left untreated, irreversible pulpitis progresses to necrosis and spreading facial abscesses. Prompt root canal treatment or extraction is required to eliminate infection.

11 min read

Tooth Sensitivity to Heat That Lingers After Drinking

Lingering tooth pain from hot food or drinks typically indicates irreversible pulpitis, an advanced inflammation of the dental pulp. This clinical guide explains pulpal anatomy, diagnostic procedures, treatment pathways including root canal therapy, and critical red flag symptoms requiring emergency dental care.

11 min read

What to Do When a Dental Crown Falls Off

A dislodged dental crown requires prompt clinical assessment to prevent underlying tooth decay, pulpitis, and structural damage. Learn how to safely manage the crown at home, diagnostic pathways, recementation procedures, and critical red flags requiring urgent dental care.

11 min read

Why Tooth Pain Gets Worse When Lying Down

Experiencing toothache worse lying down typically indicates elevated pulpal or periapical pressure driven by increased cranial blood flow when supine. This guide explains pulpal anatomy, underlying causes, diagnostic pathways, evidence-based treatments, and critical red flags requiring emergency care.

10 min read

Throbbing Tooth Pain When Lying Down Causes

Experiencing a tooth throbbing when lying down typically indicates pulpitis or periapical inflammation. Positional changes increase cranial blood pressure within the confined tooth chamber. Accurate diagnosis, prompt root canal treatment, or dental extraction resolves the underlying pathology and prevents severe complications.

10 min read

Signs of Tooth Decay Under an Existing Crown

Decay under an existing dental crown occurs when bacteria breach the cement margin to attack underlying natural tooth structure. Recognising early symptoms like marginal discolouration, persistent odour, sensitivity, or bite pain enables timely intervention before deep pulpal infection develops.

11 min read

Why a Tooth Hurts Under an Old Dental Filling

Pain under an old tooth filling usually indicates recurrent decay, marginal breakdown, cracked tooth structure, or progressive pulpal inflammation. Understanding the underlying clinical cause helps determine whether replacement, indirect coverage, or root canal therapy is necessary.

11 min read

How to Tell a Sinus Infection from a Toothache

Distinguishing a sinus toothache from a dental cavity requires understanding maxillary anatomy, pain characteristics, and clinical tests. This guide details diagnostic differences, causes of odontogenic versus rhinogenic sinusitis, examination steps, evidence-based treatments, and critical red flags.

11 min read

Toothache While Flying or Scuba Diving Explained

Barodontalgia is severe tooth pain triggered by barometric pressure changes during flying or scuba diving. It stems from underlying dental pathology, requiring clinical examination, precise diagnostic imaging, and definitive dental treatment to prevent complications like restoration fracture.

11 min read

Extreme Tooth Sensitivity to Hot and Cold Liquids

Severe tooth sensitivity to hot and cold indicates compromised enamel, exposed dentine, or pulpal inflammation. This clinical guide outlines underlying biological causes, diagnostic pathways, classification from hypersensitivity to irreversible pulpitis, evidence-based treatments, and red flags requiring urgent intervention.

11 min read

Atypical Odontalgia and Phantom Tooth Pain Causes

Phantom tooth pain, clinically termed atypical odontalgia or persistent idiopathic dentoalveolar pain, is a chronic neuropathic condition causing persistent toothache without dental pathology. Learn about its biological causes, diagnostic pathways, differential diagnosis, and evidence-based non-surgical management.

11 min read

Severe Toothache: Common Causes and What They Mean

A guide to understanding the different causes of severe toothache, from decay and infection to gum disease and sinus issues, to help you know when urgent care is needed.

7 min read