A tooth infection happens when bacteria enter the inside of a tooth or surrounding dental tissues, often because of untreated tooth decay, a cracked or damaged tooth, or gum disease. Early infection may cause toothache, sensitivity, pain when biting, or gum tenderness. As infection progresses, pus, swelling, fever, facial swelling, or difficulty opening the mouth may develop.

The important point for readers is that a tooth infection usually needs dental treatment to remove the source of infection. Depending on the condition of the tooth, treatment may involve drainage, a root canal, or extraction. Antibiotics may be appropriate in some situations, particularly when infection is spreading or accompanied by systemic symptoms, but antibiotics alone generally do not eliminate the underlying dental source.

1. Tooth Infection: Symptoms, Causes, Treatment & When It’s an Emergency

• What a tooth infection is
• Common causes
• Early symptoms
• Toothache
• Sensitivity to hot/cold
• Bad taste or pus
• Gum swelling
• Facial swelling
• Fever
• Swollen lymph nodes
• Tooth abscess
• How dentists diagnose it
• Root canal vs extraction
• Antibiotics: when they may and may not help
• What happens if untreated
• Emergency warning signs
• When to see a dentist
• Prevention

2. Tooth Infection Symptoms: Early Signs You Should Not Ignore

Early symptoms

• Tooth pain
• Sensitivity
• Pain when biting
• Gum tenderness
• Bad taste

More advanced symptoms

• Pus
• Gum swelling
• Facial swelling
• Fever
• Difficulty opening the mouth

3. Facial Swelling From Tooth Infection: Causes, Treatment & Emergency Signs

This deserves its own page because facial swelling is a different search intent.

• Why a tooth infection can cause facial swelling
• Gum vs cheek vs jaw swelling
• What an abscess looks like
• Why swelling can spread
• What a dentist does
• Drainage
• Root canal
• Extraction
• Antibiotics
• When swelling becomes an emergency

4. Tooth Abscess: What It Is, Symptoms & How Dentists Treat It

What is a tooth abscess?

• Periapical abscess — around the tooth root
• Periodontal abscess — involving the gum
• Gum swelling / localized infection

• Symptoms
• Causes
• Pictures/illustration
• How dangerous it can become
• Dental treatment
• Drainage
• Root canal
• Extraction
• Antibiotics
• What NOT to do at home

5. When Should You See a Dentist for a Tooth Infection?

This page answers a decision question rather than repeating symptoms.

Make a dental appointment

• Persistent tooth pain
• Sensitivity that doesn't go away
• Gum swelling
• Pain when biting

See a dentist promptly

• Pus
• Increasing swelling
• Severe toothache
• Fever

Seek emergency care

• Difficulty breathing
• Difficulty swallowing
• Rapidly increasing facial/neck swelling
• Severe weakness or systemic illness
• Difficulty opening the mouth

Tooth Infection Emergency Warning Signs

Tooth Infection Emergency: 7 Warning Signs You Should Never Ignore

1. Difficulty breathing
2. Difficulty swallowing
3. Swelling spreading toward the neck
4. Rapidly increasing facial swelling
5. Significant fever or feeling severely unwell
6. Difficulty opening the mouth
7. Swelling around the eye / vision-related symptoms