Yes, a tooth infection can cause a fever, and a fever alongside dental pain means the infection is no longer confined to the tooth. A localised abscess sitting at the tip of a root usually does not make you feel unwell all over. Once you are febrile, the infection has involved the surrounding tissue spaces or has triggered a whole body inflammatory response. That is a change of category, not a change of degree. It moves the problem from something that can wait for a convenient appointment to something that needs to be seen the same day.
Read this first
Difficulty breathing or swallowing, a swelling that is closing an eye, or feeling very unwell with a fever means an emergency department or Triple Zero (000), not a wait for a dental appointment. Do not ring a practice and wait for a call back. Do not take a leftover antibiotic and see how the night goes. Go.
Call Triple Zero (000) immediately for any of these:
- Trouble breathing, noisy breathing, or a feeling that the airway is tightening.
- Trouble swallowing, drooling because swallowing hurts, or a change in the sound of your voice.
- Firm swelling under the jaw on both sides, or a tongue that feels pushed up and back.
- Swelling closing an eye, a bulging eye, or double vision.
- Confusion, rigors or shaking chills, fast breathing, mottled or clammy skin, or not passing urine.
Go to an emergency department the same day if you cannot open your mouth more than a finger or two, if facial swelling is spreading rather than staying put, or if you have a fever with dental pain and cannot get a dental appointment. In New South Wales, public dental services direct after hours emergencies to the nearest hospital emergency department. For advice at any hour, healthdirect on 1800 022 222 has registered nurses available around the clock, and the NSW Health public dental intake line is 1800 679 336.
Key takeaways
- Fever is a recognised systemic feature of spreading odontogenic infection and is one of the findings that separates a local problem from one needing systemic antibiotics.
- Antibiotics are adjunctive. The Cochrane review published in 2024 found antibiotics for symptomatic apical periodontitis and acute apical abscess may provide negligible benefits and probably contribute to large harms.
- Therapeutic Guidelines: Oral and Dental, updated in September 2025, ties antibiotic choice in Australia to whether the definitive dental procedure will happen within 24 hours.
- Ludwig's angina, a spreading infection of the floor of the mouth usually arising from a lower molar, kills by obstructing the airway and still carries mortality around 8%.
- Trismus and difficulty swallowing occurred in over 70% of hospitalised patients in a prospective series of odontogenic infections, which makes them sentinel signs rather than minor inconveniences.
- The AIHW recorded close to 89,200 potentially preventable hospitalisations for dental conditions in a single year, and delay is a major contributor.
Why a fever changes the category
Fever tells you the infection has moved beyond the tooth. A pulp that is inflamed, or a well contained abscess at the root tip, is usually a local event. It hurts, sometimes badly, but it does not generally produce a systemic febrile response. Once fever, malaise, swollen lymph nodes or diffuse swelling appear, the picture is spreading infection, and that is precisely the distinction Australian therapeutic guidance uses to decide whether systemic antibiotics are indicated at all.
It is worth being clear about what this article will not do. It will not give you a temperature above which to go to hospital. That kind of threshold implies you are safe below it, and no trial supports a number that gives permission to wait. Fever with dental pain warrants same day professional assessment regardless of what the thermometer says.
How a dental infection escalates
Odontogenic infection follows a fairly predictable sequence, and each step has its own signs.
Local
Pain in one tooth, tenderness to biting, sometimes a small firm swelling on the gum beside the tooth. No fever, no facial swelling, no difficulty opening. The treatment is drainage, root canal treatment or extraction. This stage is uncomfortable and manageable, and it is the stage where treatment is simplest.
Spreading
Swelling of the face or jaw, a general feeling of being unwell, fever, tender lymph nodes. The infection has entered the soft tissue spaces around the jaw. This needs to be seen the same day, and antibiotics may now have a role alongside the dental procedure rather than instead of it.
Systemic and life threatening
Trismus, difficulty swallowing, drooling, voice change, swelling under the jaw on both sides, swelling around the eye, or the signs of sepsis. Flynn's severity scoring grades anatomical spaces by airway risk, from vestibular and buccal spaces at the low end, through submandibular and pterygomandibular in the middle, to lateral pharyngeal, retropharyngeal and mediastinal spaces at the high end. Once the deep spaces are involved, the question stops being about the tooth and becomes about the airway.
Ludwig's angina, trismus and the eye
Ludwig's angina is the named worst case, and most cases start with a tooth. It usually arises from a lower second or third molar and presents as firm, board like swelling of the submandibular region and floor of the mouth, with pain, difficulty swallowing, trismus, drooling, a tongue displaced upwards and backwards, a fast heart rate, fever and malaise. Before antibiotics, mortality exceeded 50%. It is now around 8%. Death comes from airway obstruction rather than from the infection itself.
Trismus and difficulty swallowing deserve their own mention. In a prospective series of 37 hospitalised patients with odontogenic infection, both occurred in over 70% of cases. If your jaw will not open more than a finger or two, that is not stiffness from clenching. It suggests the infection has reached the muscle spaces.
Eye involvement is the other pathway that gets missed. Infection can spread to cause orbital cellulitis and, through the valveless veins of the face, septic cavernous sinus thrombosis, presenting with a bulging eye, restricted eye movement and swollen conjunctiva. That is described in the literature as a medical emergency and belongs in an emergency department immediately.
Sign by sign: what it suggests and where to go
The table sets out the common presentations, in rough order of urgency.
| Sign | What it suggests | Where to go | How fast |
|---|---|---|---|
| Cold sensitivity that stops within seconds | Reversible pulpitis or exposed dentine | Dentist | Routine appointment |
| Throbbing pain, worse lying down, no swelling and no fever | Irreversible pulpitis | Dentist | Within a day or two |
| Tooth tender to bite, small localised gum swelling, no fever | Localised apical abscess | Dentist | Same day or next day |
| Facial or jaw swelling with fever or feeling unwell | Spreading infection | Dentist same day, or emergency department if none available | Same day, not tomorrow |
| Cannot open your mouth more than a finger or two | Spread into the deep muscle spaces | Emergency department | Immediately |
| Swelling under the jaw on both sides, raised tongue, drooling, voice change, trouble swallowing or breathing | Possible Ludwig's angina and an airway at risk | Triple Zero (000) | Now |
| Swelling closing an eye, bulging eye, double vision | Orbital or cavernous sinus involvement | Triple Zero (000) or emergency department | Now |
| Fever with confusion, rigors, fast breathing, mottled or clammy skin | Possible sepsis | Triple Zero (000) | Now |
Why antibiotics alone do not fix it
Antibiotics do not remove the cause. A dead pulp and a collection of pus are physical problems that need a physical solution, and the Australian and international position is that most dental infections are treated effectively by direct operative measures: drainage, removing the pulp and completing root canal treatment, or extraction. When a course of antibiotics finishes and the source is still there, the infection returns. Patients often describe this as the antibiotics not working. In fact they did what antibiotics can do, which was buy time.
The Cochrane review published in 2024 on systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults concluded that antibiotics may provide negligible benefits and probably contribute to large harms, with certainty of evidence very low to low for benefit. That is a strong statement for a Cochrane review. It applies to localised disease. Antibiotics still matter for genuinely spreading infection, and Therapeutic Guidelines: Oral and Dental, in its September 2025 update, now links the choice to timing. Penicillin alone is suggested for non-severe spreading infection where the dental procedure will happen within 24 hours, with the addition of metronidazole, or a switch to amoxicillin with clavulanate, if the procedure is likely to be delayed.
Stewardship is the reason your dentist may decline to write a script. Australian dentists dispensed almost 7 million antibiotic prescriptions over 12 years, averaging 24 prescriptions per dentist per year, and an analysis of Australian hospital prescribing for oral and dental conditions found only 44.7% were guideline compliant. Declining to prescribe when the guideline does not support it is not a dentist being unhelpful. It is the guideline working. Our article on antibiotics for a tooth infection goes through when they are and are not indicated.
What an emergency department will and will not do
An Australian emergency department manages infection, airway and pain. It does not usually treat the tooth. Staff can give intravenous antibiotics, arrange imaging, drain a collection surgically, and admit you if the airway is at risk. Definitive dental treatment still generally requires a dentist or a public dental service afterwards. Saying that plainly is not discouragement. It is so you know what to expect and do not leave frustrated that the tooth is still there.
NSW public dental services triage facial or neck swelling, mouth swelling, significant bleeding, and difficulty opening or swallowing as their most urgent category, to be seen within 24 hours. Public dental care in NSW generally requires a Medicare card and a concession card. Our guides to when to go to hospital for a dental problem and dental emergencies after hours and on public holidays cover the practical routes.
How this differs from our other infection articles
This piece is about systemic signs, meaning fever and the whole body response. Our article on facial swelling from a spreading dental infection is about the swelling itself and where in the face it travels. Tooth abscess signs and treatment covers the local problem and how it is treated. If your main question is whether to take a tablet, the antibiotics article linked above answers it directly.
Common questions
Is a fever with toothache an emergency?
Fever with dental pain needs same day assessment, and it becomes a Triple Zero (000) emergency if there is difficulty breathing or swallowing, drooling, a voice change, swelling under the jaw or closing an eye, or confusion. Do not wait to see whether it settles overnight. If you cannot reach a dentist the same day, go to an emergency department.
Will antibiotics cure a tooth abscess?
No. Antibiotics can slow a spreading infection, but the Cochrane review found negligible benefit for localised abscesses, and the tooth still needs drainage, root canal treatment or extraction. The pus and the dead pulp are physical problems. Never take a leftover course or one prescribed for somebody else.
Can a dental abscess go away on its own?
No. Pain often settles when pus drains through a small opening in the gum, and people reasonably read that as recovery. The infected pulp is still there and the process recurs, often with more swelling next time. The relief is real, but it is drainage rather than healing.
Why can I not open my mouth properly?
Trismus with a dental infection suggests spread into the muscle spaces around the jaw, and it is one of the signs that warrants urgent rather than routine care. In one prospective hospital series it appeared in over 70% of admitted patients. Treat a jaw that will not open as a reason to go to an emergency department the same day.
Can a tooth infection cause sepsis?
Rarely, but genuinely. Sepsis affects tens of thousands of Australians a year, with estimates ranging from around 55,000 cases and at least 8,700 deaths from Global Burden of Disease modelling to more than 84,000 hospitalisations in more recent hospital data. Any dental infection with fever plus confusion, rigors, fast breathing or mottled skin should be treated as a medical emergency and go straight to Triple Zero (000).
If you have dental pain with a fever and you are not in the emergency categories above, get seen the same day rather than waiting. The team at Lumi Dental in Melrose Park can assess the tooth, drain a collection where that is appropriate, and set out the options in writing before anything goes ahead. Current new patient offers are listed on current deals, you can book online, and our emergency dentist page explains how urgent appointments work.
This article is general information only and is not a diagnosis or personal advice. Dental infections vary enormously and only an in person examination can tell you how serious yours is. Please see a dental or medical professional about your own situation, and call Triple Zero (000) if you have trouble breathing or swallowing.
