Most sore throats are caused by viral infections and resolve on their own within a few days. Viruses account for the overwhelming majority of cases, with bacteria like group A streptococcus responsible for a much smaller share. But the real question behind “why does my throat hurt” usually isn’t academic. You want to know whether the pain you’re feeling right now needs a doctor, antibiotics, or just time and ibuprofen. The answer depends on a handful of details that are worth understanding.
Viral Infections Are the Most Common Cause by Far
The common cold, influenza, COVID-19, mononucleosis, adenovirus, and dozens of other respiratory viruses all cause sore throats. They inflame the tissues lining your pharynx, which is the medical term for the back of your throat. These infections typically come packaged with other symptoms you recognize: runny nose, sneezing, cough, mild body aches, sometimes a low-grade fever. A sore throat from a virus tends to build gradually, peaks over a day or two, and fades within about a week. Antibiotics do nothing for viral sore throats. This point gets repeated constantly in medical settings because the pressure patients put on doctors to prescribe antibiotics for viral illness remains a persistent public health problem.
When Bacteria Are the Culprit
Strep throat is the bacterial sore throat most people have heard of. It’s caused by group A streptococcus, a bacterium that infects the throat and tonsils, producing sore throat, difficulty swallowing, fever, and swollen lymph nodes.1Strep Throat. Strep Throat: Public Education Strep tends to arrive more abruptly than a viral sore throat. You might go from feeling fine to significant throat pain within hours, often with a fever above 101°F but without the cough and runny nose that accompany a cold. The absence of those cold symptoms is one of the clues doctors use to differentiate strep from a virus.
Strep isn’t the only bacterium that can infect your throat, though. Fusobacterium necrophorum, a less well-known organism, has been found at a prevalence comparable to group A strep in adolescents and young adults with pharyngitis.2PubMed Central. Prevalence of Fusobacterium necrophorum in Children Presenting with Pharyngitis This bacterium matters because it is the primary cause of Lemierre’s syndrome, a rare but dangerous condition where infection spreads to the internal jugular vein and can seed abscesses in the lungs. While Lemierre’s syndrome is uncommon, Fusobacterium appears to cause a wider spectrum of clinical disease than originally thought, from persistent local throat infections to acute systemic illness.3PubMed. Fusobacterium necrophorum as the cause of recurrent sore throat: comparison of isolates from persistent sore throat syndrome and Lemierre’s disease Standard rapid strep tests won’t detect it, and routine throat cultures typically don’t look for it, which means it can go unrecognized.
Sore Throats Without an Infection
Not every sore throat involves a germ. Acid reflux that reaches the upper throat, known as laryngopharyngeal reflux, is a surprisingly common cause of chronic or recurring throat discomfort. Unlike typical heartburn, this type of reflux often produces no burning sensation in the chest at all. Instead, symptoms include hoarseness, a persistent cough, a feeling of something stuck in the throat, excess throat mucus, and a sore throat that seems to come and go without explanation.4PubMed Central. Laryngopharyngeal reflux disease: Updated examination of mechanisms, pathophysiology, treatment, and association with gastroesophageal reflux disease Because it doesn’t feel like classic reflux, people often chase other explanations, cycling through allergy treatments and antibiotics before the real cause is identified.
Postnasal drip is another frequent offender. When mucus from the nasal passages drains down the back of the throat, it can irritate the tissues there and trigger throat discomfort. One study of patients with chronic idiopathic postnasal drip found that throat discomfort was the most frequently associated symptom, reported by nearly three-quarters of patients.5PubMed Central. Clinical Aspects of Chronic Idiopathic Postnasal Drip: An Entity Not to Be Overlooked The irritation involves not just the physical contact of mucus but also inflammatory mediators and sensitized nerve endings that amplify the sensation of discomfort.6PubMed. Current perspectives on rhinitis, postnasal drip, and cough If your throat hurts mostly in the morning or after lying down, postnasal drip should be high on your list of suspects.
Environmental irritants deserve a mention too. Dry indoor air during winter, breathing through your mouth while sleeping, shouting or singing for extended periods, and exposure to smoke or chemical fumes all irritate the throat lining. Even secondhand exposure to e-cigarette aerosol has been associated with throat dryness and soreness in studies evaluating participant-reported symptoms.7PubMed Central. Health Effects from Secondhand Exposure to E-Cigarettes: A Systematic Review of Peer-Reviewed Articles from 2004–2024 If your sore throat tracks with a change in environment rather than a change in how you feel overall, the cause is more likely mechanical or chemical than infectious.
How Doctors Figure Out Whether It’s Strep
Because viruses and bacteria require completely different treatment approaches, identifying the cause of a sore throat is the critical first step. Doctors use a combination of clinical scoring and laboratory testing to decide whether strep is likely.
The most widely used clinical tool is the Centor score, which assigns one point each for fever, tonsillar exudates (those white patches on the tonsils), swollen and tender lymph nodes at the front of the neck, and the absence of a cough. A score of three or four makes strep more likely, though even at those higher scores, the probability isn’t overwhelming. A systematic review validating the Centor score in primary care found that a score of three or above had reasonable specificity, with post-test probability for strep ranging from roughly 12% to 40% depending on how common strep is in the community at the time.8PubMed Central. Predicting streptococcal pharyngitis in adults in primary care: a systematic review of the diagnostic accuracy of symptoms and signs and validation of the Centor score That means even with the highest clinical scores, many patients still don’t have strep, which is why testing matters.
Rapid antigen detection tests, the “rapid strep test” you’ve likely had done at a doctor’s office, deliver results in minutes. Modern versions perform well: one evaluation found a sensitivity of about 99% and specificity around 96%, with excellent agreement with traditional culture.9PubMed Central. Comparative Evaluation of Strep A Throat Swab Culture Results Using the RapidFor™ Strep A Rapid Test Kit Older rapid tests were less sensitive. A study using an earlier generation kit found a single rapid test had a sensitivity closer to 88%, improving to about 96% when a negative rapid test was followed up with a backup culture.10PubMed. Evaluating the American Academy of Pediatrics diagnostic standard for Streptococcus pyogenes pharyngitis: backup culture versus repeat rapid antigen testing In children, many guidelines still recommend confirming a negative rapid test with a throat culture, because the consequences of missing strep in younger patients are more serious. Adults generally don’t need backup cultures because the risk of complications like rheumatic fever is much lower.
A modified version called the McIsaac score adjusts for age, adding a point for younger patients and subtracting one for those over 45. A recent meta-analysis comparing both scores in secondary care found that McIsaac was somewhat more sensitive than Centor at the same threshold but less specific, with overlapping confidence intervals between the two.11Clinical Microbiology and Infection. Systematic review and meta-analysis of the accuracy of McIsaac and Centor score in patients presenting to secondary care with pharyngitis For the patient, the practical takeaway is straightforward: these scoring systems help your doctor decide whether to test, not whether to treat. A positive test, not a high score, should drive the decision to prescribe antibiotics.
Treating the Pain
Whatever the cause of your sore throat, you want the pain to stop. Over-the-counter painkillers are the backbone of symptom relief, and they aren’t all equal for this job. In a head-to-head comparison using sore throat pain as the outcome measure, ibuprofen at 400 mg was significantly more effective than acetaminophen at 1,000 mg at every time point after the two-hour mark and overall.12PubMed. Sore throat pain in the evaluation of mild analgesics The likely reason is that ibuprofen reduces inflammation directly, while acetaminophen mainly addresses pain signaling without touching the swelling that makes swallowing miserable. If you can tolerate ibuprofen (people with certain stomach conditions, kidney problems, or aspirin allergies should avoid it), it’s the better first-line choice for a sore throat specifically.
An option you’re less likely to know about is a short course of corticosteroids. A Cochrane review of the evidence found that a single dose of corticosteroids, added on top of usual care, more than doubled the chance of complete pain resolution at 24 hours. It also reduced the average time to the start of pain relief by about six hours and cut the time to complete resolution by nearly twelve hours.13PubMed Central. Corticosteroids as standalone or add‐on treatment for sore throat A clinical practice guideline in the BMJ supported this, noting high to moderate quality evidence for the benefits of corticosteroids in reducing pain severity and shortening time to relief.14BMJ. Corticosteroids for sore throat: a clinical practice guideline This doesn’t mean you should ask for steroids every time your throat hurts, but for severe sore throat that’s interfering with eating, drinking, or sleeping, it’s worth discussing with your doctor. Dexamethasone, typically as a single oral dose, is the steroid used most commonly for this purpose.
Home remedies like warm salt-water gargles, honey in tea, cold fluids, and throat lozenges have less rigorous evidence behind them but remain popular for a reason: they provide temporary comfort without side effects. Staying hydrated is genuinely important when your throat hurts, because dry mucous membranes amplify pain.
Red Flags That Need Urgent Attention
Most sore throats are nuisances, not emergencies. But a small percentage signal something dangerous, and recognizing the warning signs could save your life or prevent serious complications.
A peritonsillar abscess occurs when a pocket of pus forms next to the tonsil, typically as a complication of tonsillitis. The hallmarks are severe pain that’s much worse on one side, difficulty opening the mouth (trismus), fever, and a muffled “hot potato” voice.15PubMed Central. Ageusia: A Symptom of Peritonsillar Abscess? On examination, the swelling is usually visible on one side of the throat. This needs drainage and antibiotics, not just waiting it out. If left untreated, a peritonsillar abscess can lead to necrotizing soft tissue infection spreading to the neck and chest wall, a rare but life-threatening complication that requires aggressive surgical treatment.16PubMed. Neglected peritonsillar abscess resulting in necrotizing soft tissue infection of the neck and chest wall
Acute epiglottitis is another throat emergency. The epiglottis is the flap of tissue that covers your airway when you swallow. When it becomes severely inflamed, usually from infection, it can swell enough to obstruct your airway. Epiglottitis can occur at any age and presents with severe sore throat, difficulty swallowing, drooling, a high fever, and a sense that it’s getting harder to breathe. The voice may sound muffled, and the person often leans forward to try to keep the airway open.17PubMed Central. Acute epiglottitis: Trends, diagnosis and management This is a call-an-ambulance situation. Early diagnosis and rapid intervention are necessary because the risk of complete airway closure is real.
Other red flags that warrant prompt medical evaluation include:
- Inability to swallow liquids: This suggests severe swelling that could worsen.
- Difficulty breathing or noisy breathing: Any sign that the airway is compromised requires immediate attention.
- Drooling: Often means swallowing has become too painful or physically impossible.
- Neck stiffness or swelling: Could indicate a deep space infection spreading beyond the throat.
- Sore throat lasting more than two weeks: Persistent pain without improvement can signal something other than infection, including rare conditions that need investigation.
Why Antibiotics Aren’t Always the Answer
One of the most common frustrations with sore throat visits is leaving the doctor without an antibiotic prescription. This feels wrong when you’re in pain, but the logic behind it is sound. Since most sore throats are viral, and antibiotics have zero effect on viruses, prescribing them for every sore throat would expose people to side effects and allergic reactions without benefit. More broadly, antibiotic overuse drives antimicrobial resistance, which is now a major global public health challenge. Overprescribing in primary care, where viruses cause most infections, is a significant contributor to resistance patterns that make treating genuinely bacterial infections harder.18PubMed Central. Antimicrobial resistance: risk associated with antibiotic overuse and initiatives to reduce the problem
When strep is confirmed, though, antibiotics are clearly warranted. They shorten the duration of symptoms by about a day, reduce the risk of spreading the infection to others, and most importantly, prevent rare but serious complications. The most worrisome of these is acute rheumatic fever, an autoimmune condition triggered by the body’s response to group A strep. The immune system’s antibodies and T-cells, originally directed at the bacterium, cross-react with the body’s own tissues, particularly the heart, leading to inflammation that can damage heart valves permanently.19bioRxiv. Immunotherapeutic strategy to prevent progression and complications of acute rheumatic fever Rheumatic fever has become rare in high-income countries thanks in large part to prompt antibiotic treatment of strep, but it remains a significant problem in parts of the developing world.
Unusual Causes Worth Knowing About
A handful of less common conditions can produce throat pain that masquerades as something ordinary. Glossopharyngeal neuralgia is a nerve condition that causes severe, sharp bursts of pain in the back of the throat, the base of the tongue, the tonsil area, or beneath the angle of the jaw. The pain comes in paroxysms, meaning sudden intense episodes that can be triggered by swallowing, coughing, or talking. It’s rare and frequently misdiagnosed.20PubMed Central. An uncommonly common: Glossopharyngeal neuralgia If you experience stabbing throat pain that comes and goes in electric-shock-like episodes, this is worth bringing up with your doctor, because the treatment pathway is entirely different from infection management.
Acute HIV infection can also present as a febrile pharyngitis, which is medical terminology for a sore throat with fever. In documented clusters, initial HIV infection produced sudden high fever, a bright red sore throat, and extreme fatigue after an incubation period of three to five weeks, sometimes accompanied by a rash. The acute illness lasted four to seven days and was followed by mild lymph node swelling.21PubMed. Febrile pharyngitis as the primary sign of HIV infection in a cluster of cases linked by sexual contact This presentation looks so much like mononucleosis or a severe viral illness that it goes unrecognized unless there’s a specific reason to test. If you develop a severe sore throat with high fever and fatigue after a potential exposure, testing for HIV is reasonable and important, since early detection dramatically improves long-term outcomes.
The Recurrent Sore Throat Problem
Some people seem to get sore throats constantly. They finish one round of antibiotics only to be back in the clinic weeks later with the same symptoms. One reason this happens is that bacteria living deep inside the tonsils may differ from what’s growing on the tonsil surface. Research comparing surface and deep tonsillar cultures found that in nearly half of cases, a different pathogen was present in the interior of the tonsil compared to what the surface swab detected.22The Journal of Laryngology & Otology. Surface tonsillar microflora versus deep tonsillar microflora in recurrent acute tonsillitis Antibiotics chosen based on a surface culture may clear the bacteria you can reach while leaving the deeper organisms untouched, setting the stage for another infection. This mismatch between surface and deep bacterial populations is one of the reasons tonsillectomy remains a treatment option for people with genuinely recurrent tonsillitis: it removes the reservoir entirely.
Recurrent sore throats can also be non-infectious. If your throat hurts repeatedly but throat cultures keep coming back negative and you never have a fever, the likely culprits are reflux, postnasal drip, allergies, or environmental factors rather than recurrent infection. Treating the wrong cause guarantees the problem continues. A conversation with your doctor about the pattern of your symptoms, when they occur, what makes them worse, and what other symptoms accompany them, is more productive than another round of antibiotics aimed at a bacterium that may not be there.