Laryngitis happens when your vocal cords become swollen and irritated, and the most common way to get it is from a viral infection like a cold or the flu. But viruses aren’t the only trigger. Overusing your voice, breathing in irritants, and even stomach acid can inflame your vocal cords. What causes it also determines how long it lasts: acute laryngitis clears up within a few weeks, while chronic laryngitis lingers beyond three weeks and usually points to an ongoing irritant.
What Happens Inside Your Throat
Your vocal cords are two small bands of muscle and tissue that vibrate together when air passes through them, producing sound. When those cords swell, everything changes. The added mass makes them vibrate unevenly, with less of the smooth wave-like motion that produces a clear voice. Your vocal cords also stay open longer during each vibration cycle instead of snapping shut crisply, which is why your voice sounds breathy and hoarse.
The swelling raises what’s called the phonation threshold pressure, meaning your body has to push harder just to get the cords vibrating at all. This is why talking feels effortful during laryngitis. When the swelling is severe enough that you simply can’t generate enough pressure to vibrate the cords, you lose your voice entirely. Making things worse, many people instinctively force their voice harder to compensate, which creates extra friction between the already inflamed cords and delays recovery.
Viral Infections Are the Top Cause
The vast majority of acute laryngitis cases come from the same viruses that cause upper respiratory infections. Common cold viruses, influenza and parainfluenza, adenoviruses, RSV, and COVID-19 can all inflame the larynx. Less commonly, measles, chickenpox (or shingles in adults), and whooping cough cause it too. The pattern is straightforward: a virus infects the tissue around your vocal cords, your immune system sends white blood cells to fight it off, and the resulting inflammation makes the cords swell.
This is why laryngitis so often arrives alongside a sore throat, runny nose, or cough. It’s part of the same infection spreading through your upper airways. You “catch” this type of laryngitis the same way you catch a cold: through respiratory droplets, touching contaminated surfaces, or close contact with someone who’s sick.
Voice Overuse and Vocal Strain
You don’t need a virus to get laryngitis. Singing for hours, shouting at a concert, talking loudly in a noisy environment, or simply speaking for extended periods can do it. When you overuse your voice, you increase the force with which your vocal cords press together. That repeated contact and friction causes the tissue where the cords meet to swell, producing the same hoarseness you’d get from an infection.
Teachers, singers, coaches, call center workers, and anyone who relies heavily on their voice is particularly vulnerable. Even a single night of intense yelling can trigger an episode. Habitual throat clearing is another underappreciated cause. It forces your vocal cords to vibrate abruptly and can worsen swelling that’s already there.
Stomach Acid Reaching Your Throat
Acid reflux that travels all the way up to the throat, known as laryngopharyngeal reflux, is one of the most common causes of chronic laryngitis. It only takes a small amount of stomach acid and digestive enzymes like pepsin to damage the delicate tissue around your vocal cords. Unlike your esophagus, your throat doesn’t have a protective lining designed to handle acid, and it lacks the clearing mechanisms that wash reflux away. So the acid sits there longer and does more damage.
This type of reflux can also interfere with your throat’s normal ability to clear mucus and fight off infections, making you more susceptible to further irritation. Some people inhale tiny acid particles into their airways during sleep without realizing it, which can cause additional inflammation deeper in the respiratory tract. Many people with this condition don’t experience classic heartburn, so the connection between their hoarseness and reflux often goes unrecognized.
Smoke, Chemicals, and Other Irritants
Breathing in irritants is a direct route to laryngeal inflammation. Cigarette smoke is the most well-known culprit, whether you’re the smoker or regularly exposed to secondhand smoke. Chemical fumes in workplaces, air pollution, and allergens can also trigger chronic irritation. Alcohol and caffeine contribute by drying out and irritating throat tissues. If you’re regularly exposed to any of these, the inflammation never fully resolves, which is how acute laryngitis becomes chronic.
Fungal Infections and Other Rare Causes
Occasionally, laryngitis is caused by a fungal infection rather than a virus. Candida, the same fungus responsible for oral thrush, can colonize the larynx. This is especially common in people who use inhaled corticosteroids for asthma or COPD, because the medication suppresses the local immune defenses in the throat. People with diabetes, HIV, cancer, or anyone taking antibiotics or medications that cause dry mouth also face a higher risk. Smoking further increases susceptibility. If you use an inhaler, rinsing your mouth thoroughly after each use helps reduce this risk.
Why Antibiotics Don’t Help
Because most laryngitis is viral, antibiotics are ineffective for the typical case. A Cochrane review examining three clinical trials found no meaningful benefit. In one study, penicillin performed no better than a placebo when researchers recorded and measured patients’ voices over several weeks. In another, erythromycin showed no significant difference in objective voice measurements compared to no treatment. While one trial showed a small subjective improvement at one week, that difference disappeared by the second week. The overall evidence quality was rated very low. Requesting antibiotics for routine laryngitis won’t speed your recovery and contributes to antibiotic resistance.
How to Recover Faster
The main treatment for acute laryngitis is resting your voice. A common recommendation is five to seven days of reduced voice use, though there’s no single standardized protocol. Voice rest beyond one week tends to be counterproductive for most people. A practical rule: speak softly enough that you could be heard by someone standing within arm’s length, and avoid shouting, singing, or projecting your voice.
Whispering is more complicated than most people realize. A gentle, relaxed whisper is acceptable, but a loud “stage whisper,” the kind you’d use across a room, actually increases tension in the larynx and can make things worse. For significant vocal cord injuries, some specialists recommend avoiding even whispering entirely.
Beyond voice rest, staying hydrated helps keep the vocal cord tissue from drying out, and avoiding irritants like cigarette smoke, alcohol, and caffeine reduces further inflammation. Humidified air can also soothe irritated airways. Most cases of acute viral laryngitis resolve on their own within one to two weeks.
Signs That Need Medical Attention
Hoarseness lasting longer than four weeks warrants a medical evaluation, including direct visualization of the vocal cords. More urgent red flags include difficulty breathing, stridor (a high-pitched sound when inhaling), coughing up blood, a new lump in the neck, or hoarseness following surgery or intubation. A history of tobacco use combined with persistent voice changes also raises concern, since these symptoms can overlap with more serious conditions affecting the larynx.