What causes sudden lip swelling?

If your lip suddenly swelled up, your first question is probably whether this is an emergency. Most of the time, it isn't — an allergic reaction, an injury, an insect sting, an infection or a tooth or gum problem are the usual causes. But a few symptoms mean you should stop reading and call 911 instead. 

What you will learn in this article: 

• Allergic reactions and angioedema can make a lip swell quickly. 

• A bite, cut, burn or other injury may cause swelling. 

• A tooth abscess or another infection can cause painful swelling that needs prompt care. 

• Trouble breathing or swelling of the tongue or throat means you should call 911. 

If your lip is swollen but you are breathing normally, schedule an appointment with an Aspen Dental provider. Your care team can check for a dental cause and help you decide what to do next. If you have trouble breathing or your tongue or throat is swelling, call 911. 

What usually causes sudden lip swelling? 

Sudden lip swelling can have several causes. It may follow an allergic reaction, an insect sting, an injury or an infection. Sometimes the cause is not clear at first. When the swelling started and what other symptoms you have can help a dental provider or doctor find the cause. 

Could it be an allergic reaction or angioedema? 

An allergic reaction can make your lip swell quickly. This may happen after eating a certain food, taking medicine or being bitten or stung by an insect. 

Angioedema is swelling in deeper tissue. It often affects the lips or the area near the eyes. According to MedlinePlus, possible triggers include foods, insect bites, pollen and some medicines. Sometimes no cause is found. 

Angioedema can also affect the throat. If the swelling makes it hard to breathe, get emergency help right away.¹ 

Could an injury cause your lip to swell? 

A bump, bite, cut or burn can make your lip swell. Sports injuries and falls can do the same thing. 

Your lip may also feel puffy after dental work because it is numb. Biting the numb skin without feeling it can cause a sore tongue or lip after a filling. Contact your dental provider if the swelling gets worse, becomes painful or does not begin to improve. 

What should you do if a dental problem might be the cause? 

If you also have any of the symptoms above, a dental problem may be the cause. Dental X-rays may help identify which tooth is causing the problem.² 

If the swelling and cracking are at the corners of your mouth, you may have cracked lip corners, which is a different condition. Your dental care team can examine the area and help find the cause. 

Could an infection be behind the swelling? 

An infection near your lip or mouth can cause swelling. A tooth abscess is one possible source. It is a pocket of pus caused by a bacterial infection in or around a tooth. 

According to MedlinePlus, signs of a tooth abscess may include severe tooth pain, fever, pain when chewing, a bad taste, swollen gums, swollen neck glands or swelling in the jaw. Treatment may include antibiotics, a root canal, draining the abscess or removing the tooth. An untreated abscess can spread and lead to life-threatening complications.² 

Get prompt dental care if you think you have abscess swelling. Do not wait for severe pain or swelling to go away on its own. 

Could a bug bite cause sudden lip swelling? 

A bite or sting near your mouth can make your lip swell. The swelling may stay near the bite, or it may be part of a larger allergic reaction. You may also notice redness, itching or hives. 

Watch for symptoms in other parts of your body; signs of a broader allergic reaction are covered in the emergency symptoms below. 

When is lip swelling a medical emergency? 

Call 911 if you have: 

• Trouble breathing 

• Swelling of your tongue or throat 

• Tightness in your throat or trouble swallowing 

• Wheezing or shortness of breath 

• Dizziness, fainting or a weak pulse 

MedlinePlus notes that anaphylaxis can begin very quickly and may be life-threatening. A serious allergic reaction requires immediate emergency care.³ 

Fever, severe tooth pain or worsening swelling around your mouth or jaw also needs prompt medical or dental care. 

If lip swelling comes with tooth pain, swollen gums, a bad taste or jaw swelling, talk with your dental provider promptly. They can examine your teeth and gums, identify a possible dental cause and recommend the next step. 

What causes sudden lip swelling? FAQs 

Still have questions about sudden lip swelling? These answers cover a few common concerns. 

Can stress cause sudden lip swelling? 

Stress is not usually a direct cause of sudden lip swelling. However, a stress-related habit such as biting your lip may injure it and cause swelling. A dental provider or doctor should check swelling that happens without a clear injury. 

How long does allergic lip swelling last? 

How long the swelling lasts depends on its cause and severity. According to MedlinePlus, angioedema that does not affect breathing often goes away within a few days.¹ Contact a doctor if this is your first episode, the swelling is severe or it does not improve. Call 911 if you have trouble breathing. 

Should I go to the ER or see my dental provider first? 

Call 911 if the swelling affects your tongue, throat or breathing. If you are breathing normally and the swelling seems connected to a tooth, filling or gum problem, contact your dental provider. 

Can lip swelling keep coming back? 

Yes. Lip swelling may happen again, especially if you come into contact with the same trigger. Sometimes the cause is not clear. Tell your dental provider or doctor if the swelling keeps returning. 

Can lip swelling point to a health problem beyond your mouth? 

Yes. Lip swelling is not always caused by a dental problem. A doctor can review your symptoms, medicines and possible triggers when the swelling lasts or returns. 

Sources 

¹ National Library of Medicine, MedlinePlus, Medical Encyclopedia: “Angioedema.” https://medlineplus.gov/ency/article/000846.htm 

² National Library of Medicine, MedlinePlus, Medical Encyclopedia: “Tooth abscess.” https://medlineplus.gov/ency/article/001060.htm 

³ National Library of Medicine, MedlinePlus: “Anaphylaxis.” https://medlineplus.gov/anaphylaxis.html