Why Are My Lips Swollen?

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Swollen lips can be caused by allergic reactions, injuries, chapping or sunburn, infections, and cysts called mucoceles. Some causes can be serious or even life-threatening, while others may be minor and resolve on their own.

The swelling comes from either inflammation or built-up fluid under the skin. This article looks at some of the causes of swollen lips and when you should see your healthcare provider.

Swollen lips causes
Verywell / Nusha Ashjaee


Swollen lips are a symptom of oral allergy syndrome (OAS). When you have this type of allergy, certain foods trigger a tingling mouth and allergic inflammation.

OAS is rarely serious. Reactions usually resolve on their own within an hour.

Angioedema is a more concerning allergic reaction. It can be triggered by a few things, including:

Symptoms of angioedema usually appear rapidly and may include:

  • Swelling of the lips, face, tongue, hands, feet, and genitals
  • Hives
  • Dizziness
  • Abdominal pain

The swelling may make it hard to talk or even breathe.

Angioedema can be life-threatening if it affects the windpipe. Call 911 if the swelling is accompanied by:

  • Wheezing
  • Difficulty breathing
  • Cyanosis or bluish lips, fingers, or skin

Angioedema emergencies can be treated with epinephrine. This drug helps the muscles in your airway relax so you can breathe.

Once you've had this type of reaction, you should carry an EpiPen (a multi-use epinephrine auto-injector). Symjepi is a single-dose option. Have one of these medications on hand at all times.


Trauma to the face or lips can cause swelling. This might happen if you burn your lips on hot food or are hit in the mouth.

In minor cases, the swelling can be controlled with a cold pack. It will usually resolve in a few days.

Large Cuts

If you have a large cut on your lip, it's important to get medical care within 24 hours. If the injury is older than that, it can't be treated with stitches—especially if it's very swollen or there's a risk of infection.

If you go in after the 24-hour mark, your healthcare provider can only clean the wound and schedule a repair in a few days.

Stitches Near Your Lips

If you have stitches close to your lips, it's important to:

  • Eat soft foods for two or three days.
  • Avoid spicy food until the wound heals.
  • Rinse your mouth with water after every meal to remove food particles from the wound.
  • Don't drink with a straw. The sucking motion creates negative pressure that might damage the repair.

See your healthcare provider at once if you have a cut on your lip that is:

  • Deep
  • Bleeds excessively
  • Causes a lot of pain
  • Is larger than 1/4 inch (6 mm)

Chapped or Sunburned Lips

Very chapped lips or sunburned lips may become swollen. Your lips may sunburn right along with the rest of your skin.

Your lips can get chapped if you:

  • Live in a dry climate
  • Lick your lips a lot
  • Spend time outside in windy, sunny, or arid weather

You can prevent chapping by:

  • Using a lip balm containing petroleum jelly or beeswax
  • Not licking your lips
  • Not picking at dry, flaky skin on your lips

You can keep your lips from getting sunburned by:

  • Choosing lip products with sunscreen
  • Wearing a hat
  • Avoiding prolonged sun exposure


Some infections may cause lip swelling. This includes infections caused by funguses, viruses, or bacteria. Infected lip piercings are somewhat common.

Sometimes, germs can infect chapped, cracked lips. This can cause redness, soreness, and some swelling.

If you have an infection, treatment will depend on what's causing it. Infections should always be treated by a healthcare provider.

Is Your Infection Serious?

Signs of a serious infection include:

  • A fever over 100.4 F
  • Chills that make you shake
  • Nausea or vomiting
  • Pus drainage

If you have any of these symptoms, see your healthcare provider or get urgent medical care.


Mucoceles (mucous cysts) are cysts that form after you bite your lip or have an injury that damages a salivary gland. They're not a serious health problem, but they can be bothersome.

Mucoceles are most common on the inner surface of the lips, inside the cheeks, or on the underside of the tongue. They vary in appearance, but they usually look like bumps rather than generalized swelling.

These cysts typically go away on their own. If they don't, or if they interfere with things like talking or eating, you can have them surgically removed or lanced (sliced open) and drained.

When to See a Healthcare Provider

You should see a healthcare provider about your swollen lip(s) if:

  • You have swelling that can't be explained
  • The swelling doesn't improve after a few days
  • You also have difficulty breathing
  • You suspect an infection
  • You suspect a severe allergic reaction


A few things can cause swollen lips. Some are much more dangerous than others.

An oral allergy usually improves within an hour. Angioedema is a serious allergic reaction that also causes wheezing and trouble breathing. Get emergency medical care if you suspect andioedema.

Other causes of swollen lips include injuries, chapped or sunburned lips, mucoceles, and infection. Make sure to see your doctor if you have a deep cut or signs of infection like fever, chills, and vomiting.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American College of Allergy, Asthma, and Immunology: Allergist. Pollen food allergy syndrome.

  2. National Health Service. Overview: Angioedema.

  3. Sinha R, Sarkar S, Khaitan T, Kabiraj A, Maji A. Nonsurgical management of oral mucocele by intralesional corticosteroid therapyInt J Dent. 2016;2016:2896748. doi:10.1155/2016/2896748

Additional Reading

By Kristin Hayes, RN
Kristin Hayes, RN, is a registered nurse specializing in ear, nose, and throat disorders for both adults and children.