Possible Causes of Swollen Lips

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Several conditions can cause swollen lips. While some of these conditions can be serious or even life-threatening, others may resolve on their own. You should see your healthcare provider any time that the swelling cannot be explained, does not improve after a few days, is accompanied by difficulty breathing, or if you suspect any of the life-threatening conditions covered below.

Swollen lips causes
Verywell / Nusha Ashjaee


Swollen lips are a characteristic of oral allergy syndrome (OAS), a cross-reactive type allergy in which certain foods trigger a tingling mouth and allergic inflammation when eaten. Rarely is OAS is considered serious and usually resolves on its own after a few minutes or an hour or so.

Angioedema is another more concerning allergic reaction related to something you've eaten, an insect bite, pollen allergies, or a medication you've taken. It causes swelling of the lips, face, and tongue, which usually occurs rapidly.

It can also sometimes be accompanied by redness or bumps (hives). Due to the swelling, you may have difficulty talking.

Angioedema can be life-threatening if it affects the windpipe (larynx). Call 911 if the swelling is accompanied by wheezing, difficulty breathing, or bluish lips, fingers, or skin (cyanosis).

Angioedema emergencies can be treated with epinephrine—known as a "sympathomimetic" drug that stimulates alpha and beta adrenergic receptors.

If you have had this type of reaction, you should carry epinephrine (EpiPen) or a single-dose epinephrine syringe (Symjepi) with you in case of an emergency.


Trauma to the face or lips—for example, burning your lips on hot food or being hit in the mouth—can cause swelling. In minor cases, the swelling can usually be controlled using a cold pack and will resolve in a few days.

If you have a lip laceration that is deep, bleeds excessively, is causing a lot of pain, or is larger than 1/4 inch (6 millimeters), see your healthcare provider as soon as possible.

If the injury occurred more than 24 hours earlier, your healthcare provider will likely not be able to apply stitches, especially if the wound is overly swollen or at risk of infection. In this case, your healthcare provider will clean your wound and schedule a repair in a couple of days.

If stitches are close to your lips, you should follow these care guidelines:

  • Eat a soft diet for two to three days.
  • Avoid spices in your food until the wound is healed.
  • Rinse your mouth with water area every meal to remove debris from the wound
  • Do not drink with a straw as the sucking motion creates negative pressure that can damage the repair.

Chapped or Sunburned Lips

Very chapped lips may become swollen. This is generally caused by licking your lips too much, being outside in windy, sunny, or arid weather, or just living in a dry climate. To prevent this from occurring, you can try any or all of the following:

  • A lip balm containing petroleum jelly or beeswax
  • Lip products with sunscreen
  • Wearing a hat
  • Avoid licking your lips
  • Avoid picking at any dry, flaky skin


Some infections may cause lip swelling, including those caused by fungal infections, viruses, or bacteria. Sometimes chapped, cracked lips allow germs to infect this area. This can cause redness, soreness, and some swelling. In the case of an infection, treatment will depend on the germ causing it and should be managed by your healthcare provider.

An infection should be considered serious if it is accompanied by a high fever (over 100.4 F), shaking chills, nausea or vomiting, or a pus discharge. See your healthcare provider or go to the nearest urgent care center.


A mucocele usually appears more like a bump on the lip rather than generalized swelling, but they can vary in appearance. Mucoceles are cysts that occur from biting the lip or trauma to the lip that results in damage to a salivary gland. The fluid then backs up or pools under the skin in that area and forms a bump.

Mucoceles are not considered a serious health problem, but some may be bothersome and they may have to be surgically removed or lanced and drained.

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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. Pollen food allergy syndrome.

  2. Kaplan AP, Greaves MW. Angioedema. J Am Acad Dermatol. 2005;53(3):373-88. doi:10.1016/j.jaad.2004.09.032

  3. Senthilkumar B, Mahabob MN. Mucocele: An unusual presentation of the minor salivary gland lesionJ Pharm Bioallied Sci. 2012;4(Suppl 2):S180-S182. doi:10.4103/0975-7406.100265

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