Lip Swelling Meaning, Causes and Symptoms

December 15, 2017

Why are my lips swollen? Can allergies, trauma, canker sores, sunburn, cold sores, insect bites, angioedema, ingrown hair, or pimples make them swell? What about the case of sudden unexplained lip swelling overnight or when you wake up in the morning?


Lip swelling (edema) refers to distention or enlargement of one spot or the whole of the upper lip, lower or both the lips caused by mainly tissue inflammation and buildup of fluid. Today, we are focusing on what can cause this condition.

Symptoms-lip swelling

The most common symptom is the distention (fattening or enlargement) which might be painful (hurts) or itchy at times. In extreme cases, this enlargement might make drinking, talking, eating, or mouth opening difficult.

Other symptoms that might accompany the swelling include blistering, chapping, pain, redness, numbness, headache, chills, pus (yellow or with dark pus). Also, watery eyes, itchy eyes, runny nose, discoloration, and fatigue among many others that will be tied to the specific a certain cause.

Causes-lip swelling

When you suddenly have a lip swelling, it is normal to wonder why it is swollen and what could have caused it?  Well, there are many causes. Some of which are less serious and might disappear quickly while others might be an indication of more serious underlying conditions or disease that can be life-threatening. It is good to ensure you know the root cause and get proper treatment.

So, what are some of the common reasons for or what could be behind the swelling you have?

Allergic reaction

This is a common symptom for a number of allergic reactions to various allergens that include certain foods, pet dander, pollen grains, some lip care products, and other allergens.

When caused by an allergy,  it is likely to happen suddenly and it can be mild or severe after you come in contact with the allergen.

Furthermore, some of the allergic reaction symptoms might affect other parts of your body especially the eyes, cheeks, mouth, tongue, face, and nose areas. The common allergens include the following:


Some common foods that might cause allergic reactions that will culminate in a lip that is swollen among other symptoms. They include nuts, strawberries, mushrooms, egg whites, fish, sesame seeds, shellfish, and dairy products.


Direct latex contact can cause skin irritation and consequently allergic reactions. Therefore, if your lips touch latex, it is common to expect to swell and be itchy and at times have rashes. Letting balloons, children’s toys, gloves and other products made from latex come in contact with your lips is one way you can end up with this problem.

Penicillin allergy

When caused by penicillin allergy, expect other symptoms such as rash, itching, and hives. You will know it is the cause if you have had a penicillin injection or antibiotics.

Lip care products allergies

The various products such as lipsticks, balms, chapsticks, glosses might contain ingredients you are allergic to.

Anaphylaxis allergy

If you have anaphylaxis, you need to seek immediate medical attention since it is life-threatening and severe allergic reaction whose symptoms include

  • swollen lip,
  • swollen mouth or throat
  • Hives or rashes
  • itchy face or eyes
  • Breathing and swallowing difficulties (including short breath and chocking)
  • Intense distress
  • Swollen tongue

If ignored, anaphylaxis can “develop quickly, triggering an increased heart rate, weakness, a drop in blood pressure, shock and, ultimately, unconsciousness and death” [].

Note: If you have allergic reactions, antihistamines, and medications such as Benadryl might be of some help.


Angioedema, which is the “swelling of the tissue beneath the skin, and this is often concentrated around the eyes and lips” [] can be a cause. Especially in deeper skin layers and affects other body parts including feet, hands, genitals, eyelids, etc.

Most people with angioedema will tend to complain of swollen lips for no reason. It can happen overnight when they wake up in the morning. Recurrent (idiopathic angioedema) attacks or swelling and numbness.

Angioedema is commonly caused by allergic reactions, with food allergies being the most often cause. The problem has a prevalence between 5% and 8% in children, while in adults it is much lower, standing at about 1-2%.

Angioedema can also be caused by animal dander, exposure to sunlight (sunburnt lips), heat or cold, bites from insects. Also medications such as blood pressure medications, antibiotics, and nonsteroidal anti-inflammatory drugs.

Finally, there is rare hereditary angioedema can also cause this problem. It is due to a faulty gene that affects very few people. Furthermore, too much stress and infection can cause angioedema.

Stomatitis and infections

Stomatitis is a general terminology that refers to a sore and inflamed mouth and lips that often affect someone’s ability to talk, eat, or sleep well. A number of viral, fungi, bacterial infections, and other conditions is what causes stomatitis. Common causes being canker sores, cold sores, angular cheilitis, as well as general lip irritations.

Herpes simplex virus or cold Sores

Herpes simplex, specifically the herpes type 1 also known as oral herpes or cold sores is known to cause sores and swollen blistered around your mouth and lips. The blisters are often pus-filled and will affect the various part of your body too.

Cold sores are generally painful, they last for 7- 14 days and they come with flu and cold-like symptoms that might include a sore throat and nasal congestion.

Canker sores

Canker sore refers to a yellow or pale ulcer that has “a red outer ring or a cluster of such ulcers in the mouth, usually on the cheeks, tongue, or inside the lip” []. They often result in swelling when they are is on your inner or outer lip.

Canker sores are also painful, have a tingling feeling, and last between 5-10 days. They also have a tendency of coming back again. Furthermore, they do not come with fever but you might have other symptoms such as swollen lymph nodes, fever, physical sluggishness, etc.

Angular Cheilitis or angular stomatitis

Angular cheilitis, also known as angular stomatitis refers to an inflammation on typically both the corners of your mouth but can at times affect one mouth corner. It is characterized by “pain in the lips, cracked lips, ulceration, reddened skin, and tenderness at the involved area” []. A dry mouth is common when you have angular cheilitis.


This is a bacterial skin infection which when it affects the skin around your lips, the infection can cause swelling.


The other common cause is trauma. Physical injuries cause swelling. For instance, you could have a swollen lip after biting it or being hit by a blunt object. The other common causes of traumatic lip swelling include

  • Dental appliances such as braces
  • Oral surgical procedures
  • Burning  with very hot drinks and foods
  • Surgeries
  • Too much tobacco chewing can cause swelling including on your mouth.
  • Lip piercings
Sunburned lips

Excessive exposure to UV sunlight can also cause blistered, itchy, swollen, and chapped lips. This is a mild cause that is not life-threatening. Besides UV sunlight, a dry, windy, and arid weather condition conditions can cause licking, peeling, and swelling. This is why you might have this problem after exposure to a bad air condition.

Severe malnutrition

Poor general nutrition and lack of vitamins, especially vitamin B have been associated with lip swelling. This often affects corners.


A severe pimple or bump can cause a random swelling especially on the spots where it develops. There are many causes as well as treatments of pimples on lips.

Other causes

Besides the above causes, this problem can be caused by the following:

  • Exercising
  • Some medications
  • Insect bites
  • Bee and wasp stings
  • Fluid retention that often happens during pregnancy
  • Lip cancer
  • Obesity
  • Organ failure e.g. liver, kidney, or heart
  • “Preeclampsia (serious condition of pregnancy marked by swelling, high blood pressure, and protein in the urine)” []
  • Reaction to blood transfusion
  • Ingrown hair is common for people who remove mustache hairs wrongly or using blunt razors.
  • Diabetic people are prone to mouth infections as well as infections that cause the swelling.

These are the most common causes of swollen lips. There could be medical conditions that could also cause this swelling including on your tongue, mouth as well as other parts of your body.