Waking up with a swollen lip may cause concern to some people. A swollen lip can happen for several reasons, including an allergic reaction, an injury, or another medical condition.

A person may be able to identify what has caused their lips to swell by thinking about what activities they did or what food they ate the day before.

Keep reading to learn more about the causes behind waking up with a swollen lip, and what person can do to treat it.

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Waking up with a swollen lip may be due to something a person ate or did the previous day.

Below are some of the more common possible causes of waking up with a swollen lip.


Angioedema refers to the rapid swelling of an area under the skin. According to the National Health Service (NHS) in the United Kingdom, angioedema commonly affects the eyes and lips. However, the swelling does not last long, usually clearing within 48 hours.

It is similar to a skin condition called urticaria, or hives, but it affects different parts of the skin. Angioedema and urticaria can develop at the same time.

Urticaria causes a rash on the skin, while angioedema typically affects the skin and the tissues beneath the skin, or the subcutaneous and submucosal layers.

Symptoms of angioedema include:

  • swollen skin
  • red skin
  • itchy rash (hives)
  • painful and tender skin


Allergic reactions to food, medication, or certain materials, such as latex, can cause the lip to swell. Allergic reactions to food usually develop within minutes of coming into contact with the food. However, some reactions can take hours to develop.

The American Academy of Allergy, Asthma, and Immunology (AAAAI) indicate that allergic reactions to medications may take hours or weeks to develop. This means that a person can wake up with swollen lips if they ate a particular type of food or took a medication they are allergic to many days before

Oral allergy syndrome

Oral allergy syndrome, also called pollen-food syndrome, is a type of reaction to raw fruit and vegetables and some nuts and seeds that can develop in adulthood.

Symptoms of oral allergy syndrome are an itchy mouth or tongue and swollen lips or tongue. The symptoms only affect the mouth and do not last long. Eating uncooked food is the main culprit.

If a person wakes up with swollen lips, they may have eaten food that triggered a reaction overnight or developed a medication sensitivity over time.


Severe allergic reactions are called anaphylaxis and are a medical emergency. A person with anaphylaxis may have difficulty breathing, swallowing, or speaking, and they may feel dizzy or lose consciousness.

Anyone experiencing anaphylaxis needs immediate medical treatment.


Cellulitis is a deep bacterial infection of the skin that usually affects the arms and legs, but it can develop around the mouth.

Usually, bacteria that enter the skin after damage during surgery or an injury cause cellulitis.

The symptoms of cellulitis include swelling, redness, tenderness, pain, blisters, and bruising.


The most common reason that a brace might cause swollen lips is that it can rub against the soft tissue on the inside of the lips and cheek, causing swelling and irritation.

Manufacturers make orthodontic braces from nickel, so anyone who has an allergy to the nickel may experience a reaction. However, there are alternative options to metal braces if a person does have an allergy.

If a person is hit in the mouth while wearing orthodontic braces, their lip or cheek tissue can become caught in the metal wire or brackets. Separating the lip tissue from the brace can cause more trauma to the lips, causing swelling as they heal.

Wearing a mouthguard when playing sports can protect a person’s lips or cheeks from getting caught in their braces. Using dental wax to cover parts of the braces that can cut the lips or cheeks can reduce the risk of injury and consequent swelling.


Injury to the mouth and lips can cause swelling. The lips contain a lot of blood, and they can bleed heavily. However, they also heal quickly and do not often need stitches.


A person may get sunburned after exposure to strong sunlight, tanning lamps, or sunbeds. Sunburn is an inflammatory skin reaction and can cause swelling.

If a person exposed their face to strong sunlight during the day, they might wake up with swollen lips. This is because the peak reaction for sunburn happens around 24 hours after exposure.

If a person has sunburn on their lips, anti-inflammatory medications can help reduce swelling, but they need to start this treatment before the skin changes color.

Focal dystonia

Focal dystonia is a neurological condition. It affects a particular muscle or muscle group in one area of the body, causing involuntary muscle contractions and postures.

Cranial dystonia affects muscles in the face, including the lips.

A person with oromandibular dystonia may experience difficulty swallowing, chewing, speaking, opening and closing their mouth, and have tongue spasms.

Embouchure collapse

An embouchure collapse, or embouchure dystonia, affects the lower facial muscles, tongue, jaw, and pharynx.

The embouchure is a specific position that wind and brass instrument players position their facial muscles to produce sound from their instrument.

A musician might notice the symptoms of embouchure collapse by feeling pain while playing. It can include tremors and involuntary muscle contractions of the mouth, jaw, and tongue.

Embouchure collapse may occur if a person plays their instrument too much. Stopping playing for a while will help prevent embouchure overuse and collapse. However, there is little advice on how long a person should stop playing for.

These following rare conditions may also cause a swollen lip.

Miescher-Melkersson-Rosenthal syndrome

Miescher-Melkersson-Rosenthal syndrome (MRS) is a rare neurological disorder that causes long-term swelling of the face, typically in one or both lips. It can also cause weakened facial muscles and a fissured tongue, which will look cracked, split, or folded.

Symptoms will begin with a swollen upper or lower lip. The cheeks, eyelids, or one side of the scalp may also swell. This swelling will clear up in several hours or days, but the swelling may last longer and be more severe each time it occurs. Over time, the swelling can become permanent.

Doctors think that MRS is a genetic condition. However, it can also be a symptom of other conditions, such as Crohn’s disease or sarcoidosis, an inflammatory condition that can affect any organ of the body.

Granulomatous cheilitis

Granulomatous cheilitis is a rare condition that causes the lips to swell. It is caused by:

Swelling from granulomatous cheilitis only occurs in the lips and usually begins with swelling in the upper lip. As with MRS, recurrent episodes can result in more severe swelling that lasts for more extended periods.

Oral cancer

Some types of oral cancer can cause lip swelling. Common symptoms of oral cancer may include:

  • persistent tongue and jaw pain
  • a lump in the mouth
  • thickening skin in the mouth
  • red or white patches on the gums, tonsils, or mouth lining
  • trouble swallowing or chewing
  • reduced movement in the jaw or tongue

Surgery, radiation therapy, chemotherapy, immunotherapy, and targeted drug therapy are treatment options for oral cancer. If a person experiences any of these symptoms, they should seek medical advice quickly.

Treatment for angioedema includes avoiding triggers and taking antihistamines if angioedema is due to an allergic reaction, steroid medications to reduce swelling, and having adrenaline injections if swelling is severe (anaphylaxis).

There is no treatment for hereditary angioedema, but the above treatments might help manage the swelling. Doctors may also prescribe an inhibitory medicine that can reduce the chances of swelling happening.

Not everyone with MRS will require treatment, but without treatment, each episode of swelling might worsen. People can have corticosteroid injections or take nonsteroidal anti-inflammatory medications (NSAIDs) and antibiotics to treat MRS.

For severe swelling, a doctor may recommend radiation therapy and surgery.

People with granulomatous cheilitis may take topical corticosteroids, long-term anti-inflammatory medications, or have injections of corticosteroids into the lips, or surgery.

Doctors typically treat cellulitis with antibiotics and pain relief medication. Some people may require surgery. Keeping the infected area clean and dry might also help.

To treat lip injuries at home, clean the wound with a sterile cloth, and apply pressure with a clean cloth or bandage to stop the bleeding.

Use ice to reduce swelling and pain. One article recommends applying ice to the area every 1–2 hours for 10–15 minutes for the first 24 hours after the injury. Wrap the ice in a cloth to prevent burns to the skin.

For injuries inside the lips, clean the wound with cool water for several minutes and then suck on ice to reduce swelling and pain. Wounds on the inside of the mouth heal quickly on their own.

People can treat sunburn with aloe vera, which has anti-inflammatory properties. Black tea and raw honey are other natural remedies that might provide sunburn relief. Cooling the sunburn by having cool showers, taking cool baths containing porridge oats, or applying ice or frozen peas wrapped in a cloth can also help.

A person may wake up with a swollen lip for various reasons. Trying to remember what they had done, where they had been, or what they had eaten the day before can quickly determine the cause.

If there are signs of injury, infection, or signs of a more severe illness, a person should seek medical advice quickly to start appropriate treatment as soon as they can.