One Sided Facial Swelling (Swollen Face on One Side)

Facial Symmetry

The human face is roughly symmetrical meaning that the vertical half on one side closely matches the other side. It most people it is not a mirror image but very similar. When there is a marked difference between one side of the face compared to the other then it is known as asymmetry. The size and shape of the face of determined by a number of factors, mainly genetics, body weight, general health and age. The structure of the human face is determined by the size, shape and quantity of :

  • skull bones (cranium and jaw)
  • facial muscles
  • subcutaneous fat
  • thickness and tautness of the skin

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The orientation of the jaw (mandible) in relation to the cranium may also contribute to the shape of the face. Symmetry also applies to the eyebrows, eyes, nose, lips and ears.

Enlarged Side of the Face

Although it is known that the face is symmetrical, there is one side that is slightly larger then the other. This is normal and usually not noticeable unless the face is examined closely. Most people will know which side of their face is slightly larger than the other but it is not noticeable to even  close friends and family without careful scrutiny.

Sometimes, however, the enlargement of one side of the face reaches a point where it is clearly evident and even if it does not cause any other symptoms, it can cause psychological stress.  One sided facial swelling may occur with a growth in the bone or soft tissue, accumulation of fluid, muscle enlargement, skull bone and particularly jaw displacement compared to the other side of the face. Most of these scenarios are considered to be abnormal and facial asymmetry in these instances needs to be investigated further to identify the cause and corrected. Some of these causes can be potentially life threatening, like a malignant tumor, whereas in other cases it may be uncomfortable but will not lead to severe medical complications.

Why does only one side swell?

The most common causes of one sided facial swelling is a result of inflammation. This is often referred to as soft tissue swelling, although it may involve the bone to some degree as well. In most instances the inflammation is a result of an injury to the face but the inflammation can also arise with infections and allergies. Less commonly there may be one sided swelling of the face due to abnormal tissue growth like a tumor which may either benign (non-cancerous) or malignant (cancerous)

When there is one sided facial swelling, it simply means that the tissue on the enlarged side is affected. Apart from the tissue, each side of its face has its own blood, nerve and lymphatic supply. Therefore a condition that affects these structures on one side will lead to swelling only on that side. If the condition is systemic, or  generalized, then both sides may be swollen simultaneously.

Causes of One Sided Facial Swelling

It is important to consider several factors when evaluating the cause of facial swelling which may provide a better indication of the cause.

1. Did the facial swelling start suddenly or develop gradually?

2. Is the affected side painful, tender, numb or experiencing other abnormal sensations?

3. Is the enlarged side hard, soft, spongy or firm?

4. Is the one sides facial swelling affecting speech, breathing, eating or chewing, sense of taste or smell, size of the eyes or eyelid movement?

5. Is the facial swelling isolated to the cheek or extending upwards to the forehead or downwards to the neck?


The most common cause for facial swelling that tends to occur very rapidly and is usually just temporary is an injury to face. In these cases, the cause can be identified to a specific incident. Trauma to the face may occur with :

  • Blow to the face, like during an assault.
  • Car accidents
  • Falls
  • Following dental surgery or other surgical procedures to the face.
  • Insect bites and stings
  • Chemical burns
  • Severe sunburn on one side
  • Fractures to the cranium or jaw

The enlargement in these cases is due to fluid accumulation as a result of inflammation. It is the body’s ways of protecting tissue against injury. The blood vessels become leaky allowing excess amounts of fluid from the bloodstream to enter into the tissue spaces. Usually there is also heat of the area, redness, tenderness or pain. If a blood vessel is ruptured due to trauma, there may be an accumulation of blood in the tissue. This is known as a hematoma.


A number of microorganisms can cause an infection on one side of the face. This may be isolated to the superficial layers like the skin and subcutaneous fat, or involve deeper tissue such as the muscle and even extend into the bone. It may be caused by viruses or bacteria which are the most common pathogens, or fungi and other types of parasites. The different types of infections that may cause one sided swelling of the face includes :

  • Cellulitis. If this extends to the area around the eye then it is known as orbital cellulitis.
  • Abscess – tooth, gingival (gum), peritonsillar.
  • Sinusitis which is an infection of the paranasal sinuses.
  • Osteomyelitis which is an infection of the skull bone or jaw
  • Parotitis which is an inflammation of the parotid gland most commonly caused by an infection like mumps.
  • Lymphadenitis which is the inflammation of lymph nodes.
  • Eye and eyelid infections like conjunctivitis, keratitis, stye (hordeolum) and blepharitis. The swelling is usually over and around the eye but may extend onto the cheek and up to forehead in severe cases.


There are a number of allergic reactions that can cause one sided facial swelling. The most important and severe is anaphylaxis (anaphylactic reactions) which can be life threatening without immediate medical attention. It usually causes bilateral swelling (entire face swollen). Other allergic causes includes :

  • Allergic conjunctivitis
  • Allergic rhinitis (hay fever)
  • Drug allergies
  • Allergies to insect bites and stings
  • Allergies to various substances that may be used in facial creams, cosmetics, implants for cheek augmentation and sometimes dental materials.

Muscle Problems

The facial muscles, like the large masseter muscle, gives the cheeks definition and problems with these muscles can alter the shape and size of the face.

  • Atrophy (shrinking) of the muscle on one side as may be seen with partial or complete muscle paralysis (like in Bell’s palsy).
  • Hypertrophy (enlargement) of the muscle on one side with clenching on one side or chewing only on one side.

Sometimes facial spasms associated with certain nerve and muscle diseases can cause a facial distortion.


Tumors, either benign (non-cancerous) or malignant (canerous) may arise in any of the following tissues :

  • Muscle
  • Bone
  • Subcutaneous fat
  • Skin
  • Connective tissue
  • Lymph nodes or vessels

Less frequently, a tumor or the blood vessels or nerves may also be responsible for the one sided swelling.

Other causes

Most of the other causes a systemic, meaning that it affects the entire body or several systems of the body simultaneously. It is unlikely to cause one sided facial swelling but instead swelling of the entire face. Nevertheless it is worth considering these conditions as a possible cause of one sided facial swelling.

  • Cushing’s disease
  • Kidney failure
  • Heart failure
  • Liver failure
  • Serum sickness
  • Malnutrition
  • Obesity
  • Christina Reis

    My inner part of my mouth. cheek area. feels like the bone area not sure but its in the bottom left side in the crease almost of my jaw area is hard and swoolen. I get itchy on my cheek and sometimes a slight red rash that no one can even notice except me. Thoughts?

  • Hi Kelli. This could be an infection that is worsening and spreading. This is just one possibility and we cannot diagnose her here. It is advisable that she sees a doctor immediately as this sounds serious.

  • Kimi

    I just woke up to the right side of my face swollen, from just under my eye next to my nose down through the hollow of my cheek to under my ear and edge of my jaw. Hard tender lumps…swollen lymph glands? Some slight numbness… In the last week i have had a severe sinus allergy attack and then woke up to pain across my lower back just beliw my ribs… And now this… What is happening to me?!

  • disqus_NVzhSMHovD

    Hi my swelling of the right side of my face gradually developed through the years. Its uncomfortable and some days its more swollen then other days…also the right side of my throat/neck is swollen as well. It feels like there’s something in my throat with never ending phlegm. What could this be?Iv been avoiding seeing a doctor because I’m scared.please help.

  • dedeotaku

    4 months ago i felt the right side of my face i swollen and i feel like it getting more noticeable these days .it does not hurt or anything but it just affect the way i look 🙁 ……HELP????

  • Pat DeVoy

    Hi Everyone,
    Over the last two weeks the left side of my face (next to my nose) has swollen from the edge of my mouth to my eye, my doctor told me to give up salt and if it isn’t gone in two weeks he will refer me to an ENT. If salt was the case why only one side is swelling. Any suggestions? Could it be an allergy?

  • Aquib

    Hi, when I woke up in the morning my left side of the face got swollen especially near my cheeks,there is no pain in that region,sometimes I have light head ache. I will be indebted to you

  • Hi Aquib. As you can see from the article above there are many possible causes of facial swelling on one side. One possibility is that you were clenching your teeth at night while sleeping. However, there are other conditions that could cause this and the only way to know the exact cause is to have it assessed by your doctor.

  • Elaheh Marand

    this morning when I woke up the right side of my face was swollen, mainly cheek and eye. last night before I went to sleep the right side of my tooth was sore, so that might be a source to the problem. what should I do? what will happen?

  • ReceMae

    About 3 weeks ago, I woke up and the inside of my right cheek was swollen, (visibly swollen) on the cheek and art of my gums. The swell is hard and I chew mainly on my right side, I think I might have hypertrophy. Is it an infection? I don’t have the money to see a doctor, what should I do to make the swelling go down ASAP? Please help.

  • Shahzeen

    Hi my 4 years old son face is swell one sided from yesterday . First it was only his uper lip but now his half face is swell what should i do ?

  • I taught swimming today from 10:00 to 11:00 and then I went to run an errand. When I got home, the left side of the back of my cheek around my jaw line near my ear was really swollen and shows a visible hard mass (about 2″ x 1″).

    While in the water, it felt like something flew in my ear. The mass doesn’t really hurt, but looks very odd. It only hurts a little if I maneuver my jawline. My teeth are fine. As of this writing, it is now 2:15 pm and the lump/mass is there. There is no red mark, just the swelling. Any thoughts about what it could be? I’ve never had anything like this. It is pretty strange.

  • EightBitGhost

    There is a hard lump about 3/4 of an inch below my eye to the right side of my nose that is very tender and it also has been affecting my right eye where it’s irritated and gets gunky. I have had many eye infections before and it doesn’t seem to be one any ideas as to what’s happening?

  • Mrunal Patel

    My right side of face is bigger than my left side….especially cheek area…is there any facial exercise which can reduce my one side of facial fat?

  • Hi Mrunal. It is important to first understand why there is this difference. Both sides of the face are not symmetrical but usually one side is not significantly larger than the other. If it just started up then it could be swelling due to some problem which needs to be treated. If it has been around for a long period of time then it could be due to an enlargement of the masseter muscle rather than fat. Follow up with your doctor and/or dentist to confirm the underlying cause and then he/she could advise you further on possible treatments.

  • PrestonAOL

    My left side of my face tends to swell at night, my cheeks and under my eye are affected and when this occurs I get twitches or spasms under the eye and a slight drowsy feel on my left side. Is it a health issue?

  • diba bahar

    I encounter swollen cheek since 4 years ago. It is not painful but it affects me psychologically. I’ve seen the doctor, they said it might be because previously i always chew only one side and the muscle getting bigger. Beside that, I also undergone a painful dental treatment before when i was a kid. Do you have any tips to reduce the swollen? I’m already clueless on what should i do. please do help me.

  • Hi Dida. The focus needs to be on what exactly is causing this enlargement of the cheek. Swelling means that there is fluid accumulation but this is usually not a common cause of an enlarged cheek that persists for so long. One of the more likely cause is an abnormal enlargment of the cheek muscles only on one side. The dental treatment in childhood is unlikely to be causing continued enlargement. More important is whether you have a tendency to clench. As you can see from the article above, there are various other causes. You should follow up with your doctor and possibly also consult with a specialist like a maxillofacial specialist. Your doctor will advise you further.

  • Luke Bannister

    Hi i have a small but very sore lump on my right cheek and my eye area has also swelled up and it is all very red and sore, could you please help?

  • Hi Luke. There are a number of different conditionsthat could cause the symptoms you are experiencing. It is unclear whether the lump on your cheek is related to the swelling on the eye. This could be related to an infection but there is no way of saying for sure through an online platform. Hopefully you have seen a doctor by now and started with the relevant treatment that was prescribed. If not speak to your faimly doctor.

  • Toni

    I was googling my symptoms and found site. I have problems with the left side of my face swelling along with the left side of my neck being swollen and tight. I do clench my teeth in my sleep and through the day. My dr. Said it’s probably TMJ. I did have my wisdom teeth pulled in March. I also see a dermatologist because I still have a cyst under my eye he gave me medication said if it gets infected he would give me a cortisone shot. So I’m just confused where to turn. It affects my eye it’s either very dry or watery.

  • Hi Toni. As you mention, there are quite a few factors that may have played a role in this swelling. Each condition needs to be appropriately treated and managed. Ultimately the swelling is a symptom of one or more of these conditions and when each condition has resolved then the swelling should subside. However, as you also mention you do clench your teeth which can also lead to abnormal enlargement of the masseter muscle. In the long term this will cause the one sided facial swelling to persist. You may want to start with your dentist or a maxillofacial specialist.

  • Pretty Smile

    My left cheek is swollen from last 4 years. The reason I was told was because I was not chewing from my left side.My wisdom teeth gone bad on that side thats why i was not able to chew at all on left side. It is not painful but one side looks all swelled up and my whole face alignment looks weird because of that. Kindly suggest.

  • sarath

    hi.. there is a swelling on my brother’s right cheek …. he experiences no pain.. but I’m concerned.. any suggestions on what this may be a symptom of?

  • Hi Pretty. It is possible that chewing only on one side can affect the size of the face between both sides. Muscle enlargement and shrinking can cause this alteration although other factors may also be involved. It is advisable to follow up with your doctor and dentist, and if necessary consult with a specialist like a maxillofacial specialist. If indeed the chewing is the problem then simple changes in chewing habits can make a difference but this will not occur overnight. Speak to your doctor.

  • Hi Sarath. Swelling of one cheek can occur for various different reasons as you can see from the article above. The lack of pain may mean that it is not due to inflammation but this is not always the case. It could instead be due to enlargement of the facial muscles on one side but this usually does not occur overnight. It is advisable that your brother follows up with his doctor and/or dentist as further investigation will be necessary to diagnose the underlying cause.

  • happygirl

    hi there my boyfriend recently woke up with half his face swollen and he’s sure that he has not eaten anything he’d be allergic to or injured his face, although he does have severe acne which could we think play a part in it but we are unsure.

  • Happy-go-lucky

    Last year, the left side of my face swelled. After it has decreased it size, the face became asymmetrical. I have eczema, a type of skin condition, so I’m not sure whether that is the cause. Even till now, my face hasn’t gine back to its original shape. My smile is slanted now!
    What can I do?

  • Julia Cummins

    One side of my face is larger than the other. This had been for a few months now. No problems…just swelling.

  • Hi Tinaya. Occasional swelling like what you are describing is uncommon. It could be related to an allergy or it may be angioedema although you don’t mention any other symptoms. The only way to know for sure is for him to see a doctor when this occurs. Then the exact cause can be identified and treated accordingly.


    mom is 71 had a stroke 3 months ago shes been sleeping on her left side and today woke up with her eye almost swollen shut should i worry

  • Hi Rosemary. Without knowing the exact cause of this swelling, it is difficult to say whether it needs emergency medical attention. By now you should have seen a doctor. As you can see from the article above, there are many possible causes of one sided swelling. It could be a dental infection on that side, enlargement of the cheek muscle or even a heart problem that is causing fluid to accumulate in the face when lying flat. If this is recurring or persisting and you have not sought medical attention yet, then please speak to a doctor as soon as possible.

  • Hi RFrankie. Lying for long periods on one side can cause swelling. The question here is whether this is due to your Mom’s prolonged bed rest or whether there is some other cause. Her age and history of a stroke could also mean that she has other cardiovascular conditions which may also be causing fluid to accumulate. It could also be due to a dental infection or some other cause. Speak to her doctor for further advice.

  • Ricardo

    Right cheek by my jaw has been swollen for about a week or so looks worse In morning. Went to a Dr they did blood work and seen nothing wrong there. There is no pain other than it is annoying to look at. Any idea? Also I am prepping for a bodybuilding competitiin nd my calories are pretty limited at about 1300 I exercise everyday and do swimming for cardio (swollenness was there prior to swimming)

  • Hi Ricardo. As you mentioned, the swelling/enlargement was there prior and probably the loss of body fat may just have made it more obvious. It could be enlargement of the cheek muscles on one side, which is more likely to occur with clenching or chewing more on one side. However, there are many other possible causes as you can see from above. If your doctor has not found any possible cause then maybe follow up with a dentist.