Eye Swelling: Causes and When to Worry

What eye swelling looks like

"Eye swelling" usually means swelling of the eyelids and the soft tissue around the eye (periorbital tissue). The eyelid skin is the thinnest in the body and sits on loose tissue, so fluid collects there easily and can close an eye quickly. Swelling of the eye itself, such as a bulging eyeball, is less common and more concerning.

Causes by pattern

Common causes of a swollen eye

Allergies

Pollen, pet dander, dust mites, makeup and eye drops can cause itchy, watery, puffy eyelids, usually on both sides. Rubbing makes it worse. Allergic contact dermatitis from cosmetics, hair dye or nail polish causes dry, red, itchy eyelid skin.

Stye and chalazion

A stye is an infected oil gland or eyelash follicle that causes a painful red bump at the edge of the lid, sometimes with a yellow head. A chalazion is a blocked oil gland deeper in the lid that forms a firm, usually painless lump. Both can cause the whole lid to swell.

Insect bites

Bites near the eye can cause dramatic swelling, often worse the next morning, because the lid tissue is so loose. Itching rather than pain, and no fever, point to a bite.

Conjunctivitis

Pink eye causes redness, discharge, grittiness and mild lid swelling. Viral conjunctivitis often starts in one eye and spreads to the other. Bacterial conjunctivitis produces thicker, yellow-green discharge.

Blepharitis

Blepharitis is chronic inflammation of the lid margins, with crusting at the lashes, burning, and red, slightly swollen lids. It often recurs.

Fluid retention and lifestyle

Puffy eyes in the morning are common after crying, salty meals, alcohol, poor sleep or sleeping face-down. They usually settle within hours of getting up.

Injury

A blow to the eye causes swelling and bruising ("black eye"). It needs checking if vision is affected, there is blood in the front of the eye, double vision, or numbness of the cheek, which can signal an orbital fracture.

Serious causes

Periorbital and orbital cellulitis

Periorbital (preseptal) cellulitis is infection of the eyelid skin in front of the eye. It causes a red, swollen, tender lid, often after a bite, scratch, stye or sinus infection. It is more common in children and is treated with antibiotics.

Orbital cellulitis is infection behind the orbital septum, around the eye itself, usually spreading from the sinuses. It causes pain on moving the eye, a bulging eye, double vision, reduced vision and fever. It can threaten vision and spread to the brain, so it needs hospital treatment with IV antibiotics.

Angioedema and anaphylaxis

Sudden swelling of the eyelids and lips can come from food, medicine or sting allergy, or from ACE inhibitor blood pressure medicines. With breathing difficulty or throat tightness, it is an emergency.

Thyroid eye disease

Graves' disease can cause puffy lids, bulging eyes, a staring look, grittiness, redness and double vision. It can occur even when thyroid levels are normal.

Kidney and other systemic causes

Swelling of both eyes in the morning, especially in a child, can be the first sign of nephrotic syndrome, in which the kidneys leak protein. Foamy urine and swollen ankles are other clues.

How doctors assess eye swelling

A doctor will check vision, eye movements, pupils, the eyelids and the surface of the eye, and may use a slit lamp. They will ask about itching, pain, fever, injury, new products and medicines. Depending on the findings:

• a CT scan of the orbits and sinuses if orbital cellulitis or a fracture is suspected
• urine and blood tests if kidney disease is possible
• thyroid blood tests for thyroid eye disease
• allergy testing for recurrent allergic swelling

Swollen eye treatment

Home care

• Allergies and bites: cool compresses for 10 minutes several times a day, oral non-drowsy antihistamines, and antihistamine eye drops. Avoid rubbing.
• Stye or chalazion: warm compresses for 10 to 15 minutes, 3 to 4 times a day, followed by gentle lid massage. Do not squeeze.
• Blepharitis: daily warm compresses and lid cleaning with diluted baby shampoo or lid wipes.
• Morning puffiness: sleep with your head slightly raised, reduce salt and alcohol, and use a cool compress.
• Remove contact lenses until the swelling settles, and stop new eye makeup or skin products.

Medical treatment

• Bacterial conjunctivitis: antibiotic eye drops in some cases.
• Periorbital cellulitis: oral antibiotics, with close follow-up.
• Orbital cellulitis: hospital admission, IV antibiotics and sometimes surgery to drain an abscess.
• Chalazion that persists: steroid injection or a small drainage procedure.
• Angioedema: antihistamines and steroids, epinephrine for anaphylaxis, and stopping any trigger medicine.
• Thyroid eye disease: lubricating drops, selenium in mild cases, and specialist treatments for active disease.

Frequently asked questions

Why is only one eye swollen?

One-sided swelling is usually from a stye, chalazion, insect bite, conjunctivitis or injury. If the swollen eyelid is red, hot and tender with fever, it may be cellulitis. Pain moving the eye or vision changes need emergency care.

How do I get rid of a swollen eye fast?

For allergies or bites, use a cool compress and an oral antihistamine. For a stye, use warm compresses several times a day. Raise your head when sleeping and avoid rubbing. If swelling comes with pain, fever or vision changes, see a doctor.

When should I worry about a swollen eye?

Seek urgent care for pain on moving the eye, bulging, double or reduced vision, fever with a red, tender lid, swelling after injury, or swelling with breathing difficulty. These may mean orbital cellulitis, a fracture or a severe allergic reaction.

Can allergies cause eye swelling?

Yes. Allergies are one of the most common causes. They usually cause itchy, watery, puffy eyelids on both sides, often with sneezing or a runny nose. Antihistamine tablets or eye drops and cool compresses help.

How long does eye swelling last?

Swelling from an allergy or bite usually settles within 1 to 3 days. A stye typically resolves within 1 to 2 weeks. A chalazion can take weeks to months. Swelling that persists or worsens despite home care should be checked.