Why Is My Eye Swollen? Common Causes and How to Reduce the Swelling Quickly

Why is my eye swollen? Quick triage to narrow the cause

When your eye is swollen, the first step is figuring out what's likely going on. A few quick questions can help narrow things down fast.

One eye or both? If both eyes are swollen, think allergies or a systemic issue. If it's just one eye, it's more likely an infection, injury, or localized irritation.

Upper lid, lower lid, or both? Upper lid swelling often points to allergies or styes. Lower lid swelling can signal blocked glands or allergies. Swelling in both lids might indicate a more significant infection or inflammation.

Itchy, painful, or just pressure? Itching screams allergies or irritation. Pain suggests infection, injury, or inflammation. Pressure without much pain might be fluid retention or a blocked gland.

Discharge or crusting? Yellow or green discharge that crusts overnight points to bacterial infection. Watery tearing suggests allergies or viral infection. Dryness might indicate irritation or blepharitis.

Recent exposures or triggers? New makeup, face wash, or skincare products? Contact lenses? Pollen season? Recent illness? These clues can point you toward the likely culprit.

“Most swollen eyes are straightforward once you know what to look for,” says Chris Sales, MD, a board-certified physician. “The pattern of symptoms—where the swelling is, whether it's itchy or painful, what kind of discharge you have—these details help narrow down the cause quickly.”

Swollen eyelid causes: the most common culprits

Swollen eyes have a surprisingly short list of usual suspects. Here's what's most likely behind the puffiness:

Allergies

Allergic reactions are one of the top causes of swollen eyes. When your body encounters an allergen—like pollen, pet dander, dust mites, or certain cosmetics—it releases histamine, which causes blood vessels to dilate and leak fluid. This leads to swelling, redness, itching, and watery eyes. Allergic eye swelling usually affects both eyes and comes with intense itching.

Irritants

Non-allergic irritants can also cause swelling. Smoke, chlorine from pools, wind, or harsh chemicals can inflame the delicate skin around your eyes. Unlike allergies, irritation often causes more burning than itching and may affect one or both eyes depending on exposure.

Blocked oil glands (stye or chalazion)

Your eyelids have tiny oil glands that keep your eyes lubricated. When these glands get blocked, they can swell and form a stye (a painful, red bump) or a chalazion (a larger, less painful lump). Styes are usually tender and appear at the edge of the lid, while chalazia are deeper and less painful.

Blepharitis

Blepharitis is chronic inflammation of the eyelid edges, often caused by bacteria or skin conditions like dandruff. It can cause swollen, red, crusty eyelids that feel gritty or burning. Flare-ups can make swelling worse temporarily.

Conjunctivitis (pink eye)

Conjunctivitis inflames the clear membrane covering your eye and inner eyelids. Viral conjunctivitis causes watery discharge and often starts in one eye before spreading. Bacterial conjunctivitis produces yellow or green discharge and can make eyes stick shut. Allergic conjunctivitis causes itching, redness, and watery eyes in both eyes.

Fluid retention and lifestyle factors

Sometimes swollen eyes aren't about infection or irritation at all. Fluid retention from high salt intake, hormonal changes, lack of sleep, or crying can cause temporary puffiness. This type of swelling usually affects both eyes and tends to be worse in the morning.

Eyelid dermatitis: when skin irritation is the problem

Eyelid dermatitis happens when the delicate skin around your eyes gets irritated or inflamed. The skin here is thinner and more sensitive than elsewhere, so it reacts easily to things that wouldn't bother other areas.

Symptoms include redness, puffiness, itching, and dry or flaky skin. The swelling can range from mild puffiness to significant inflammation that makes it hard to open your eyes fully.

Common triggers include:

• Makeup products (especially eye shadow, mascara, or eyeliner)
• Face wash or cleansers that get near the eyes
• Nail polish (touching your eyes after polishing nails)
• Topical medications applied near the eyes
• Fragrances or preservatives in skincare products

If you suspect eyelid dermatitis, stop using any new products immediately. Gently cleanse the area with cool water and avoid rubbing. Use a gentle, fragrance-free moisturizer if the skin feels dry. Most cases improve within a few days once the irritant is removed.

If symptoms don't improve after a few days, or if you develop severe swelling, pain, or vision changes, seek care. A healthcare provider can help identify the trigger and may prescribe a mild topical steroid or other treatment to calm the inflammation.

Infections and inflammation that need closer attention

While many swollen eyes are mild and self-limiting, some infections and inflammatory conditions need medical attention to prevent complications.

Viral conjunctivitis

Viral conjunctivitis often starts with watery discharge, a gritty feeling, and redness. It's highly contagious and can spread easily through contact. The swelling is usually mild to moderate, and symptoms often start in one eye before moving to the other. Most cases clear up on their own within a week or two, but keeping hands clean and avoiding touching your eyes helps prevent spread.

Bacterial conjunctivitis

Bacterial infections cause yellow or green discharge that can crust and make your eyes stick shut, especially in the morning. Swelling can be more pronounced, and the eye often looks red and irritated. Unlike viral conjunctivitis, bacterial infections usually need antibiotic eye drops or ointment to clear up properly.

Blepharitis flares

Chronic blepharitis can flare up, causing increased swelling, redness, and crusting along the eyelid edges. These flares often respond to warm compresses and gentle eyelid hygiene, but persistent or severe cases may need prescription treatment.

Preseptal cellulitis

Preseptal cellulitis is a bacterial infection of the eyelid and surrounding skin. It causes significant swelling, redness, warmth, and tenderness. While it's usually treatable with oral antibiotics, it needs prompt medical attention to prevent it from spreading deeper.

Orbital cellulitis

Orbital cellulitis is rare but serious—it's an infection of the tissues behind the eye. Warning signs include fever, severe pain, bulging eye, vision changes, difficulty moving the eye, and double vision. This is a medical emergency that requires immediate care, as it can lead to vision loss or spread to the brain if untreated.

Injury, contact lenses, and foreign body irritation

Physical trauma and foreign objects can cause significant eye swelling, and how you respond depends on what happened.

Minor bumps and injuries

A minor bump or injury to the eye area can cause swelling and bruising (a black eye). Cold compresses help reduce swelling in the first 24–48 hours. If vision is affected, there's severe pain, or the eye itself (not just the lid) looks injured, get checked right away.

Foreign body irritation

Something in your eye—like dust, an eyelash, or a small particle—can cause swelling, redness, and tearing as your eye tries to flush it out. Try flushing with clean water or saline. If you can see the object and it's easy to remove, you can try gently, but don't dig or rub aggressively. If it won't come out or symptoms worsen, seek care.

Contact lens issues

Wearing contacts too long, sleeping in them, or using dirty lenses can cause swelling, redness, and irritation. Remove contacts immediately if your eye is swollen or painful. Give your eyes a break from lenses and see a provider if symptoms don't improve quickly—contact lens-related infections can be serious.

Chemical exposure

If a chemical gets in your eye, flush immediately with clean water for at least 15–20 minutes while seeking emergency care. Don't rub the eye, and don't delay flushing to call for help—have someone else call while you flush. Chemical burns can cause severe damage quickly.

Diagnosis and testing: what a clinician will check

When you see a healthcare provider for a swollen eye, they'll ask specific questions and do a focused exam to figure out what's going on.

They'll likely ask about:

• When the swelling started and how it's changed
• Whether it's one eye or both
• Any pain, itching, or other symptoms
• Discharge type and amount
• Recent exposures (new products, contacts, injuries, illness)
• Vision changes
• Any fever or other systemic symptoms

During the exam, they'll check your vision, look at the eye and eyelid appearance, check eye movement, examine the inside of your eyelids, and assess for signs of infection or inflammation. They may use a special light to look at your eye structures more closely.

In many cases, a provider can diagnose the cause based on symptoms and exam alone. If there's discharge, they might swab it to test for bacteria. If they suspect a more serious infection, they may order imaging or blood tests.

Virtual care with Gen Med is a great option for many swollen eye concerns. You can share photos of your eye, describe your symptoms, and get guidance on next steps—including whether you need in-person care or can manage things at home.

Treatment options: What is the fastest way to heal a swollen eyelid?

The fastest way to heal a swollen eyelid depends on what's causing it. Here's how to match the treatment to the cause:

Cold compresses

For allergic reactions, injuries, or general inflammation, cold compresses can reduce swelling quickly. Apply a cold, clean cloth or ice pack wrapped in a towel to the closed eye for 10–15 minutes several times a day. Don't apply ice directly to the skin.

Warm compresses

For styes, chalazia, or blepharitis, warm compresses help open blocked glands and improve drainage. Use a warm, clean cloth and apply for 10–15 minutes, 3–4 times daily. Make sure the compress isn't too hot to avoid burning delicate eyelid skin.

Eyelid hygiene

For blepharitis or styes, gentle eyelid hygiene helps. Use a warm, damp cloth or special eyelid wipes to clean along the lash line, removing any crust or debris. This can prevent flare-ups and help existing issues heal faster.

Eye drops

Over-the-counter antihistamine eye drops can help with allergic swelling and itching. Artificial tears can soothe irritation and flush out allergens. For bacterial infections, prescription antibiotic drops or ointments are usually needed.

Allergy treatment

If allergies are the culprit, oral antihistamines can help reduce systemic allergic reactions. Avoiding the allergen is key—if it's pollen, keep windows closed and use air filters. If it's a product, stop using it immediately.

Skin-calming care

For eyelid dermatitis, stop using any irritating products and use gentle, fragrance-free cleansers and moisturizers. A healthcare provider may recommend a mild topical steroid for severe cases, but these should be used carefully around the eyes and only under medical guidance.

Eye rest

Giving your eyes a break from screens, contacts, and makeup can help reduce irritation and allow healing. If you wear contacts, switch to glasses until symptoms resolve.

Prescription treatment

For bacterial infections, severe allergies, or persistent inflammation, prescription medications may be necessary. Antibiotic drops or ointments treat bacterial infections. Steroid eye drops can reduce severe inflammation, but they need careful monitoring. Oral antibiotics may be needed for more serious infections like preseptal cellulitis.

Most swollen eyes start improving within 24–48 hours of starting the right treatment. If symptoms don't improve or get worse, follow up with your provider.

What not to do (common mistakes that make swelling worse)

When your eye is swollen, it's tempting to try anything for relief. But some common mistakes can make things worse or delay healing:

• Don't squeeze a stye. Squeezing can push infection deeper and make it worse. Let it drain naturally or get medical help if needed.
• Don't use old medications. Expired eye drops or leftover prescriptions from previous issues may not be appropriate and could cause problems.
• Don't test new products. If your eye is already irritated, adding new makeup, creams, or treatments can make things worse.
• Don't wear contacts or makeup. Both can trap bacteria, add irritation, and prevent proper healing. Give your eyes a break until symptoms clear.
• Don't rub aggressively. Rubbing can introduce more bacteria, worsen irritation, and potentially scratch the cornea. If something's in your eye, flush with water instead.
• Don't ignore pain or vision changes. These can signal a more serious problem that needs prompt medical attention.

When in doubt, gentle care and avoiding potential irritants is usually the safest approach until you can get professional guidance.

When to seek care: red flags for a swollen eye

Most swollen eyes improve with simple care, but some symptoms signal you need medical attention right away:

• Vision changes: Blurry vision, double vision, or any vision loss needs immediate evaluation.
• Severe pain: Intense eye pain, especially if it's getting worse, warrants prompt care.
• Pain with eye movement: If it hurts to move your eye, this can indicate a deeper infection.
• Bulging eye: If your eye is pushing forward or bulging, this is a red flag for orbital cellulitis.
• Fever or spreading swelling: Fever with eye swelling suggests infection. Swelling that spreads beyond the eye area also needs attention.
• Light sensitivity: Severe sensitivity to light can indicate inflammation or infection that needs treatment.
• Chemical exposure: Any chemical in the eye needs immediate flushing and emergency care.
• Contact lens + pain: If you wear contacts and develop eye pain or swelling, remove lenses immediately and seek care—contact lens infections can be serious.

Working with a healthcare provider

Many swollen eye concerns can be addressed through virtual care with Gen Med. Virtual visits are convenient and often just as effective as in-person care for many eye issues.

To make the most of your visit, share clear photos of your eye from different angles. Good lighting helps—take photos in natural light if possible. Describe your symptoms clearly: when they started, what makes them better or worse, and any other symptoms you've noticed.

Track your symptoms before the visit: note when swelling started, whether it's getting better or worse, any discharge type and amount, and any treatments you've already tried. This information helps your provider make the right diagnosis and treatment plan.

Your Gen Med provider can assess your symptoms, recommend treatments, prescribe medications if needed, and determine whether you need in-person care or can manage things at home. They can also help identify triggers and suggest prevention strategies to reduce future episodes.

Prevention: Reduce the chances of recurring eyelid swelling

Once you know what caused your swollen eye, you can take steps to prevent it from happening again:

Allergy prevention

If allergies are the culprit, identify and avoid triggers when possible. During pollen season, keep windows closed, use air filters, and shower after being outdoors. Consider over-the-counter antihistamines preventively if you know you're entering a high-allergy period.

Contact lens hygiene

Follow proper contact lens care: wash hands before handling lenses, clean and store them properly, don't sleep in them (unless they're approved for extended wear), and replace them on schedule. Never use tap water or saliva to clean lenses.

Makeup hygiene

Replace eye makeup regularly (mascara every 3 months, eye shadow and liner every 6–12 months), don't share eye makeup, and remove makeup before bed. If you develop irritation, consider switching to hypoallergenic or fragrance-free products.

Blepharitis prevention

If you have chronic blepharitis, daily eyelid hygiene can prevent flares. Use warm compresses and gentle cleaning along the lash line. Managing underlying conditions like dandruff or rosacea can also help.

Dermatitis prevention

Patch test new products before using them near your eyes. Avoid products with fragrances, harsh chemicals, or known irritants. If you develop sensitivity to a product, stop using it immediately and avoid similar products in the future.

General eye health habits also help: protect your eyes from injury with safety glasses when needed, avoid rubbing your eyes, and give your eyes regular breaks from screens and contacts.

Key takeaways

• Most swollen eyes are caused by allergies, irritation, blocked glands, or mild infections and improve with simple at-home care.
• Quick triage questions—one eye vs both, itchy vs painful, type of discharge—can help narrow down the likely cause.
• Match treatment to the cause: cold compresses for allergies/injuries, warm compresses for styes/blepharitis, and prescription medications for infections.
• Red flags like vision changes, severe pain, bulging eye, or fever need immediate medical attention.
• Prevention strategies—proper contact lens care, makeup hygiene, avoiding allergens—can reduce the risk of recurring episodes.

Frequently asked questions (FAQs)

How do you treat a swollen eye?

Treatment depends on the cause. For allergies, try cold compresses and antihistamine eye drops. For styes or blepharitis, use warm compresses and gentle eyelid hygiene. For bacterial infections, you'll likely need prescription antibiotic drops or ointment. If you're not sure what's causing it, see a healthcare provider for proper diagnosis and treatment.

When should I worry about eye swelling?

Seek immediate care if you have vision changes, severe pain, pain with eye movement, bulging eye, fever, or spreading swelling. These can indicate serious infections like orbital cellulitis that need urgent treatment. If symptoms don't improve after a few days of home care, or if they're getting worse, it's also time to see a provider.

Why do I suddenly have a swollen eyelid?

Sudden eyelid swelling can happen for many reasons. Common causes include allergic reactions (to pollen, products, or other triggers), new makeup or skincare products, contact lens irritation, a stye or blocked gland, or an infection like conjunctivitis. If it came on quickly and you can't identify a clear cause, consider whether you've used any new products, been exposed to allergens, or had any eye contact recently.

How long do swollen eyes last?

It depends on the cause. Allergic reactions often improve within hours to a day once the trigger is removed. Styes typically resolve in a few days to a week with warm compresses. Infections may take several days to a week or more, depending on treatment. If swelling persists beyond a few days or gets worse, see a healthcare provider.

What can cause just one eye to swell?

One-eye swelling often points to localized issues like a stye, chalazion, injury, foreign body, contact lens problem, or infection (especially bacterial conjunctivitis, which often starts in one eye). Allergies can sometimes affect one eye more than the other, but they typically involve both eyes. If only one eye is swollen and you can't identify a clear cause, or if there's pain or vision changes, get it checked.