What is Conjunctivitis?


Conjunctivitis is the medical name for inflammation of the conjunctiva; this is the thin layer of tissue on the inside of the eyelids and which also covers the white part of the eye. Commonly known as pink eye, conjunctivitis is often caused by a virus (see viral conjunctivitis), bacteria (see bacterial conjunctivitis), allergies (see allergic conjunctivitis), or other non-infectious causes. Conjunctivitis is a common eye condition and is not usually serious.[1][2][3][4][5][6]

Good to know: Pink eye and styes are often confused. A stye or sty is a small, red, painful bump on the edge of the eyelid, which develops when an oil gland becomes infected with bacteria. It may resemble a pimple or boil.[7][8]

General symptoms of conjunctivitis include:[1][2][3][4][5][6]

  • Pinkness or redness of the eye, hence the name “pink eye”
  • Burning, itching, a sensation of grittiness, or mild pain or discomfort in the eye
  • Discharge from the eye; this may be watery or thick and pus-like, depending on the cause
  • Formation of a crust around the eye from discharge[9]
  • Swollen and/or reddened eyelids

Depending on the type of conjunctivitis, other signs and symptoms may be present. One or both eyes may be affected by conjunctivitis. When only one eye is affected, it is called unilateral conjunctivitis. When both eyes are affected, it is called bilateral conjunctivitis. If you think that you may have conjunctivitis.

Many cases of mild conjunctivitis clear up independently, without specific treatment. Home remedies and over-the-counter (OTC) treatments may be useful. Cleaning the eyes with water and a clean cloth or sterile pad, applying warm or cool compresses, and using lubricating eye drops, also known as artificial tears, may help to relieve symptoms. However, antibiotics, antiviral medication, or allergy medication may be necessary in more serious cases of conjunctivitis.[1][2][3][4][5][6]

Most people fully recover from conjunctivitis, and the condition does not typically cause any complications. However, in a small number of cases, pink eye can be severe and may cause damage to the eyes if it is not treated effectively.

Conjunctivitis can affect people of any age, though bacterial conjunctivitis tends to be more common among children than adults.[4] Bacterial and viral conjunctivitis is highly contagious, which means that the infection can spread quickly from one person to another. A person with infectious conjunctivitis must take steps to avoid passing it on to others, such as practicing good hygiene.

When to see a doctor for pink eye

Anyone with severe conjunctivitis symptoms should see a doctor immediately. These include:[4][6]

  • Intense pain in the eye
  • Extreme redness in the eye
  • Inability to open the eye
  • Severe sensitivity to light
  • Blurred vision that persists after wiping away discharge

If symptoms are mild but do not go away, medical advice should also be sought.

Furthermore, suppose conjunctivitis occurs in newborn babies or people with weakened immune systems, such as those who have HIV or are undergoing treatment for cancer. In that case, it can be very severe, and medical advice should be sought without delay.

Diagnosing conjunctivitis

If symptoms are mild, a diagnosis of conjunctivitis can generally be made without seeing a doctor. The condition can be managed at home with home remedies and OTC eye drops. However, seeing a doctor is very important if there is any uncertainty or concern over the condition or the symptoms seem severe.

A doctor will take the person’s medical history and examine their eyes to determine whether the pink eye is present and what type of conjunctivitis it is. They will rule out other eye conditions like dry eye syndrome and more serious concerns such as uveitis and keratitis, an inflammation of the cornea, the front part of the eye. In some cases, laboratory tests may be necessary to confirm the diagnosis.[1][3][5]

Types of conjunctivitis

There are three main types of conjunctivitis or pink eye:

Bacterial conjunctivitis

Bacterial conjunctivitis is a pink eye that is caused by infection with bacteria, e.g., Staphylococcus aureus and Streptococcus pneumonia, or, less commonly, the bacteria chlamydia (causing chlamydial conjunctivitis) and gonorrhea (causing gonococcal conjunctivitis), which are sexually transmitted infections (STIs). Read more about bacterial conjunctivitis, including specific symptoms, treatment approaches including antibiotics, possible complications, and prevention strategies.

Viral conjunctivitis

Viral conjunctivitis is a pink eye caused by infection with a virus, e.g., adenovirus – the group of viruses that cause the common cold, herpes simplex, or herpes zoster ophthalmicus. Read more about viral conjunctivitis, including specific symptoms, treatment options including antiviral medication, possible complications, and prevention strategies.

Non-infectious conjunctivitis

The third type of conjunctivitis is not caused by bacteria or viruses and is not infectious, meaning it cannot be spread from person to person. There are several different subtypes of non-infectious conjunctivitis. These include:

Allergic conjunctivitis

Allergic conjunctivitis is the most common subtype of non-infectious conjunctivitis/pink eye caused by an allergen, e.g., pollen, dust, or animal dander. Read more about allergic conjunctivitis, including specific symptoms, types including giant papillary conjunctivitis and vernal keratoconjunctivitis, treatment options, and possible complications.

Irritant conjunctivitis

Sometimes mistaken for an allergic reaction, this type of conjunctivitis can be caused by irritation from various substances. These include cosmetic products, soaps, swimming pool chlorine, and other commonly used chemicals, smoke, dirt, and other objects that may get into the eyes.[1][3][10][11][12]

If the eye suffers physical trauma, for example, by being hit or scraped, symptoms of conjunctivitis may also develop.[12] This can be very serious, and a doctor should be seen without delay to prevent complications.

Mild cases of irritant-related conjunctivitis can usually be treated by removing or avoiding the irritating substance, flushing the eyes with water, and applying compresses, and lubricating eye drops to the eyes. However, more serious cases may require specialist medical treatment.

If symptoms are severe, or the irritant is a toxic substance, e.g., a strong chemical, medical attention should be sought urgently.

Toxic conjunctivitis

This type of conjunctivitis is often mistaken for an allergic reaction and can be considered a subtype of irritant conjunctivitis. However, toxic conjunctivitis is caused by the use of certain eye care products or eye medications for an extended period of time. It most commonly occurs in people with glaucoma.

Toxic conjunctivitis tends to be commonly caused by preservatives in eye medication, contact lens solutions, and artificial tears.[13] A doctor can advise on the best treatment approach.

Conjunctivitis in newborn babies

Newborn babies can be affected by various types of pink eye, including viral conjunctivitis and bacterial conjunctivitis, as well as irritant-caused conjunctivitis. Regardless of the cause, pink eye in infants is called neonatal conjunctivitis or ophthalmia neonatorum.

Babies with conjunctivitis usually develop puffy, red eyelids and discharge from the eyes within 1-14 days of birth.[4][14]

During the childbirth process, an infant’s eyes may become infected with a virus or bacteria from the mother. In some cases, this may be the bacteria linked to chlamydia and gonorrhea or, rarely, the herpes simplex viruses that cause oral herpes and genital herpes.[14][15]

Silver nitrate solution, traditionally administered to a newborn’s eyes to prevent conjunctivitis, can cause irritant conjunctivitis. For this reason, many doctors now avoid using silver nitrate and use antibiotic eye drops instead. However, some babies may also develop irritant conjunctivitis from the chemicals in these eye drops.[14][16][17]

Sometimes, a case of conjunctivitis in a baby is confused with sticky eyes caused by a blocked tear duct. However, a blocked tear duct will not cause the redness or swelling seen in conjunctivitis.[4]

Conjunctivitis in babies can be extremely serious, and any infant showing signs of conjunctivitis should be taken to a doctor immediately. Treatment with antibiotic, antiviral or other medication may be necessary, together with referral to an ophthalmologist.[15]

Conjunctivitis treatment

In many cases, conjunctivitis in adults and children will clear up on its own, without specific treatment. To relieve discomfort, the following home remedies and over-the-counter medicines may be helpful:[1][3][4][18][19]

  • Gently wiping discharge from the eye with a clean cloth, sterile pad or cotton wool soaked in water
  • Applying lubricating eye drops, called artificial tears, which are available without a prescription, to the eye
  • Applying a cold or warm compress – a clean cloth that has been soaked in water – to the eye
  • Avoiding rubbing the eyes, as this may aggravate symptoms
  • Avoiding the use of contact lenses and makeup until the conjunctivitis has cleared
  • In the case of allergic conjunctivitis, avoiding exposure to the allergen, e.g. dust

In serious cases of conjunctivitis, prescription eye drops and other medicine, such as antihistamine tablets – for allergic conjunctivitis, antibiotics – for bacterial conjunctivitis, and antiviral medication – for viral conjunctivitis, may be recommended. Sometimes, a person will be referred to an eye specialist, an ophthalmologist, for treatment.

Good to know: Eye drops, including those used for the treatment of pink eye, have expiration dates set for a specific period after they are first opened. As the efficacy of the ingredients, including the preservatives, may be reduced after the expiry date and harmful bacteria may enter the container, it is important not to use eye drops after the expiration date. It is also important not to share eye drops with other people. Always follow the instructions provided with the eye drops regarding how to use them and how to store them properly, which may include keeping them in a cool, dry place or in the fridge.[20][21]

Conjunctivitis (Pink eye) FAQs

u003cstrongu003eAre conjunctivitis and pink eye the same thing?u003c/strongu003e

Yes. Conjunctivitis is the medical term for the common eye condition known colloquially as pink eye or pinkeye.

u003cstrongu003eIs conjunctivitis contagious?u003c/strongu003e

Whether conjunctivitis is contagious or not u003cstrongu003edepends on the cause.u003c/strongu003e u003ca href=u0022https://adoctor.org/conditions/bacterial-conjunctivitis/u0022u003eConjunctivitis caused by bacteriau003c/au003e or u003ca href=u0022https://adoctor.org/conditions/viral-conjunctivitis/u0022u003econjunctivitis caused by a virusu003c/au003e is highly contagious and can be spread easily from person to person. However, u003ca href=u0022https://adoctor.org/conditions/allergic-conjunctivitis/u0022u003epink eye caused by allergies or irritantsu003c/au003e is not contagious and cannot be transmitted to other people.

u003cstrongu003eIs conjunctivitis airborne?u003c/strongu003e

In some cases, it can be. For example, in the case of u003ca href=u0022https://adoctor.org/conditions/allergic-conjunctivitis/u0022u003eallergic conjunctivitisu003c/au003e, the condition can be caused by airborne allergens such as pollen. In the case of viral conjunctivitis, an infection may occur by coming into contact with airborne droplets released when an affected person coughs or sneezes. However, in many cases of infectious conjunctivitis, it is spread by hand-to-eye contact or direct contact with a contaminated object, for example, when other family members share towels or washcloths with an infected person.u003csupu003eu003ca href=u0022https://adoctor.org/wp-admin/post.php?post=4784u0026amp;action=edit#fn22u0022u003e[22]u003c/au003eu003c/supu003e

u003cstrongu003eCan conjunctivitis go away by itself?u003c/strongu003e

Yes. In many cases, pink eye is mild and will clear up on its own without any specific treatment. However, the condition can be severe in some cases and may require treatment with prescription medications. If you have any concerns about an eye condition, it is advisable to consult a doctor.

u003cstrongu003eCan pink eye cause a sore throat?u003c/strongu003e

The pink eye itself cannot cause a sore throat. However, pink eye and sore throat may be two symptoms caused by infection with a cold virus, a common cause of conjunctivitis. There may also be a runny nose and other signs of a u003ca href=u0022https://adoctor.org/conditions/common-cold/u0022u003ecommon coldu003c/au003e.u003csupu003eu003ca href=u0022https://adoctor.org/wp-admin/post.php?post=4784u0026amp;action=edit#fn23u0022u003e[23]u003c/au003eu003c/supu003e While uncommon, a person can also experience strep throat and pink eye simultaneously. The bacteria that cause strep throat can also cause conjunctivitis.u003csupu003eu003ca href=u0022https://adoctor.org/wp-admin/post.php?post=4784u0026amp;action=edit#fn24u0022u003e[24]u003c/au003eu003c/supu003e

u003cstrongu003eI have had conjunctivitis for several weeks. Do I need to see a doctor?u003c/strongu003e

How long pink eye lasts often depends on the cause: most mild, uncomplicated cases of u003ca href=u0022https://adoctor.org/conditions/viral-conjunctivitis/u0022u003eviral conjunctivitisu003c/au003e and u003ca href=u0022https://adoctor.org/conditions/bacterial-conjunctivitis/u0022u003ebacterial conjunctivitisu003c/au003e clear up within 1-2 weeks. If symptoms do not improve after a few days, or they get worse, or there is any confusion about what is causing eye symptoms, it is advisable to see a doctor as soon as possible. If antibiotic medicine has been prescribed for bacterial conjunctivitis and symptoms do not begin to improve after 24 hours, a doctor should also be seen.u003csupu003eu003ca href=u0022https://adoctor.org/wp-admin/post.php?post=4784u0026amp;action=edit#fn3u0022u003e[3]u003c/au003eu003ca href=u0022https://adoctor.org/wp-admin/post.php?post=4784u0026amp;action=edit#fn25u0022u003e[25]u003c/au003eu003c/supu003e If you are concerned about any non-severe symptoms, contact your doctor. u003ca href=u0022https://adoctor.org/u0022u003eFind My doctor’s locationu003c/au003e for a free assessment.

Associated terms used for conjunctivitis

  • Pink eye, or pinkeye
  • Eye infection or inflammation
  • Madras eye

  1. Southern Cross Medical Library. “Conjunctivitis (pink eye) – symptoms and treatment.” January, 2018. Accessed June 15, 2018.

  2. Association of Optometrists. “Bacterial and viral conjunctivitis.” Accessed June 15, 2018.

  3. National Eye Institute. “Facts About Pink Eye.” November, 2015. Accessed June 15, 2018.

  4. Patient (Consumer). “Infective Conjunctivitis.” February 24, 2017. Accessed June 15, 2018.

  5. Patient (Pro). “Conjunctivitis.” February 24, 2017. Accessed June 15, 2018.

  6. UpToDate. “Patient education: Conjunctivitis (pink eye) (Beyond the Basics).” August 19, 2016. Accessed June 15, 2018.

  7. Healthline. “The 8 Best Stye Remedies.” July 5, 2018. Accessed September 28, 2018.

  8. Mayo Clinic. “Sty – Symptoms & causes.” June 5, 2018. Accessed September 28, 2018.

  9. Amboss. “Conjunctivitis.” April 10, 2018. Accessed July 4, 2018.

  10. Patient (Consumer). “Allergic Conjunctivitis.” February 28, 2017. Accessed June 16, 2018.

  11. Centers for Disease Control and Prevention. “Conjunctivitis (Pink Eye): Causes.” October 2, 2017. Accessed June 16, 2018.

  12. DermNet NZ. “Irritant or traumatic conjunctivitis.” December, 2015. Accessed June 16, 2018.

  13. UpToDate. “Toxic conjunctivitis.” March 16, 2016. Accessed June 16, 2018.

  14. Centers for Disease Control and Prevention. “Conjunctivitis (Pink Eye) in Newborns.” October 2, 2017. Accessed June 15, 2018.

  15. Canadian Family Physician. “Treatment and prevention of ophthalmia neonatorum.” November, 2013. Accessed June 15, 2018.

  16. Medscape. “Neonatal Conjunctivitis (Ophthalmia Neonatorum).” April 18, 2017. Accessed July 5, 2018.

  17. Johns Hopkins Medicine. “Conjunctivitis in Children.” Accessed July 5, 2018.

  18. Patient (Pro). “Infective conjunctivitis.” February 24, 2017. Accessed June 16, 2018.

  19. Centers for Disease Control and Prevention. “Conjunctivitis (Pink Eye): Treatment.” October 2, 2017. Accessed June 16, 2018.

  20. UFS. “Why Do You Have To Discard Eye Drops After 28 Days?” Accessed September 30, 2018.

  21. American Academy of Ophthalmology. “Can you tell me the standard recommendation for the shelf-life of over-the-counter eye drops once opened?” March 10, 2014. Accessed September 30, 2018.

  22. Centers for Disease Control and Prevention. “Conjunctivitis (Pink Eye).” October 16, 2017. Accessed September 30, 2018.

  23. Rady Children’s Hospital San Diego. “Viruses Most Common Cause of Pinkeye.” Accessed October 1, 2018.

  24. Williamson Medical Center. “Strep throat is common in kids, but many parents have misconceptions.” September 25, 2017. Accessed October 1, 2018.

  25. Healthline. “How Long Does Pink Eye Last?” October 27, 2017. Accessed September 30, 2018.

**Q&A: Understanding Conjunctivitis**

**What is Conjunctivitis?**

Conjunctivitis, commonly ⁢known as pink eye, is an inflammation of the‌ conjunctiva, the transparent membrane that covers the white part of the eye and ‍lines the eyelid. It can occur in one or both eyes and causes symptoms such as redness, swelling,⁤ itching, and tearing.

**What Causes Conjunctivitis?**

* **Bacterial ⁢Conjunctivitis:** Caused by bacteria such as Staphylococcus aureus or ⁤Streptococcus pneumoniae.

* **Viral Conjunctivitis:** Caused by viruses⁣ like adenoviruses or herpes simplex virus.

* ​**Allergic Conjunctivitis:** Triggered⁢ by allergens such ‌as pollen, dust, or animal​ dander.

* **Irritant‍ Conjunctivitis:** Caused by irritants such as smoke, chemicals, ⁤or chlorine in pools.

**How Does Conjunctivitis Spread?**

* **Bacterial and Viral Conjunctivitis:** Highly contagious⁢ and can be spread through contact⁤ with contaminated hands, objects, or bodily fluids.

* **Allergic Conjunctivitis:** Not contagious but​ can be triggered by allergens in the environment.

* **Irritant Conjunctivitis:** Not contagious but can occur after exposure to irritants.

**Symptoms of Conjunctivitis**

* Redness of the eyes

* Swelling and ‍lumpiness of the eyelid

* Itching and burning sensations

* Tearing or discharge from the eyes

*​ Sensitivity to light

* Blurred vision in severe cases

**Treatment ​for Conjunctivitis**

* **Bacterial Conjunctivitis:** Treated​ with antibiotic eye drops ⁢or ointment.

* **Viral Conjunctivitis:** No specific treatment available; supportive care involves cold compresses, artificial tears, and over-the-counter pain relievers.

* **Allergic ⁤Conjunctivitis:** Antihistamine eye​ drops or oral medications to reduce inflammation and block allergens.

* **Irritant Conjunctivitis:** Removal of the irritant and use of artificial​ tears to soothe the eyes.

**Prevention of ⁤Conjunctivitis**

* Wash hands frequently, especially after being ‌in public or handling sick people.

* Avoid touching your eyes or using contaminated eye makeup.

* Do not share personal items such as towels or eyeglasses.

* ⁣Keep contact ‍lenses clean and replace them as directed.

* Remove contact lenses immediately if your eyes become red or irritated.

**When to Seek Medical Attention**

Seek medical attention if you experience:

* Severe pain or vision changes

* ​Discharge that is thick, yellow, or green

* Symptoms that do not improve within‌ a few days

* Repeated episodes of conjunctivitis

*​ Presence of corneal ulcers (small white bumps on the cornea)

**Additional Information**

* Conjunctivitis is a common eye condition that can affect people of all ages.

* It is important to determine the type of conjunctivitis to ​receive ‌appropriate treatment.

* Home remedies⁣ such as cold compresses and artificial tears can provide temporary relief.

* Conjunctivitis is usually not a serious condition, but it can cause discomfort and interfere with daily activities.


  1. Conjunctivitis, also known as pink eye, is a common eye infection that causes inflammation of the conjunctiva, the clear membrane that covers the white part of the eye and lines the eyelid.

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