Involutional stenosis is probably the most common cause of NLD obstruction in older persons. It affects women twice as frequently as men. Although the inciting event in this process is unknown, clinicopathologic study suggests that compression of the lumen of the NLD is caused by inflammatory infiltrates and edema. This may be the result of an unidentified infection or possibly an autoimmune disease.

Sinus disease often occurs in conjunction with, and in other instances may contribute to the development of NLD obstruction. Patients should be asked about previous sinus surgery, as the NLD is sometimes damaged when the maxillary sinus ostium is being enlarged anteriorly.

About 60 percent of initial attacks of dacryocystitis will recur. Individuals with a poorly functioning immune system (immunocompromised) may develop orbital cellulitis, which may lead to optic neuritis, proptosis, motility abnormalities, or blindness.

A variety of causes may lead to dacrocystitis. Most notably, obstruction of the nasolacrimal duct leads to stasis of the nasolacrimal fluid, which predisposes to infection. Staphylococcus aureus is a common bacterial pathogen causing infectious dacrocystitis. Sometimes, especially in women, stones may develop in the lacrimal gland, causing recurrent bouts of dacrocystitis; this condition is called "acute dacryocystic retention syndrome."

Also due to pneumococcus, infection due to surrounding structure such as paranasal sinuses.

Timo cysts may spontaneously resolve or with pressure directed toward the nose; however, nasolacrimal duct probing may be required to open the obstruction.

The nasolacrimal ducts drain the excess tears from our eyes into the nasal cavity. In dacryocystocele there this tube gets blocked on either end and as a result when mucoid fluid collects in the intermediate patent section it forms a cystic structure.

Very few risk factors for choanal atresia have been identified. While causes are unknown, both genetic and environmental triggers are suspected. One study suggests that chemicals that act as endocrine disrupters may put an unborn infant at risk. A 2012 epidemiological study looked at atrazine, a commonly used herbicide in the U.S., and found that women who lived in counties in Texas with the highest levels of this chemical being used to treat agricultural crops were 80 times more likely to give birth to infants with choanal atresia or stenosis compared to women who lived in the counties with the lowest levels. Another epidemiological report in 2010 found even higher associations between increased incidents of choanal atresia and exposure to second-hand-smoke, coffee consumption, high maternal zinc and B-12 intake and exposure to anti-infective urinary tract medications.

The perforation may heal in a few weeks, or may take up to a few months. Some perforations require intervention. This may take the form of a paper patch to promote healing (a simple procedure by an ear, nose and throat specialist), or surgery (tympanoplasty). However, in some cases, the perforation can last several years and will be unable to heal naturally.

Hearing is usually recovered fully, but chronic infection over a long period may lead to permanent hearing loss. Those with more severe ruptures may need to wear an ear plug to prevent water contact with the ear drum.

An imperforate lacrimal punctum is a congenital disorder of dogs involving the lack of an opening to the nasolacrimal duct (tear duct) in the conjunctiva. Dogs normally have two lacrimal puncta, the superior and inferior. This condition can affect either or both. Symptoms include excessive tearing and tear staining of the hair around the eye. Affected breeds include the American Cocker Spaniel, Bedlington Terrier, Golden Retriever, Poodle, and Samoyed. Imperforate lacrimal puncta can be corrected by surgical opening of the punctum.

A perforated eardrum or punctured eardrum is a rupture or perforation (hole) of the eardrum which can occur as a result of otitis media (ear infection), trauma (e.g. by trying to clean the ear with sharp instruments), explosion, loud noise or surgery (accidental creation of a rupture). Flying with a severe cold can also cause perforation due to changes in air pressure and blocked eustachian tubes resulting from the cold. This is especially true on landing.

Two percent of women will have a Bartholin's gland cyst at some point in their lives. They occur at a rate of 0.55 per 1000 person-years and in women aged 35–50 years at a rate of 1.21 per 1000 person-years. The incidence of Bartholin duct cysts increases with age until menopause, and decreases thereafter. Hispanic women may be more often affected than white women and black women. The risk of developing a Bartholin's gland cyst increases with the number of childbirths.

While Bartholin cysts can be quite painful, they are not life-threatening. New cysts cannot absolutely be prevented from forming, but surgical or laser removal of a cyst makes it less likely that a new one will form at the same site. Those with a cyst are more likely than those without a cyst to get one in the future. They can recur every few years or more frequently. Many women who have marsupialization done find that the recurrences may slow, but do not actually stop.

Causes of epiphora are any that cause either overproduction of tears or decreased drainage of tears, resulting in tearing onto the cheek. This can be due to ocular irritation and inflammation (including trichiasis and entropion) or an obstructed tear outflow tract which is divided according to its anatomical location (i.e. ectropion, punctal, canalicular or nasolacrimal duct obstruction). The latter is often due to aging (a spontaneous process), conjunctivochalasis, infection (i.e. dacryocystitis), rhinitis, and in neonates or infants, failure of the nasolacrimal duct to open. Another cause could be poor reconstruction of the nasolacrimal duct system after trauma to the area. Cause of trauma could be facial fractures (including nasoethmoid fractures or maxillary Le Fort fractures), and soft tissue trauma involving the nose and/or the eyelid.

This condition is often frustrating or irritating. A systematic review studying the usage of punctal plugs for treatment of dry eye reported a few cases of epiphora among participants.

Chalazion is a cyst in the eyelid due to a blocked oil gland. They are typically in the middle of the eyelid, red, and non painful. They tend to come on gradually over a few weeks.

A chalazion may occur following a stye or from hardened oils blocking the gland. The blocked gland is usually the meibomian gland but can also be the gland of Zeis. A stye and cellulitis may appear similar. A stye, however, is usually more sudden in onset, painful, and occurs at the edge of the eyelid. Cellulitis is also typically painful.

Treatment is typically initially with warm compresses. If this is not effective injecting steroids into the lesion may be tried. If large, incision and drainage may be recommended. While relatively common the frequency of the condition is unknown. The term is from the Greek "khalazion" meaning "small hailstone".

Epiphora is an overflow of tears onto the face. A clinical sign or condition that constitutes insufficient tear film drainage from the eyes in that tears will drain down the face rather than through the nasolacrimal system.

Most patients will fully recover from dacryoadenitis. For conditions with more serious causes, such as sarcoidosis, the prognosis is that of the underlying condition.

Atresia is a condition in which an orifice or passage in the body is (usually abnormally) closed or absent.

Examples of atresia include:

- Biliary atresia, a condition in newborns in which the common bile duct between the liver and the small intestine is blocked or absent.

- Choanal atresia, blockage of the back of the nasal passage, usually by abnormal bony or soft tissue.

- Esophageal atresia, which affects the alimentary tract and causes the esophagus to end before connecting normally to the stomach.

- Imperforate anus, malformation of the opening between the rectum and anus.

- Intestinal atresia, malformation of the intestine, usually resulting from a vascular accident in utero.

- Microtia, absence of the ear canal or failure of the canal to be tubular or fully formed (can be related to Microtia, a congenital deformity of the pinna, or outer ear).

- Ovarian follicle atresia, the degeneration and subsequent resorption of one or more immature ovarian follicles.

- Potter sequence, congenital decreased size of the kidney leading to absolutely no functionality of the kidney, usually related to a single kidney.

- Pulmonary atresia, malformation of the pulmonary valve in which the valve orifice fails to develop.

- Renal agenesis, only having one kidney.

- Tricuspid atresia, a form of congenital heart disease whereby there is a complete absence of the tricuspid valve, and consequently an absence of the right atrioventricular connection.

- Vaginal atresia, a congenital occlusion of the vagina or subsequent adhesion of the walls of the vagina, resulting in its occlusion.

Temporary alleviation can be achieved by inserting an oral airway into the mouth. However, the only definitive treatment is surgery to correct the defect by perforating the atresia to create a nasopharyngeal airway. If the blockage is caused by bone, this is drilled through and stent inserted. The patient has to have this sucked out by an air vacuum machine . And in later life as a teenager or in early twenties the hole will have to be re-drilled larger.

A stent may be inserted to keep the newly formed airway patent or repeated dilatation may be performed.

A chalazion or meibomian cyst can sometimes be mistaken for a stye.

Salivary gland aplasia (also termed salivary gland agenesis) is the congenital absence of salivary glands. Usually the term relates to the absence of some or all of the major salivary glands.

It is a rare condition, and most known cases have been in association with syndromes of the ectodermal tissues, particularly the lacrimal apparatus. Example syndromes which have been reported with salivary gland aplasia include hereditary ectodermal dysplasia, mandibulofacial dysostosis and hemifacial microsomia.

The main significance of the condition is a lack of saliva, causing xerostomia (dry mouth), with accompanying susceptibility to dental caries (tooth decay), infections of the mouth, and upper respiratory tract infections (e.g., candidiasis, ascending sialadenitis, laryngitis and pharyngitis). Patients with salivary gland aplasia typically require regular application of topical fluoride to prevent tooth decay.

Mumps can be prevented by immunization. Gonococcus, bacteria can be avoided by the use of condoms. Most other causes cannot be prevented.

"Dehydration:"

This is a common, non-infectious cause of parotitis. It may occur in elderly or after surgery.

"Acute bacterial parotitis:"

is most often caused by a bacterial infection of Staphylococcus aureus but may be caused by any commensal bacteria.

"Parotitis as Extrapulmonary Tuberculosis:"

The mycobacterium that cause tuberculosis can also cause parotid infection. Those infected tend to have enlarged, nontender, but moderately painful glands. The diagnosis is made by typical chest radiograph findings, cultures, or histologic diagnosis after the gland has been removed. When diagnosed and treated with antitubercular medications, the gland may return to normal in 1–3 months.

"Acute viral parotitis (mumps):"

The most common viral cause of parotitis is mumps. Routine vaccinations have dropped the incidence of mumps to a very low level. Mumps resolves on its own in about ten days.

"HIV parotitis:" Generalized lymphadenopathy has long been associated with HIV, but the localized enlargement of the parotid gland is less well known.

In medicine, agenesis () refers to the failure of an organ to develop during embryonic growth and development due to the absence of primordial tissue. Many forms of agenesis are referred to by individual names, depending on the organ affected:

- Agenesis of the corpus callosum - failure of the Corpus callosum to develop

- Renal agenesis - failure of one or both of the kidneys to develop

- Phocomelia - failure of the arms or legs to develop

- Penile agenesis - failure of penis to develop

- Müllerian agenesis - failure of the uterus and part of the vagina to develop

- Agenesis of the gallbladder - failure of the Gallbladder to develop. A person may not realize they have this condition unless they undergo surgery or medical imaging, since the gallbladder is neither externally visible nor essential.

Eye agenesis is a medical condition in which people are born with no eyes.