Clinical examination and x rays can help diagnose the condition. For examples :

- Valsalva test (nose blowing test): Ask the patient to pinch the nostrils together and open the mouth, then blow gently through the nose. Observe if there is passage of air or bubbling of blood in the post extraction alveolus as the trapped air from closed nostrils is forced into the mouth through any oroantral communication. Gentle suction applied to the socket often produces a characteristic hollow sound.

- Perform a complete extra- and intra-oral examination using a dental mirror under good lighting, look for granulation tissue in the socket and openings into the antrum.

- Panoramic radiograph or paranasal computed tomography can help to locate the fistula, the size of it and to determine the presence of sinusitis and other foreign bodies. Other methods like radiographs (occipitomental, OPG and periapical views) can also be used to confirm the presence of any oroantral fistulas.

- To test the patency of communication the patient is asked to rinse the mouth or water is flushed in the tooth socket.

- Unilateral epistaxis is seen in case of collection of blood in the sinus cavity.

- Do not probe or irrigate the site, because it may lead to sinusitis or push foreign bodies, such as contaminated fragments, or oral flora further into the antrum. Hence, leading to the formation of a new fistula or widen an existing one.

Oroantral fistula (OAF) is an abnormal condition of the face where the maxillary sinus is exposed to the oral cavity through an epithelialised fistula. This term signifies pathology and it is not to be confused with oroantral communication (OAC). OAC if left untreated can either heal spontaneously or progress into OAF. The fistulous opening may be situated on the alveolus.

Occasionally a preauricular sinus or cyst can become infected.

Most preauricular sinuses are asymptomatic, and remain untreated unless they become infected too often. Preauricular sinuses can be excised with surgery which, because of their close proximity to the facial nerve, is performed by an appropriately trained, experienced surgeon (e.g. a specialist General Surgeon, a Plastic Surgeon, an otolaryngologist (Ear, Nose, Throat surgeon) or an Oral and Maxillofacial Surgeon).

Preauricular sinuses and cysts result from developmental defects of the first and second pharyngeal arches. This and other congenital ear malformations are sometimes associated with renal anomalies. They may be present in Beckwith–Wiedemann syndrome, and in rare cases, they may be associated with branchio-oto-renal syndrome.

Most branchial cleft cysts present as a smooth, slowly enlarging lateral neck mass that may increase in size after an upper respiratory tract infection. The fistulas, when present, are asymptomatic, but may become infected.

Thyroglossal duct cysts most often present with a palpable asymptomatic midline neck mass above the level of the hyoid bone. The mass on the neck moves during swallowing or on protrusion of the tongue because of its attachment to the tongue via the tract of thyroid descent. Some patients will have neck or throat pain, or dysphagia.

The persistent duct or sinus can promote oral secretions, which may cause cysts to become infected. Up to half of thyroglossal cysts are not diagnosed until adult life. The tract can lie dormant for years or even decades, until some kind of stimulus leads to cystic dilation. Infection can sometimes cause the transient appearance of a mass or enlargement of the cyst, at times with periodic recurrences. Spontaneous drainage may also occur. Differential diagnosis are ectopic thyroid, enlarged lymph nodes, dermoid cysts and goiter.

Thyroglossal cyst usually presents as a midline neck lump (in the region of the hyoid bone) that is usually painless, smooth and cystic, though if infected, pain can occur. There may be difficulty breathing, dysphagia (difficulty swallowing), or dyspepsia (discomfort in the upper abdomen), especially if the cyst becomes large.

The most common location for a thyroglossal cyst is midline or slightly off midline, between the isthmus of the thyroid and the hyoid bone or just above the hyoid bone. A thyroglossal cyst can develop anywhere along a thyroglossal duct, though cysts within the tongue or in the floor of the mouth are rare.A thyroglossal cyst will move upwards with protrusion of the tongue.Thyroglossal cysts are associated with an increased incidence of ectopic thyroid tissue. Occasionally, a lingual thyroid can be seen as a flattened strawberry-like lump at the base of the tongue.

A branchial cleft cyst is a cyst in the skin of the lateral part of the neck. It can but does not necessarily have an opening to the skin surface called a fistula. The cause is usually a developmental abnormality arising in the early prenatal period, typically failure of obliteration of the second branchial cleft, i.e. failure of fusion of the second and third branchial arches. Less commonly, the cysts can develop from the first, third, or fourth clefts, and their location and the location of associated fistulas differs accordingly.

An infected thyroglossal duct cyst can occur when it is left untreated for a certain amount of time or simply when a thyroglossal duct cyst hasn't been suspected. The degree of infection can be examined as major rim enhancement has occurred, located inferior to the hyoid bone. Soft tissue swelling occurs, along with airway obstruction and trouble swallowing, due to the rapid enlargement of the cyst.

With infections, there can be rare cases where an expression of fluid is projected into the pharynx causing other problems within the neck.

PLF is a cause of dizziness, imbalance, and hearing loss—any or all of these symptoms can exist. Vertigo (an illusion of motion) is not common in this disorder. The most common cause of this fistula is head or ear trauma. Rapid increases of intracranial pressure can also result in a PLF. Rarely, these fistulas can be congenital, leading to progressive hearing loss and vertigo in childhood. It has also been a complication of a stapedectomy.

A labyrinthine fistula is an abnormal opening in the bony capsule of the inner ear, resulting in leakage of the perilymph from the Cochlea into the middle ear. This includes specifically a perilymph fistula (PLF), an abnormal connection between the fluid of the inner ear and the air-filled middle ear. This connection is caused by a rupture of the round window that separate the inner and middle ear. Another type of l.f. is a semicircular canal dehiscence, which allows the inner ear to be influenced by the intracranial pressure directly.

A salivary gland fistula (plural "fistulae") is a fistula (i.e. an abnormal, epithelial-lined tract) involving a salivary gland or duct.

Salivary gland fistulae are almost always related to the parotid gland or duct, although the submandibular gland is rarely the origin.

The fistula can communicate with the mouth (usually causing no symptoms), the paranasal sinuses (giving rhinorrhea) or the facial skin (causing saliva to drain onto the skin).

The usual cause is trauma, however salivary fistula can occur as a complication of surgery, or if the duct becomes obstructed with a calculus.

Most parotid fistulae heal by themselves within a few weeks.

Laryngeal cleft is usually diagnosed in an infant after they develop problems with feeding, such as coughing, cyanosis (blue lips) and failing to gain weight over time. Pulmonary infections are also common. The longer the cleft, the more severe are the symptoms. Laryngeal cleft is suspected after a video swallow study (VSS) shows material flowing into the airway rather than the esophagus, and diagnosis is confirmed through endoscopic examination, specifically microlaryngoscopy and bronchoscopy. If a laryngeal cleft is not seen on flexible nasopharyngoscopy, that does not mean that there is not one there. Laryngeal clefts are classified into four types according to Benjamin and Inglis. Type I clefts extend down to the vocal cords; Type II clefts extend below the vocal cords and into the cricoid cartilage; Type III clefts extend into the cervical trachea and Type IV clefts extend into the thoracic trachea. Subclassification of type IV clefts into Type IVA (extension to 5 mm below the innomate artery) and Type IV B (extension greater than 5 mm below the innominate artery) may help with preoperative selection of those who can be repaired via transtracheal approach (Type IV A) versus a cricotracheal separation approach (type IV B).

Anal fistulae can present with the following symptoms:

- skin maceration

- pus, serous fluid and/or (rarely) feces discharge — can be bloody or purulent

- pruritus ani — itching

- depending on presence and severity of infection:

Symptoms of cuffitis mimic those of pouchitis. In addition, patients with cuffitis often present with small volume bloody bowel movements. Often, cuffitis can produce the appearance of bright red blood on tissue.

Twenty to 27% of individuals with a laryngeal cleft also have a tracheoesophageal fistula and approximately 6% of individuals with a fistula also have a cleft. Other congenital anomalies commonly associated with laryngeal cleft are gastro-oesophageal reflux, tracheobronchomalacia, congenital heart defect, dextrocardia and situs inversus. Laryngeal cleft can also be a component of other genetic syndromes, including Pallister-Hall syndrome and G syndrome (Opitz-Friaz syndrome).

Paraproctitis is a purulent inflammation of the cellular tissues surrounding the rectum. The most frequent cause is penetration of bacterial flora from the rectum into the surrounding cellular tissues, which may occur through an anal fissure. The inflammation is sometimes limited to the formation of an abscess, and in some cases it spreads for a considerable distance and may be complicated by sepsis.

The symptoms are acute pain in the rectal region, tenderness during defecation, elevated body temperature, and the appearance of an infiltrate in the anal region or on the buttocks. An unlanced abscess may burst and a fistula form. The disease becomes chronic after recurrences. Treatment includes administration of antibiotics and anti-inflammatory agents and, in the suppurative stage, surgical lancing of the abscess.

Tracheoesophageal fistula is suggested in a newborn by copious salivation associated with choking, coughing, vomiting, and cyanosis coincident with the onset of feeding. Esophageal atresia and the subsequent inability to swallow typically cause polyhydramnios in utero. Rarely it may present in an adult.

Anal fistula (plural fistulae), or fistula-in-ano, is a chronic abnormal communication between the epithelialised surface of the anal canal and (usually) the perianal skin. An anal fistula can be described as a narrow tunnel with its internal opening in the anal canal and its external opening in the skin near the anus. Anal fistulae commonly occur in people with a history of anal abscesses. They can form when anal abscesses do not heal properly.

Anal fistulae originate from the anal glands, which are located between the internal and external anal sphincter and drain into the anal canal. If the outlet of these glands becomes blocked, an abscess can form which can eventually extend to the skin surface. The tract formed by this process is a fistula.

Abscesses can recur if the fistula seals over, allowing the accumulation of pus. It can then extend to the surface again - repeating the process.

Anal fistulae "per se" do not generally harm, but can be very painful, and can be irritating because of the drainage of pus (it is also possible for formed stools to be passed through the fistula). Additionally, recurrent abscesses may lead to significant short term morbidity from pain and, importantly, create a starting point for systemic infection.

Treatment, in the form of surgery, is considered essential to allow drainage and prevent infection. Repair of the fistula itself is considered an elective procedure which many patients opt for due to the discomfort and inconvenience associated with an actively draining fistula.

Surgical repair can sometimes result in complications, including:

- Stricture, due to gastric acid erosion of the shortened esophagus

- Leak of contents at the point of anastomosis

- Recurrence of fistula

- Gastro-esophageal reflux disease

- Dysphagia

- Asthma-like symptoms, such as persistent coughing/wheezing

- Recurrent chest infections

- Tracheomalacia

Vesicovaginal fistula, or VVF, is an abnormal fistulous tract extending between the bladder (or vesico) and the vagina that allows the continuous involuntary discharge of urine into the vaginal vault.

In addition to the medical sequela from these fistulas, they often have a profound effect on the patient's emotional well-being.

Cuffitis is inflammation at the anal transition zone or “cuff” created as a result of ileal pouch-anal anastomosis (IPAA). It is considered a variant form of ulcerative colitis that occurs in the rectal cuff. Cuffitis is a common complication of IPAA, particularly when a stapled anastomosis without mucosectomy procedure has been used.

Vesicovaginal fistula (VVF) is a subtype of female urogenital fistula (UGF).

Symptoms include hemoptysis, and/or massive hemorrhage which result from the formation of a fistula between the trachea and the brachiocephalic artery. The primary threat is respiratory compromise leading to dyspnea and cyanosis. Patients can later present with hypovolemic shock which include symptoms of tachycardia, cyanosis, cold and clammy skin, dizziness, confusion, and fatigue. Patients may also develop septicemia.

A urachal fistula is a congenital disorder caused by the persistence of the allantois (later, urachus), the structure that connects an embryo's bladder to the yolk sac. Normally, the urachus closes off to become the median umbilical ligament; however, if it remains open, urine can drain from the bladder to an opening by the umbilicus.

An enterocutaneous fistula (ECF) is an abnormal communication between the small or large bowel and the skin that allows the contents of the stomach or intestines to leak through an opening in the skin.