Although this is a congenital lesion, airway sounds typically begin at age 4–6 weeks. Until that age, inspiratory flow rates may not be high enough to generate the sounds. Symptoms typically peak at age 6–8 months and remit by age 2 years.

Late-onset laryngomalacia may be a distinct entity, which can present after age of 2 years

Laryngocele refers to a congenital anomalous air sac communicating with the cavity of the larynx, which may bulge outward on the neck.

It may also be acquired, as seen in glassblowers, due to continual forced expiration producing increased pressures in the larynx which leads to dilatation of the laryngeal ventricle (Sinus of Morgagni). It is also seen in people with chronic obstructive airway disease.

The physician will ask some questions about the baby’s health problems and may recommend a flexible laryngoscopy to further evaluate the infant's condition.

Congenital cysts of the larynx with incidence of about 1.8 in 100,000 newborns.

Laryngeal cysts form 4% of all laryngeal tumors or about 5% of benign laryngeal lesions. Prevalence is about equal between the sexes.

These lesions usually present in neonates, although they may not come to clinical attention until adulthood (for cosmetic reasons). There is no gender predilection. They are present in approximately 3-6 per 1000 live births.

Laryngeal papillomatosis is caused by human papillomavirus (HPV), most frequently by types 6 and 11. The mode of transmission is found to differ depending on age. The disease is typically separated into two forms, juvenile and adult papillomatosis, based on whether it develops before or after 20 years of age. The juvenile form is generally transmitted through contact with a mother’s infected vaginal canal during childbirth. Less is known about transmission in the adult form of this disease, though oral sex has been implicated as a potential mode of transmission. However, it is uncertain whether oral sex would directly transmit the virus or activate the dormant virus that was transmitted at childbirth.

In general, physicians are unsure why only certain people who have been exposed to the HPV types implicated in the disease develop laryngeal papillomatosis. In the case of the juvenile form of the disease, the likelihood of a child born of an infected mother developing laryngeal papillomatosis is low (between 1 in 231 to 1 in 400), even if the mother’s infection is active. Risk factors for a higher likelihood of transmission at childbirth include the first birth, vaginal birth, and teenage mother.

Laryngeal cysts are cysts involving the larynx or more frequently supraglottic locations, such as epiglottis and vallecula. Usually they do not extend to the thyroid cartilage. They may be present congenitally or may develop eventually due to degenerative cause. They often interfere with phonation.

The evolution of laryngeal papillomatosis is highly unpredictable and is characterized by modulation of its severity and variable rate of progression across individuals. While instances of total recovery are observed, the condition is often persistent and lesions can reappear even after treatment. Factors that might affect the clinical course of the condition include: the HPV genotype, the age at onset, the elapsed time between the diagnosis and first treatment in addition to previous medical procedures. Other factors, albeit controversial, such as smoking or the presence gastroesophageal reflux disease might also play a role in the progression of the disease.

The papillomas can travel past the larynx and infect extralaryngeal sites. In more aggressive cases, infection of the lungs can occur with progressive airway obstruction. Although rare (less than 1% of people with laryngeal papillomatosis), transformation from a benign form to a malignant form is also observed. Death can result from these complications (morbidity rate is around 1-2%).

The adenoids, like all lymphoid tissue, enlarge when infected. Although lymphoid tissue does act to fight infection, sometimes bacteria and viruses can lodge within it and survive. Chronic infection, either viral or bacterial, can keep the pad of adenoids enlarged for years, even into adulthood. Some viruses, such as the Epstein-Barr Virus, can cause dramatic enlargement of lymphoid tissue. Primary or reactivation infections with Epstein Barr Virus, and certain other bacteria and viruses, can even cause enlargement of the adenoidal pad in an adult whose adenoids had previously become atrophied.

Besides complications of surgery and anesthesia in general, there may be drainage, swelling, or redness of the incision, gagging or coughing during eating or drinking, or pneumonia due to aspiration of food or liquids. Undesirable complications are estimated to occur in 10-30% of cases. If medical therapy is unsuccessful and surgery cannot be performed due to concurrent disease (such as heart or lung problems) or cost, euthanasia may be necessary if the animal's quality of life is considered unacceptable due to the disease.

There is some low quality evidence suggesting that mometasone may lead to symptomatic improvement in children with adenoid hypertrophy.

Surgical removal of the adenoids is a procedure called adenoidectomy. Carried out through the mouth under a general anaesthetic, adenoidectomy involves the adenoids being curetted, cauterised, lasered, or otherwise ablated. Adenoidectomy is most often performed because of nasal obstruction, but is also performed to reduce middle ear infections and fluid (otitis media). The procedure is often carried out at the same time as a tonsillectomy, since the adenoids can be clearly seen and assessed by the surgeon at that time.

An accessory auricle is considered a developmental anomaly resulting from the persistence of a structure which variably recapitulates the normal external ear.

The inheritance of Impossible syndrome is suspected to be autosomal recessive, which means the affected gene is located on an autosome, and two copies of the gene - one from each parent - are required to have an infant with the disorder.

There are three types of tracheomalacia:

- Type 1—congenital, sometimes associated with tracheoesophageal fistula or esophageal atresia

- Type 2—extrinsic compression sometimes due to vascular rings

- Type 3—acquired due to chronic infection or prolonged intubation or inflammatory conditions like relapsing polychondritis

Smoking is the most important risk factor for laryngeal cancer. Death from laryngeal cancer is 20 times more likely for heaviest smokers than for nonsmokers. Heavy chronic consumption of alcohol, particularly alcoholic spirits, is also significant. When combined, these two factors appear to have a synergistic effect.

Some other quoted risk factors are likely, in part, to be related to prolonged alcohol and tobacco consumption. These include low socioeconomic status, male sex, and age greater than 55 years.

People with a history of head and neck cancer are known to be at higher risk (about 25%) of developing a second cancer of the head, neck, or lung. This is mainly because in a significant proportion of these patients, the aerodigestive tract and lung epithelium have been exposed chronically to the carcinogenic effects of alcohol and tobacco. In this situation, a field change effect may occur, where the epithelial tissues start to become diffusely dysplastic with a reduced threshold for malignant change. This risk may be reduced by quitting alcohol and tobacco.

Mild cases are managed by limiting activity, keeping a healthy body weight, and avoiding exposure to high ambient temperatures. Mild sedatives can be used to decrease anxiety and panting and therefore improve respiration. Corticosteroids may also be administered in acute cases to decrease inflammation and edema of the larynx.

Severe acute symptoms, such as difficulty breathing, hyperthermia, or aspiration pneumonia, must be stabilized with sedatives and oxygen therapy and may require steroid or antibiotic medications. Sometimes a tracheotomy is required to allow delivery of oxygen. Once the patient is stabilized, surgical treatment may be beneficial especially when paralysis occurs in both aretynoid cartilages (bilateral paralysis). The surgery (aretynoid lateralization, or a "laryngeal tieback") consists of suturing one of the aretynoid cartilages in a maximally abducted (open) position. This reduces the signs associated with inadequate ventilation (such as exercise intolerance or overheating) but may exacerbate the risk of aspiration and consequent pneumonia. Tying back only one of the aretynoid cartilages instead of both helps reduce the risk of aspiration. Afterwards the dog will still sound hoarse, and will need to be managed in the same way as those with mild cases of LP.

Recent studies have found that many dogs with laryngeal paralysis have decreased motility of their esophagus. Animals with a history of regurgitation or vomiting should be fully evaluated for esophageal or other gastrointestinal disorders. Dogs with megaesophagus or other conditions causing frequent vomiting or regurgitation are at high risk for aspiration pneumonia after laryngeal tie-back. Permanent tracheostomy is an alternative surgical option for these dogs to palliate their clincical signs.

Tracheomalacia is a condition where the cartilage that keeps the airway (trachea) open is soft such that the trachea partly collapses especially during increased airflow. The usual symptom is stridor when a person breathes out.

The trachea normally opens slightly during breathing in and narrows slightly during breathing out. These processes are exaggerated in tracheomalacia, leading to airway collapse on breathing out.

If the condition extends further to the large airways (bronchi) (if there is also bronchomalacia), it is termed tracheobronchomalacia. The same condition can also affect the larynx, which is called laryngomalacia. The term is from "trachea" and the Greek μαλακία, "softening"

Minor degrees of curvature are common. Reports of incidence vary between 1% and 19.5%.

Pancreas divisum in individuals with no symptoms does not require treatment. Treatment of those with symptoms varies and has not been well established. A surgeon may attempt a sphincterotomy by cutting the minor papilla to enlarge the opening and allow pancreatic enzymes to flow normally. During surgery, a stent may be inserted into the duct to ensure that the duct will not close causing a blockage. This surgery can cause pancreatitis in patients, or in rare cases, kidney failure and death.

An association with adenoma of the minor papilla has been reported.

Clinodactyly is an autosomal dominant trait that has variable expressiveness and incomplete penetrance.

Clinodactyly can be passed through inheritance and presents as either an isolated anomaly or a component manifestation of a genetic syndrome. Many syndromes are associated with clinodactyly, including Down Syndrome, Turner syndrome, Aarskog syndrome, Carpenter syndrome, Seckel syndrome, Cornelia de Lange syndrome, orofaciodigital syndrome 1, 13q deletion syndrome, XXYY syndrome and Silver–Russell syndrome.

When identified prenatally, for example during obstetric ultrasonography, it may be an indication for intrauterine sampling for fetal chromosome analysis as it is statistically correlated with increased risk of chromosome aberration in the fetus.

Midline cervical clefts are a rare congenital anomaly resulting from incomplete fusion during embryogenesis of the first and second branchial arches in the ventral midline of the neck. The condition presents as a midline cutaneous defect of the anterior neck with a skin projection or sinus, or as a subcutaneous erythematous fibrous cord. Surgical excision is the preferred treatment.

Opitz G/BBB Syndrome is a rare genetic condition caused by one of two major types of mutations: MID1 mutation on the short (p) arm of the X chromosome or a mutation of the 22q11.2 gene on the 22nd chromosome. Since it is a genetic disease, it is an inherited condition. However, there is an extremely wide variability in how the disease presents itself.

In terms of prevention, several researchers strongly suggest prenatal testing for at-risk pregnancies if a MID1 mutation has been identified in a family member. Doctors can perform a fetal sex test through chromosome analysis and then screen the DNA for any mutations causing the disease. Knowing that a child may be born with Opitz G/BBB syndrome could help physicians prepare for the child’s needs and the family prepare emotionally. Furthermore, genetic counseling for young adults that are affected, are carriers or are at risk of carrying is strongly suggested, as well (Meroni, Opitz G/BBB syndrome, 2012). Current research suggests that the cause is genetic and no known environmental risk factors have been documented. The only education for prevention suggested is genetic testing for at-risk young adults when a mutation is found or suspected in a family member.

Impossible Syndrome, or Chondrodysplasia situs inversus imperforate anus polydactyly, is a complex combination of human congenital malformations (birth defects).

The malformations include chondrodysplasia (improper growth of bone and cartilage), situs inversus totalis (chest and abdominal organs all a mirror image of normal), cleft larynx and epiglottis, hexadactyly (six digits) on hands and feet, diaphragmatic hernia, pancreatic abnormalities, kidney abnormal on one side and absent on the other side, micropenis and ambiguous genitalia, and imperforate anus.

Only one case of Impossible Syndrome has been reported; the infant was premature and stillborn.

Congenital stenosis of vena cava is a congenital anomaly in which the superior vena cava or inferior vena cava has an aberrant interruption or coarctation.

In some cases, it can be asymptomatic, and in other cases it can lead to fluid accumulation and cardiopulmonary collapse.

The surgical treatment involves the resection of the extracranial venous package and ligation of the emissary communicating vein. In some cases of SP, surgical excision is performed for cosmetic reasons. The endovascular technique has been described by transvenous approach combined with direct puncture and the recently endovascular embolization with Onyx.