Empty nose syndrome has been observed to affect a small proportion of people who have undergone surgery to the nose or sinuses, particularly those who have undergone turbinectomy (a procedure that removes some of the bones in the nasal passage). The incidence of ENS is variable and has not yet been quantified, but it is considered rare.

Untreated, the condition can cause significant and longterm physical and emotional distress in some people; some of the initial presentations on the condition described people who committed suicide. It is difficult to determine what treatments are safe and effective, and to what extent, in part because the diagnosis itself is unclear.

Initial treatment is similar to atrophic rhinitis, namely keeping the nasal mucosa moist with saline or oil-based lubricants and treating pain and infection as they arise; adding menthol to lubricants may be helpful in ENS, as may be use of a cool mist humidifer at home. For people with anxiety, depression, or who are obsessed with the feeling that they can't breathe, psychiatric or psychological care may be helpful.

In some people, surgery to restore missing or reduced turbinates may be beneficial.

A 2015 meta-analysis identified 128 people treated with surgery from eight studies that were useful to pool, with an age range of 18 to 64, most of whom had been suffering ENS symptoms for many years. The most common surgical approach was creating a pocket under the mucosa and implanting material - the amount and location were based on the judgement of the surgeon. In about half the cases a filler such as noncellular dermis, a medical-grade porous high-density polyethylene, or silastic was used and in about 40% cartilage taken from the person or from a cow was used. In a few cases hyaluronic acid was injected and in a few others tricalcium phosphate was used. There were no complications caused by the surgery, although one person was over-corrected and developed chronic rhinosinusitis and two people were under-corrected. The hyaluronic acid was completely resorbed in the three people who received it at the one year follow up, and in six people some of the implant came out, but this did not affect the result as enough remained. About 21% of the people had no or marginal improvement but the rest reported significant relief of their symptoms. Since none of the studies used placebo or blinding there may be a strong placebo effect or bias in reporting.

Causes can be remembered by mnemonic HERNIA:

- Hereditary factors: the disease runs in families

- Endocrine imbalance: the disease tends to start at puberty and mostly involves females

- Racial factors: whites are more susceptible than natives of equatorial Africa

- Nutritional deficiency: vitamins A or D, or iron

- Infection: "Klebsiella ozaenae", diphtheroids, "Proteus vulgaris", "E. coli", etc.

- Autoimmune factors: viral infection or some other unidentified insult may trigger antigenicity of the nasal mucosa.

Specific infections, such as syphilis, lupus, leprosy and rhinoscleroma, may cause destruction of the nasal structures leading to atrophic changes. Atrophic rhinitis can also result from long-standing purulent sinusitis or radiotherapy of the nose, or as a complication of surgery of the turbinates. The United Kingdom National Health Service has stated that "Most cases of atrophic rhinitis in the UK occur when the turbinates are damaged or removed during surgery". Some authors refer to as Atrophic rhinitis secondary to sinus surgery as the empty nose syndrome.

Common issues that lead to overuse of topical decongestants:

- Deviated septum

- Upper respiratory tract infection

- Vasomotor rhinitis

- Cocaine use and other stimulant abuse

- Pregnancy (these products are not considered safe for pregnancy)

- Chronic rhinosinusitis

- Hypertrophy of the inferior turbinates

Alcoholism is mistakenly attributed as a cause of this issue. Alcohol however may cause increased flushing in those affected.

A unibrow is part of normal human variation, but can also stem from developmental disorders. A unibrow is a recognized feature of Cornelia De Lange syndrome, a genetic disorder whose main features include moderate to severe learning difficulties, limb abnormalities such as oligodactyly (fewer than normal fingers or toes) and phocomelia (malformed limbs), and facial abnormalities including a long philtrum (the slight depression/line between the nose and mouth).

Other medical conditions associated with a unibrow include:

- Waardenburg Syndrome;

- Patau Syndrome;

- Smith-Lemli-Opitz Syndrome;

- Sanfilippo Syndrome;

- 3p Deletion Syndrome;

- Chromosome Deletion Dillan 4p Syndrome (Wolf–Hirschhorn Syndrome);

- Gorlin Syndrome (Basal Cell Nevus Syndrome);

- Frontometaphyseal Dysplasia;

- ATRX Syndrome;

- Chromosome 9q34 Microdeletion Syndrome or Kleefstra syndrome.

Rhinorrhea can also occur when individuals with allergies to certain substances, such as pollen, dust, latex, soy, shellfish, or animal dander, are exposed to these allergens. In people with sensitized immune systems, the inhalation of one of these substances triggers the production of the antibody immunoglobulin E (IgE), which binds to mast cells and basophils. IgE bound to mast cells are stimulated by pollen and dust, causing the release of inflammatory mediators such as histamine. In turn, this causes, among other things, inflammation and swelling of the tissue of the nasal cavities as well as increased mucus production. Particulate matter in polluted air and chemicals such as chlorine and detergents, which can normally be tolerated, can make the condition considerably worse.

It can usually be corrected with augmentation rhinoplasty by filling the dorsum of nose with cartilage, bone or synthetic implant. If the depression is only cartilaginous, cartilage is taken from the nasal septum or auricle and laid in single or multiple layers. If deformity involves both cartilage and bone, cancellous bone from iliac crest is the best replacement. Autografts are preferred over allografts. Saddle deformity can also be corrected by synthetic implants of teflon or silicon, but they are likely to be extruded.

Nasal polyps resulting from chronic rhinosinusitis affect approximately 4.3% of the population. Nasal polyps occur more frequently in men than women and are more common as people get older, increasing drastically after the age of 40.

Of people with chronic rhinosinusitis, 10% to 54% also have allergies. An estimated 40% to 80% of people with sensitivity to aspirin will develop nasal polyposis. In people with cystic fibrosis, nasal polyps are noted in 37% to 48%.

During the summer months, allergies are a common cause of throat irritation. Many individuals have allergies to pet dander, dust, mites, pollen and molds that can trigger an allergic reaction which present with runny nose, red eyes, congested nose and throat irritation. Often a dry cough may also be present.

If caused by a head injury, rhinorrhea can be a much more serious condition. A basilar skull fracture can result in a rupture of the barrier between the sinonasal cavity and the anterior cranial fossae or the middle cranial fossae. This rupture can cause the nasal cavity to fill with cerebrospinal fluid. This condition, known as cerebrospinal fluid rhinorrhoea or CSF rhinorrhea, can lead to a number of serious complications and possibly death if not addressed properly.

A unibrow (or monobrow; called synophrys in medicine) is a single eyebrow created when the two eyebrows meet in the middle above the bridge of the nose. The hair above the bridge of the nose is usually of the same color and thickness as the eyebrows, giving the appearance that they converge to form one uninterrupted line of hair.

Throat irritation can refer to a dry cough, a scratchy feeling at the back of the throat, or a sensation of a lumpy feeling or something stuck at the back of the throat

The causes of nosebleeds can generally be divided into two categories, local and general factors, although a significant number of nosebleeds occur with no obvious cause.

The cause of arrhinia is not known. Akkuzu's study of the literature found that all cases had presented a normal antenatal history.

Rhinophyma is a slowly progressive condition due to hypertrophy of the sebaceous glands of the tip of the nose often seen in cases of long-standing acne rosacea; it is not a neoplasm. It presents as a pink, lobulated mass over the nose with superficial vascular dilation; it mostly affects men past middle age. Patients seek advice because of the perceived unsightly appearance of the enlargement, or obstruction in breathing and vision.

The common cold is the most common human disease and affects people all over the globe. Adults typically have two to five infections annually, and children may have six to ten colds a year (and up to twelve colds a year for school children). Rates of symptomatic infections increase in the elderly due to declining immunity.

Native Americans and Inuit are more likely to be infected with colds and develop complications such as otitis media than Caucasians. This may be explained by issues such as poverty and overcrowding rather than by ethnicity.

Saddle nose is a condition associated with nasal trauma, congenital syphilis, relapsing polychondritis, granulomatosis with polyangiitis, cocaine abuse, and leprosy, among other conditions. The most common cause is nasal trauma. It is characterized by a loss of height of the nose, because of the collapse of the bridge. The depressed nasal dorsum may involve bony, cartilaginous or both bony and cartilaginous components of the nasal dorsum.

The common cold is generally mild and self-limiting with most symptoms generally improving in a week. Half of cases go away in 10 days and 90% in 15 days. Severe complications, if they occur, are usually in the very old, the very young, or those who are immunosuppressed. Secondary bacterial infections may occur resulting in sinusitis, pharyngitis, or an ear infection. It is estimated that sinusitis occurs in 8% and ear infection in 30% of cases.

A nosebleed, also known as epistaxis, is the common occurrence of bleeding from the nose. It is usually noticed when the blood drains out through the nostrils.

There are two types: anterior (the most common), and posterior (less common, more likely to require medical attention). Sometimes in more severe cases, the blood can come up the nasolacrimal duct and out from the eye. Fresh blood and clotted blood can also flow down into the stomach and cause nausea and vomiting.

Although the sight of large amounts of blood can be alarming and may warrant medical attention, nosebleeds are rarely fatal, accounting for only 4 of the 2.4 million deaths in the U.S. in 1999. About 60% of people have a nosebleed at some point in their life. About 10% of nosebleeds are serious.

Nasal congestion is the blockage of the nasal passages usually due to membranes lining the nose becoming swollen from inflamed blood vessels.

Nasal decongestants target the discomfort directly. These come as nasal sprays, inhalers, and as oral pills.

Nasal congestion has many causes and can range from a mild annoyance to a life-threatening condition. Most people prefer to breathe through the nose (historically referred to as "obligate nasal breathers"). Nasal congestion in an infant in the first few months of life can interfere with breastfeeding and cause life-threatening respiratory distress; in older children and adolescents it is often just an annoyance but can cause other difficulties.

Nasal congestion can interfere with the hearing and speech. Significant congestion may interfere with sleep, cause snoring, and can be associated with sleep apnea. In children, nasal congestion from enlarged adenoids has caused chronic sleep apnea with insufficient oxygen levels and hypoxia, as well as right-sided heart failure. The problem usually resolves after surgery to remove the adenoids and tonsils, however the problem often relapses later in life due to craniofacial alterations from chronic nasal congestion.

Nasal congestion can also cause mild facial and head pain, and a degree of discomfort, often from allergies or the common cold.

Arhinia, also called nasal agenesis, is the congenital partial or complete absence of the nose at birth. It is an extremely rare condition, with 47 reported cases in the history of modern medicine. It is generally classified as a craniofacial abnormality.

In teratology, proboscis is a blind-ended, tubelike structure, commonly located in the midface.

Proboscis formation are classified in four general types: holoprosencephalic proboscis, lateral nasal proboscis, supernumerary proboscis, and disruptive proboscis.

- Holoprosencephalic proboscis is found in holoprosencephaly. In cyclopia or ethmocephaly, proboscis is an abnormally formed nose. In cyclopia, a single median eye is associated with arrhinia (absence of the nose) and usually with proboscis formation above the eye. In ethmocephaly, two separate hypoteloric eyes are associated with arrhinia and supraocular proboscis formation. In cebocephaly, no proboscis formation occurs, but a single-nostril nose is present.

- Lateral nasal proboscis (proboscis lateralis) is a tubular proboscis-like structure and represents incomplete formation of one side of the nose; it is found instead of a nostril. The olfactory bulb is usually rudimentary on the involved side. The lacrimal duct (tear duct), nasal bone, nasal cavity, vomer, maxillary sinus, cribriform plate, and ethmoid cells are often missing on the involved side. Ocular hypertelorism may be present. The proboscis lateralis is a rare nasal anomaly.

- Supernumerary proboscis (Accessory proboscis) is found when both nostrils are formed and a proboscis occurs additionally. Accessory proboscis arise from a supernumerary olfactory placode.

- Disruptive proboscis occur if an early embryonic hamartoneoplastic lesion arises in the primitive prosencephalon.

Rhinitis medicamentosa (or RM) is a condition of rebound nasal congestion brought on by extended use of topical decongestants (e.g., oxymetazoline, phenylephrine, xylometazoline, and naphazoline nasal sprays) and certain oral medications (e.g., sympathomimetic amines and various 2-imidazolines) that constrict blood vessels in the lining of the nose.