Approximately one half of drug-related taste distortions are caused by a zinc deficiency. Many medications are known to chelate, or bind, zinc, preventing the element from functioning properly. Due to the causal relationship of insufficient zinc levels to taste disorders, research has been conducted to test the efficacy of zinc supplementation as a possible treatment for dysgeusia. In a randomized clinical trial, fifty patients suffering from idiopathic dysgeusia were given either zinc or a lactose placebo. The patients prescribed the zinc reported experiencing improved taste function and less severe symptoms compared to the control group, suggesting that zinc may be a beneficial treatment. The efficacy of zinc, however, has been ambiguous in the past. In a second study, 94% of patients who were provided with zinc supplementation did not experience any improvement in their condition. This ambiguity is most likely due to small sample sizes and the wide range of causes of dysgeusia. A recommended daily oral dose of 25–100 mg appears to be an effective treatment for taste dysfunction provided that there are low levels of zinc in the blood serum. There is not a sufficient amount of evidence to determine whether or not zinc supplementation is able to treat dysgeusia when low zinc concentrations are not detected in the blood.

The effects of drug-related dysgeusia can often be reversed by stopping the patient's regimen of the taste altering medication. In one case, a forty-eight-year-old woman who was suffering from hypertension was being treated with valsartan. Due to this drug's inability to treat her condition, she began taking a regimen of eprosartan, an angiotensin II receptor antagonist. Within three weeks, she began experiencing a metallic taste and a burning sensation in her mouth that ceased when she stopped taking the medication. When she began taking eprosartan on a second occasion, her dysgeusia returned. In a second case, a fifty-nine-year-old man was prescribed amlodipine in order to treat his hypertension. After eight years of taking the drug, he developed a loss of taste sensation and numbness in his tongue. When he ran out of his medication, he decided not to obtain a refill and stopped taking amlodipine. Following this self-removal, he reported experiencing a return of his taste sensation. Once he refilled his prescription and began taking amlodipine a second time, his taste disturbance reoccurred. These two cases suggest that there is an association between these drugs and taste disorders. This link is supported by the "de-challenge" and "re-challenge" that took place in both instances. It appears that drug-induced dysgeusia can be alleviated by reducing the drug's dose or by substituting a second drug from the same class.

The successful treatment of xerostomia is difficult to achieve and often unsatisfactory. This involves finding any correctable cause and removing it if possible, but in many cases it is not possible to correct the xerostomia itself, and treatment is symptomatic, and also focuses on preventing tooth decay through improving oral hygiene. Where the symptom is caused by hyposalivation secondary to underlying chronic disease, xerostomia can be considered permanent or even progressive. The management of salivary gland dysfunction may involve the use of saliva substitutes and/or saliva stimulants:

- Saliva substitutes – these include SalivaMAX, water, artificial salivas (mucin-based, carboxymethylcellulose-based), and other substances (milk, vegetable oil).

- Saliva stimulants – organic acids (ascorbic acid, malic acid), chewing gum, parasympathomimetic drugs (choline esters, e.g. pilocarpine hydrochloride, cholinesterase inhibitors), and other substances (sugar-free mints, nicotinamide).

Saliva substitutes can improve xerostomia, but tend not to improve the other problems associated with salivary gland dysfunction. Parasympathomimitic drugs (saliva stimulants) such as pilocarpine may improve xerostomia symptoms and other problems associated with salivary gland dysfunction, but the evidence for treatment of radiation-induced xerostomia is limited. Both stimulants and substitutes relieve symptoms to some extent. Salivary stimulants are probably only useful in people with some remaining detectable salivary function. A systematic review of the treatment of dry mouth found no strong evidence to suggest that a specific topical therapy is effective. The review reported limited evidence that oxygenated glycerol triester spray was more effective than electrolyte sprays. Sugar free chewing gum increases saliva production but there is no strong evidence that it improves symptoms. There is a suggestion that intraoral devices and integrated mouthcare systems may be effective in reducing symptoms, but there was a lack of strong evidence. A systematic review of the management of radiotherapy induced xerostomia with parasympathomimetic drugs found that there was limited evidence to support the use of pilocarpine in the treatment of radiation-induced salivary gland dysfunction. It was suggested that, barring any contraindications, a trial of the drug be offered in the above group (at a dose of five mg three times per day to minimize side effects). Improvements can take up to twelve weeks. However, pilocarpine is not always successful in improving xerostomia symptoms. The review also concluded that there was little evidence to support the use of other parasympathomimetics in this group.

A 2013 review looking at non-pharmacological interventions reported a lack of evidence to support the effects of electrostimulation devices, or acupuncture, on symptoms of dry mouth.

If a cause can be identified for a burning sensation in the mouth, then treatment of this underlying factor is recommended. If symptom persist despite treatment a diagnosis of BMS is confirmed. BMS has been traditionally treated by reassurance and with antidepressants, anxiolytics or anticonvulsants. A 2016 Cochrane review of treatment for burning mouth syndrome concluded that strong evidence of an effective treatment was not available. Other treatments which have been used include atypical antipsychotics, histamine receptor antagonists, and dopamine agonists.

Local damage and inflammation that interferes with the taste buds or local nervous system such as that stemming from radiation therapy, glossitis, tobacco use, and denture use also cause ageusia. Other known causes include loss of taste sensitivity from aging (causing a difficulty detecting salty or bitter taste), anxiety disorder, cancer, renal failure and liver failure.

Deficiency of vitamin B (niacin) and zinc can cause problems with the endocrine system, which may cause taste loss or alteration. Disorders of the endocrine system, such as Cushing's syndrome, hypothyroidism and diabetes mellitus, can cause similar problems. Ageusia can also be caused by medicinal side-effects from antirheumatic drugs such as penicillamine, antiproliferative drugs such as cisplatin, ACE inhibitors, and other drugs including azelastine, clarithromycin, terbinafine, and zopiclone.

There is no agreed treatment protocol. In most reported cases of ORS the attempted treatment was antidepressants, followed by antipsychotics and various psychotherapies. Little data are available regarding the efficacy of these treatments in ORS, but some suggest that psychotherapy yields the highest rate of response to treatment, and that antidepressants are more efficacious than antipsychotics (response rates 78%, 55% and 33% respectively). According to one review, 43% of cases which showed overall improvement required more than one treatment approach, and in only 31% did the first administered treatment lead to some improvement.

Pharmacotherapies that have been used for ORS include antidepressants, (e.g. selective serotonin reuptake inhibitors, tricyclic antidepressants, monoamine oxidase inhibitors), antipsychotics, (e.g. blonanserin, lithium, chlorpromazine), and benzodiazepines. The most common treatment used for ORS is SSRIs. Specific antidepressants that have been used include clomipramine.

Psychotherapies that have been used for ORS include cognitive behavioral therapy, eye movement desensitization and reprocessing.

BMS is benign (importantly, it is not a symptom of oral cancer), but as a cause of chronic pain which is poorly controlled, it can detriment quality of life, and may become a fixation which cannot be ignored, thus interfering with work and other daily activities. Two thirds of people with BMS have a spontaneous partial recovery six to seven years after the initial onset, but in others the condition is permanent. Recovery is often preceded by a change in the character of the symptom from constant to intermittent. No clinical factors predicting recovery have been noted.

If there is an identifiable cause for the burning sensation (i.e. primary BMS), then psychologic dysfunctions such as anxiety and depression often disappear if the symptom is successfully treated.

Treatment of mucositis is mainly supportive. Oral hygiene is the mainstay of treatment; patients are encouraged to clean their mouth every four hours and at bedtime, more often if the mucositis becomes worse.

Water-soluble jellies can be used to lubricate the mouth. Salt mouthwash can soothe the pain and keep food particles clear so as to avoid infection. Patients are also encouraged to drink plenty of liquids, at least three liters a day, and avoid alcohol. Citrus fruits, alcohol, and foods that are hot are all known to aggravate mucositis lesions. Medicinal mouthwashes may be used such as Chlorhexidine gluconate and viscous Lidocaine for relief of pain. Palifermin is a human KGF (keratinocyte growth factor) that has shown to enhance epithelial cell proliferation, differentiation, and migration. Experimental therapies have been reported, including the use of cytokines and other modifiers of inflammation (e.g., IL-1, IL-11, TGF-beta3), amino acid supplementation (e.g., glutamine), vitamins, colony-stimulating factors, cryotherapy, and laser therapy.

Symptomatic relief of the pain of oral mucositis may be provided by barrier protection agents such as concentrated oral gel products (e.g. Gelclair). Caphosol is a mouth rinse which has been shown to prevent and treat oral mucositis caused by radiation and high-dose chemotherapy. MuGard is a FDA-cleared mucoadhesive oral protectant, developed by Access Pharmaceuticals, Inc., that is designed to form a protective hydrogel coating over the oral mucosa while a patient is undergoing chemotherapy and/or radiotherapy cancer treatments to the head and neck. Additionally, the efficacy of MuGard for the prevention or treatment of mucositis has been tested by a prospective, randomized clinical trial in which 43% of head and neck cancer patients using MuGard prophylactically never got oral mucositis.

NeutraSal is an FDA-cleared calcium phosphate mouth rinse which has been shown in an open-label, observational registry trial to prevent and reduce the severity of oral mucositis caused by radiation and high-dose chemotherapy. In the trial, 56% of the radiotherapy patients reported 0 (WHO score) or no mucositis, which is significantly lower than historical rates. Another super saturated calcium phosphate rinse on the market and cleared by the FDA is the US based SalivaMAX. The Mayo Clinic has been testing the antidepressant doxepin in a mouthwash to help treat symptoms.

In 2011, the FDA cleared episil oral liquid for the management and relief of pain of oral lesions with various etiologies, including oral mucositis/stomatitis which may be caused by chemotherapy or radiation therapy. The transformative mechanism of action of episil creates a lipid membrane that mechanically bonds to the oral cavity mucosa to coat and soothe inflammation and ulcerations, and blanket painful lesions. In a multicenter, randomized, double-blind, single-dose study involving 38 head and neck cancer patients with oral mucositis (WHO grades 2-3) undergoing radiation therapy, episil clinically demonstrated fast-acting relief that lasted up to 8 hours. Episil oral liquid is marketed in the US by Cangene.

In a 2012 randomized controlled pilot study involving pediatric patients, topical application of honey was found to reduce recovery time compared to benzocaine gel in grade 2 and 3 chemotherapy-induced oral mucositis to a degree that was statistically significant. In grade 3 oral mucositis, honey was as effective as a mixture of honey, olive oil and propolis, while both treatments were found to reduce recovery time compared to the benzocaine control.

Clinical research is ongoing in oral mucositis. A recent phase 2 exploratory trial in oral mucositis reported that dusquetide, a unique innate immune modulator with a mechanism that potentially addresses each of the phases of OM pathophysiology, is able to reduce the duration of severe oral mucositis, as well as reducing the incidence of infections. Dusquetide is being developed by Soligenix, Inc.

A 2015 Cochrane systematic review assessing the prevention of chemotherapy-induced oral mucositis concluded that oral cryotherapy leads to large reductions in the incidence of oral mucositis of all severities in adults receiving 5-FU treatment for solid cancers. The evidence also indicates a reduction of oral mucositis in adults receiving high-dose melphalan-based cancer treatment prior to haematopoietic stem cell transplantation, although there is uncertainty regarding the size of the reduction in this instance. No evidence was found for use of this preventive measure in children. Oral cryotherapy involves the placement of rounded ice chips in the mouth, which cools the oral tissues and causes vasoconstriction. This decreases blood flow to the region and, hence, also restricts the amounts of the chemotherapy drugs delivered to the tissues.

Aside from physiologic causes of xerostomia, iatrogenic effects of medications are the most common cause. A medication which is known to cause xerostomia may be termed "xerogenic". Over 500 medications produce xerostomia as a side effect (see table). Sixty-three percent of the top 200 most commonly prescribed drugs in the United States are xerogenic. The likelihood of xerostomia increases in relation to the total number of medications taken, whether the individual medications are xerogenic or not. The sensation of dryness usually starts shortly after starting the offending medication or after increasing the dose. Anticholinergic, sympathomimetic, or diuretic drugs are usually responsible.

When untreated, the prognosis for ORS is generally poor. It is chronic, lasting many years or even decades with worsening of symptoms rather than spontaneous remission. Transformation to another psychiatric condition is unlikely, although very rarely what appears to be ORS may later manifest into schizophrenia, psychosis, mania, or major depressive disorder. The most significant risk is suicide.

When treated, the prognosis is better. In one review, the proportion of treated ORS cases which reported various outcomes were assessed. On average, the patients were followed for 21 months (range: 2 weeks to 10 years). With treatment, 30% recovered (i.e. no longer experienced ORS odor beliefs and thoughts of reference), 37% improved and in 33% there was a deterioration in the condition (including suicide) or no change from the pre-treatment status.

Ageusia is the loss of taste, particularly the inability to detect sweetness, sourness, bitterness, saltiness, and umami (meaning "pleasant/savory taste"). It is sometimes confused with anosmia (a loss of the sense of smell). Because the tongue can only indicate texture and differentiate between sweet, sour, bitter, salty, and umami, most of what is perceived as the sense of taste is actually derived from smell. True ageusia is relatively rare compared to hypogeusia (a partial loss of taste) and dysgeusia (a distortion or alteration of taste).

Tissue damage to the nerves that support the tongue can cause ageusia, especially damage to the lingual nerve and the glossopharyngeal nerve. The lingual nerve passes taste for the front two-thirds of the tongue and the glossopharyngeal nerve passes taste for the back third of the tongue. The lingual nerve can also be damaged during otologic surgery, causing a feeling of metal taste.

Taste loss can vary from true aguesia, a complete loss of taste, to hypogeusia, a partial loss of taste, to dysgeusia, a distortion or alteration of taste. The primary cause of ageusia involves damage to the lingual nerve, which receives the stimuli from taste buds for the front two-thirds of the tongue, or the glossopharyngeal nerve, which acts similarly for the back third. Damage may be due to neurological disorders, such as Bell’s palsy or multiple sclerosis, as well as infectious diseases such as meningoencephalopathy. Other causes include a vitamin B deficiency, as well as taste bud death due to acidic/spicy foods, radiation, and/or tobacco use.

Degrees of vision loss vary dramatically, although the ICD-9 released in 1979 categorized them into three tiers: normal vision, low vision, and blindness. Two significant causes of vision loss due to sensory failures include media opacity and optic nerve diseases, although hypoxia and retinal disease can also lead to blindness. Most causes of vision loss can cause varying degrees of damage, from total blindness to a negligible effect. Media opacity occurs in the presence of opacities in the eye tissues or fluid, distorting and/or blocking the image prior to contact with the photoreceptor cells. Vision loss often results despite correctly functioning retinal receptors. Optic nerve diseases such as optic neuritis or retrobulbar neuritis lead to dysfunction in the afferent nerve pathway once the signal has been correctly transmitted from retinal photoreceptors.

Partial or total vision loss may affect every single area of a person's life. Though loss of eyesight may occur naturally as we age, trauma to the eye or exposure to hazardous conditions may also cause this serious condition. Workers in virtually any field may be at risk of sustaining eye injuries through trauma or exposure. A traumatic eye injury occurs when the eye itself sustains some form of trauma, whether a penetrating injury such as a laceration or a non-penetrating injury such as an impact. Because the eye is a delicate and complex organ, even a slight injury may have a temporary or permanent effect on eyesight.