There is no certain pharmacological treatment or cure for CFS although various drugs have been or are being investigated. A 2014 report prepared by the Agency for Healthcare Research and Quality stated that there are wide variations in patient management, that many receive a multifaceted approach to treatment, and that no medications have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of ME/CFS, although several have been used off label. The report concluded that although counseling and graded exercise therapy (GET) have shown some benefits, these interventions have not been studied fully enough to recommend them for all persons affected. The report expressed concern that GET appears to be associated with worsening symptoms in some.

The United States Centres for Disease Control and Prevention (CDC) guide for the management of CFS states that while there is no cure, a number of methods might improve symptoms. Treatment strategies for sleep problems, pain, (depression, stress, and anxiety) dizziness and lightheadedness (Orthostatic Intolerance), and memory and concentration problems are enumerated. Other useful topics mentioned that patients and doctors might discuss include; carefully monitoring and managing activity to avoid worsening of symptoms, counseling to cope with the impact the illness may have on quality of life, proper nutrition and nutritional supplements that may support better health, complementary therapies that might help increase energy or decrease pain.

The United Kingdom's National Institute for Health and Clinical Excellence (NICE) guideline directed toward clinicians, specifies the need for shared decision-making between the patient and healthcare professionals, and acknowledges the reality and impact of the condition and the symptoms. The NICE guideline covers illness management aspects of diet, sleep and sleep disorders, rest, relaxation, and pacing. Referral to specialist care for cognitive behavioural therapy, graded exercise therapy and activity management programmes are recommended to be offered as a choice to patients with mild or moderate CFS. In 2017 NICE announced it is to update its guidance for CFS.

In 2017, the U.S. Centers for Disease Control and Prevention recommended light exercises and stretching but not in the four hours before bed to help with sleep. Stretching and movement therapies are also recommended for pain. Previously, a 2014 National Institutes of Health report concluded that while GET could produce benefits, it may not yield improvement in quality of life and that because of this limitation, GET should not be considered as a primary treatment, but instead be used only as one component of a broader approach. The report also noted that a focus on exercise programs had discouraged patient participation in other types of physical activity, due to concerns of precipitating increased symptoms. A July 2016 addendum to this report recommended that the Oxford criteria not be used when studying ME/CFS. If studies based on the Oxford criteria were excluded, there would be insufficient evidence of the effectiveness of GET on any outcome.

A 2016 Cochrane review stated that exercise therapy could contribute to alleviation of some symptoms of CFS, especially fatigue. The Cochrane review also noted that research was inconclusive as to which, if any, type of exercise therapy was superior, and concluded that no evidence had been found suggesting that exercise therapy worsened outcomes. A 2015 review article determined that serious adverse effects, or harms, from exercise therapy were poorly reported in most studies, and determined there was insufficient evidence for a conclusion.

As with CBT, patient organisations have long criticised the use of exercise therapy, most notably GET, as a treatment for CFS. In 2012 the MEA commenced an extensive opinion survey of patients who had received GET. Based on the findings of this survey, in 2015 the MEA concluded that GET in its current delivered form should not be recommended as a primary intervention for persons with CFS.

Treatment is similar to treatment for benign fasciculation syndrome.

Carbamazepine therapy has been found to provide moderate reductions in symptoms.

A functional disorder is a medical condition that impairs the normal function of a bodily process, but where every part of the body looks completely normal under examination, dissection or even under a microscope. This stands in contrast to a structural disorder (in which some part of the body can be seen to be abnormal) or a psychosomatic disorder (in which symptoms are caused by psychological or psychiatric illness). Definitions vary somewhat between fields of medicine.

Generally, the mechanism that causes a functional disorder is unknown, poorly understood, or occasionally unimportant for treatment purposes. The brain or nerves are often believed to be involved. It is common that a person with one functional disorder will have others.

Whether a given medical condition is termed a "functional disorder" depends in part on the state of knowledge. Some diseases, including epilepsy, schizophrenia, and migraine headaches were once considered functional disorders, but are no longer generally classified that way.

Most patients experience an improvement of their symptoms, but for some, OI can be gravely disabling and can be progressive in nature, particularly if it is caused by an underlying condition which is deteriorating. The ways in which symptoms present themselves vary greatly from patient to patient; as a result, individualized treatment plans are necessary.

OI is treated both pharmacologically and non-pharmacologically. Treatment does not cure OI; rather, it controls symptoms.

Physicians who specialize in treating OI agree that the single most important treatment is drinking more than two liters (eight cups) of fluids each day. A steady, large supply of water or other fluids reduces most, and for some patients all, of the major symptoms of this condition. Typically, patients fare best when they drink a glass of water no less frequently than every two hours during the day, instead of drinking a large quantity of water at a single point in the day.

For most severe cases and some milder cases, a combination of medications are used. Individual responses to different medications vary widely, and a drug which dramatically improves one patient's symptoms may make another patient's symptoms much worse. Medications focus on three main issues:

Medications that increase blood volume:

- Fludrocortisone (Florinef)

- Erythropoietin

- Hormonal contraception

Medications that inhibit acetylcholinesterase:

- Pyridostigmine

Medications that improve vasoconstriction:

- Stimulants: (e.g., Ritalin or Dexedrine)

- Midodrine (ProAmatine)

- Ephedrine and pseudoephedrine (Sudafed)

- Theophylline (low-dose)

- Selective serotonin reuptake inhibitors (SSRI's - Prozac, Zoloft, and Paxil)

Behavioral changes that patients with OI can make are:

- Avoiding triggers such as prolonged sitting, quiet standing, warm environments, or vasodilating medications

- Using postural maneuvers and pressure garments

- Treating co-existing medical conditions

- Increasing fluid and salt intake

- Physical therapy and exercise unless contraindicated by an underlying condition such as chronic fatigue syndrome where traditional exercise can worsen the condition

Category III prostatitis may have no initial trigger other than anxiety, often with an element of OCD, panic disorder, or other anxiety-spectrum problem. This is theorized to leave the pelvic area in a sensitized condition resulting in a loop of muscle tension and heightened neurological feedback (neural pain wind-up). Current protocols largely focus on stretches to release overtensed muscles in the pelvic or anal area (commonly referred to as trigger points) including digital intrarectal massage, physical therapy to the area, and progressive relaxation therapy to reduce causative stress.

Aerobic exercise can help those sufferers who are not also suffering from chronic fatigue syndrome or whose symptoms are not exacerbated by exercise. Acupuncture has reportedly benefited some patients.

For chronic nonbacterial prostatitis (Cat III), also known as CP/CPPS, which makes up the majority of men diagnosed with "prostatitis", a treatment called the "Wise–Anderson Protocol" (aka the "Stanford Protocol"), has recently been published. This is a combination of:

- Medication (using tricyclic antidepressants and benzodiazepines)

- Psychological therapy (paradoxical relaxation, an advancement and adaptation, specifically for pelvic pain, of a type of progressive relaxation technique developed by Edmund Jacobson during the early 20th century)

- Physical therapy (trigger point release therapy on pelvic floor and abdominal muscles, and also yoga-type exercises with the aim of relaxing pelvic floor and abdominal muscles).

Biofeedback physical therapy to relearn how to control pelvic floor muscles may be useful. Biofeedback is satisfactory for treatment of chronic prostatitis (with mainly voiding problems) during puberty.

A number of medications can be used to treat this disorder. Alpha blockers and/or antibiotics appear to be the most effective with NSAIDs such as ibuprofen providing lesser benefit.

- Treatment with antibiotics is controversial. Some have found benefits in symptoms while others have questioned the utility of a trial of antibiotics. Antibiotics are known to have anti-inflammatory properties and this has been suggested as an explanation for their partial efficacy in treating CPPS. Antibiotics such as fluoroquinolones, tetracyclines, and macrolides have direct anti-inflammatory properties in the absence of infection, blocking inflammatory chemical signals (cytokines) such as interleukin-1 (IL-1), interleukin-8 and tumor necrosis factor (TNF), which coincidentally are the same cytokines found to be elevated in the semen and EPS of men with chronic prostatitis.

- The effectiveness of alpha blockers (tamsulosin, alfuzosin) is questionable in men with CPPS. A 2006 meta-analysis found that they are moderately beneficial when the duration of therapy was at least 3 months.

- An estrogen reabsorption inhibitor such as mepartricin improves voiding, reduces urological pain and improves quality of life in patients with chronic non-bacterial prostatitis.

- Therapies that have not been properly evaluated in clinical trials although there is supportive anecdotal evidence include gabapentin, benzodiazepines, and amitriptyline.

Cramp fasciculation syndrome (CFS) is a rare peripheral nerve hyperexcitability disorder. It is more severe than the related (and common) disorder known as benign fasciculation syndrome; it causes fasciculations, cramps, pain, fatigue, and muscle stiffness similar to those seen in neuromyotonia (another related condition). Patients with CFS, like those with neuromyotonia, may also experience paresthesias.

Most cases of cramp fasciculation syndrome are idiopathic.

Cramp fasciculation syndrome is diagnosed by clinical examination and electromyography (EMG). Fasciculation is the only abnormality (if any) seen with EMG.

Cramp fasciculation syndrome is a chronic condition. Treatment options include anti-seizure medications such as carbamazepine, immunosuppressive drugs and plasmapheresis.

Symptoms of OI are triggered by the following:

- An upright posture for long periods of time (e.g. standing in line, standing in a shower, or even sitting at a desk).

- A warm environment (such as in hot summer weather, a hot crowded room, a hot shower or bath, after exercise).

- Emotionally stressful events (seeing blood or gory scenes, being scared or anxious).

- Astronauts returning from space not yet re-adapted to gravity.

- Extended bedrest

- Inadequate fluid and salt intake.

A Low FODMAP diet now has an evidence base sufficiently strong to recommend its widespread application in conditions such as IBS and IBD. Restriction of Fermentable Oligo-, Di- and Mono-

saccharides and Polyols globally, rather than individually, controls the symptoms of functional gut disorders (e.g. IBS), and the majority of IBD patients respond just as well. It is more successful than restricting only Fructose and Fructans, which are also FODMAPs, as is recommended for those with Fructose malabsorption. Longer term compliance with the diet was high.

A randomised controlled trial on IBS patients found relaxing an IgG-mediated food intolerance diet led to a 24% greater deterioration in symptoms compared to those on the elimination diet and concluded food elimination based on IgG antibodies may be effective in reducing IBS symptoms and is worthy of further biomedical research.

Intestinal or bowel hyperpermeability, so called leaky gut, has been linked to food allergies and some food intolerances. Research is currently focussing on specific conditions and effects of certain food constituents. At present there are a number of ways to limit the increased permeability, but additional studies are required to assess if this approach reduces the prevalence and severity of specific conditions.

Current research at the University of Utah is investigating whether sodium oxybate, also known as Gamma-Hydroxybutyric acid is an effective treatment for AHC. Thus far, only a small number of patients have been sampled, and no conclusive results are yet available. While some success has been had thus far with the drug, AHC patients have been known to respond well initially to other drugs, but then the effectiveness will decline over time. Currently, sodium oxybate is used as a narcolepsy-cataplexy treatment, though in the past it has been used controversially in nutritional supplements. This drug was chosen to test because of a possible link between the causes of narcolepsy-cataplexy and AHC.

Hemiplegic attacks can be brought on by particular triggers, and management of AHC often centers around avoiding common or known triggers. While triggers vary greatly from person to person, there are also some common ones which are prevalent in many patients. Common triggers include temperature changes, water exposure, bright lights, certain foods, emotional stress, and physical activity. While avoiding triggers may help, it cannot prevent all hemiplegic episodes because many occur without being triggered. Because attacks and other associated symptoms end with sleep, various sedatives can be used to help patients sleep.

POTS treatment involves using multiple methods in combination to counteract cardiovascular dysfunction, address symptoms, and simultaneously address any associated disorders. For most patients, water intake should be increased, especially after waking, in order to expand blood volume (reducing hypovolemia). 8–10 cups of water daily are recommended. Increasing salt intake, by adding salt to food, taking salt tablets, or drinking sports drinks and other electrolyte solutions is an effective way to raise blood pressure by helping the body retain water. Different physicians recommend different amounts of sodium to their patients. Salt intake is not appropriate for people with high blood pressure. Combining these techniques with gradual physical training enhances their effect. In some cases, when increasing oral fluids and salt intake is not enough, intravenous saline or the drug desmopressin is used to help increase fluid retention.

Large meals worsen symptoms for some people. These people may benefit from eating small meals frequently throughout the day instead. Alcohol and food high in carbohydrates can also exacerbate symptoms of orthostatic hypotension. Excessive consumption of caffeine beverages should be avoided, because they can promote urine production (leading to fluid loss) and consequently hypovolemia. Exposure to extreme heat may also aggravate symptoms.

Prolonged physical inactivity can worsen the symptoms of POTS. Techniques that increase a person's capacity for exercise, such as endurance training or graded exercise therapy, can relieve symptoms for some patients. Aerobic exercise performed for 20 minutes a day, three times a week, is sometimes recommended for patients who can tolerate it. Exercise may have the immediate effect of worsening tachycardia, especially after a meal or on a hot day. In these cases, it may be easier to exercise in a semi-reclined position, such as riding a recumbent bicycle, rowing or swimming.

When changing to an upright posture, finishing a meal or concluding exercise, a sustained hand grip can briefly raise the blood pressure, possibly reducing symptoms. Compression garments can also be of benefit by constricting blood pressures with external body pressure.

The prevalence of POTS is unknown. One study estimated a minimal rate of 170 POTS cases per 100,000 individuals, but the true prevalence is likely higher due to underdiagnosis. Another study estimated that there were between 500,000 and 3,000,000 cases in the United States. POTS is more common in women, with a female-to-male ratio of 5:1. Most people with POTS are aged between 20 and 40, with an average onset of 30. Diagnoses of POTS beyond age 40 are rare, perhaps because symptoms improve with age.

There is emerging evidence from studies of cord bloods that both sensitization and the acquisition of tolerance can begin in pregnancy, however the window of main danger for sensitization to foods extends prenatally, remaining most critical during early infancy when the immune system and intestinal tract are still maturing. There is no conclusive evidence to support the restriction of dairy intake in the maternal diet during pregnancy in order to prevent. This is generally not recommended since the drawbacks in terms of loss of nutrition can out-weigh the benefits. However, further randomised, controlled trials are required to examine if dietary exclusion by lactating mothers can truly minimize risk to a significant degree and if any reduction in risk is out-weighed by deleterious impacts on maternal nutrition.

A Cochrane review has concluded feeding with a soy formula cannot be recommended for prevention of allergy or food intolerance in infants. Further research may be warranted to determine the role of soy formulas for prevention of allergy or food intolerance in infants unable to be breast fed with a strong family history of allergy or cow's milk protein intolerance. In the case of allergy and celiac disease others recommend a dietary regimen is effective in the prevention of allergic diseases in high-risk infants, particularly in early infancy regarding food allergy and eczema. The most effective dietary regimen is exclusively breastfeeding for at least 4–6 months or, in absence of breast milk, formulas with documented reduced allergenicity for at least the first 4 months, combined with avoidance of solid food and cow's milk for the first 4 months.

There is no specific treatment for infectious mononucleosis, other than treating the symptoms. In severe cases, steroids such as corticosteroids may be used to control the swelling of the throat and tonsils. Currently, there are no antiviral drugs or vaccines available.

It is important to note that symptoms related to infectious mononucleosis caused by EBV infection seldom last for more than 4 months. When such an illness lasts more than 6 months, it is frequently called chronic EBV infection. However, valid laboratory evidence for continued active EBV infection is seldom found in these patients. The illness should be investigated further to determine if it meets the criteria for chronic fatigue syndrome, or CFS. This process includes ruling out other causes of chronic illness or fatigue.

Symptoms of infectious mononucleosis are fever, sore throat, and swollen lymph glands. Sometimes, a swollen spleen or liver involvement may develop. Heart problems or involvement of the central nervous system occurs only rarely, and infectious mononucleosis is almost never fatal. There are no known associations between active EBV infection and problems during pregnancy, such as miscarriages or birth defects. Although the symptoms of infectious mononucleosis usually resolve in 1 or 2 months, EBV remains dormant or latent in a few cells in the throat and blood for the rest of the person's life. Periodically, the virus can reactivate and is commonly found in the saliva of infected persons. Reactivated and post-latent virus may pass the placental barrier in (also seropositive) pregnant women via macrophages and therefore can infect the fetus. Also re-infection of prior seropositive individuals may occur. In contrast, reactivation in adults usually occurs without symptoms of illness.

EBV also establishes a lifelong dormant infection in some cells of the body's immune system. A late event in a very few carriers of this virus is the emergence of Burkitt's lymphoma and nasopharyngeal carcinoma, two rare cancers. EBV appears to play an important role in these malignancies, but is probably not the sole cause of disease.

Most individuals exposed to people with infectious mononucleosis have previously been infected with EBV and are not at risk for infectious mononucleosis. In addition, transmission of EBV requires intimate contact with the saliva (found in the mouth) of an infected person. Transmission of this virus through the air or blood does not normally occur. The incubation period, or the time from infection to appearance of symptoms, ranges from 4 to 6 weeks. Persons with infectious mononucleosis may be able to spread the infection to others for a period of weeks. However, no special precautions or isolation procedures are recommended, since the virus is also found frequently in the saliva of healthy people. In fact, many healthy people can carry and spread the virus intermittently for life. These people are usually the primary reservoir for person-to-person transmission. For this reason, transmission of the virus is almost impossible to prevent.

The clinical diagnosis of infectious mononucleosis is suggested on the basis of the symptoms of fever, sore throat, swollen lymph glands, and the age of the patient. Usually, laboratory tests are needed for confirmation. Serologic results for persons with infectious mononucleosis include an elevated white blood cell count, an increased percentage of certain atypical white blood cells, and a positive reaction to a "mono spot" test.

About half of people with SSNHL will recover some or all of their hearing spontaneously, usually within one to two weeks from onset. Eighty-five percent of those who receive treatment from an otolaryngologist (sometimes called an ENT) will recover some of their hearing.

- vitamins and antioxidants

- vasodilators

- betahistine (Betaserc), an anti-vertigo drug

- hyperbaric oxygen

- anti-inflammatory agents, primarily oral corticosteroids such as prednisone, methylprednisone

- Intratympanic administration - Gel formulations are under investigation to provide more consistent drug delivery to the inner ear. Local drug delivery can be accomplished through intratympanic administration, a minimally invasive procedure where the ear drum is anesthetized and a drug is administered into the middle ear. From the middle ear, a drug can diffuse across the round window membrane into the inner ear. Intratympanic administration of steroids may be effective for sudden sensorineural hearing loss for some patients, but high quality clinical data has not been generated. Intratympanic administration of an anti-apoptotic peptide (JNK inhibitor) is currently being evaluated in late-stage clinical development.

Hair cell regeneration using stem cell and gene therapy is years or decades away from being clinically feasible. However, studies are currently underway on the subject, with the first FDA-approved trial beginning in February 2012.

Fragile sites are associated with numerous disorders and diseases, both heritable and not. The FRAXA site is perhaps most famous for its role in Fragile X syndrome, but fragile sites are clinically implicated in many other important diseases, such as cancer.

A chromosomal fragile site is a specific heritable point on a chromosome that tends to form a gap or constriction and may tend to break when the cell is exposed to partial replication stress. Based on their frequency, fragile sites are classified as "common" or "rare". To date, more than 120 fragile sites have been identified in the human genome.

Common fragile sites are considered part of normal chromosome structure and are present in all (or nearly all) individuals in a population. Under normal conditions, most common fragile sites are not prone to spontaneous breaks. Common fragile sites are of interest in cancer studies because they are frequently affected in cancer and they can be found in healthy individuals. Sites FRA3B (harboring the "FHIT" gene) and FRA16D (harboring the "WWOX" gene) are two well known examples and have been a major focus of research.

Rare fragile sites are found in less than 5% of the population, and are often composed of two- or three-nucleotide repeats. They are often susceptible to spontaneous breakage during replication, frequently affecting neighboring genes. Clinically, the most important rare fragile site is FRAXA, which is associated with the fragile X syndrome, the most common cause of hereditary mental retardation.