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.

If nonpharmacological methods are ineffective, medication may be necessary. As of 2013, no medication has been approved by the U.S. Food and Drug Administration to treat POTS, but a variety are used off-label. Their efficacy has not yet been examined in long-term randomized controlled trials.

Fludrocortisone may be used to enhance sodium retention and blood volume which may be beneficial not only by augmenting sympathetically-mediated vasoconstriction but also because a large subset of POTS patients appear to have low absolute blood volume.

While POTS patients typically have normal or even elevated arterial blood pressure, the neuropathic form of POTS is presumed to constitute a selective sympathetic venous denervation. In these patients the selective Alpha-1 Adrenergic receptor agonist Midodrine may increase venous return, enhance stroke volume and improve symptoms. Midodrine should only be taken during the daylight hours as it may promote supine hypertension.

Ivabradine can successfully restrain heart rate in POTS without affecting blood pressure and approximately 60% of POTS patients treated in an open-label trial of ivabradine experienced symptom improvement.

Pyridostigmine has been reported to restrain heart rate and improve chronic symptoms in about half of patients.

The selective alpha 1 agonist phenylephrine has been used successfully to enhance venous return and stroke volume in some people with POTS. However, this medication may be hampered by poor oral bioavailability.

The report of Da Costa shows that patients recovered from the more severe symptoms when removed from the strenuous activity or sustained lifestyle that caused them. A reclined position and forced bed rest was the most beneficial.

Other treatments evident from the previous studies were improving physique and posture, appropriate levels of exercise where possible, wearing loose clothing about the waist, and avoiding postural changes such as stooping, or lying on the left or right side, or the back in some cases, which relieved some of the palpitations and chest pains, and standing up slowly can prevent the faintness associated with postural or orthostatic hypotension in some cases.

Pharmacological intervention came in the form of digitalis, or "fox glove", which acts as a sodium-potassium ATPase inhibitor, increasing stroke volume and decreasing heart rate.

The treatment of dysautonomia can be difficult; since it is made up of many different symptoms, a combination of drug therapies is often required to manage individual symptomatic complaints. Therefore, if an autoimmune neuropathy is the case, then treatment with immunomodulatory therapies is done, or if diabetes mellitus is the cause, control of blood glucose is important. Treatment can include proton-pump inhibitors and H2 receptor antagonists used for digestive symptoms such as acid reflux.

For the treatment of genitourinary autonomic neuropathy medications may include sildenafil (a guanine monophosphate type-5 phosphodiesterase inhibitor). For the treatment of hyperhidrosis, anticholinergic agents such as trihexyphenidyl or scopolamine can be used, also intracutaneous injection of botulinum toxin type A can be used for management in some cases.

Balloon angioplasty, a procedure referred to as transvascular autonomic modulation, is specifically not approved for the treatment of autonomic dysfunction.

The prognosis of dysautonomia depends on several factors; individuals with chronic, progressive, generalized dysautonomia in the setting of central nervous system degeneration such as Parkinson's disease or multiple system atrophy have a generally poorer long-term prognosis. Consequently, dysautonomia could be fatal due to pneumonia, acute respiratory failure, or sudden cardiopulmonary arrest.

Autonomic dysfunction symptoms such as orthostatic hypotension, gastroparesis, and gustatory sweating are more frequently identified in mortalities.

The treatment for auto-brewery syndrome is a change in diet requiring low carbohydrates and high protein. Sugar is fermented into alcohol, and a diet that effectively lowers sugars also lowers the alcohol that can be fermented from it. Anything that causes an imbalance between the beneficial and harmful bacteria in the gut can help increase the chance that fermentation in the gut will develop. This can include not only antibiotics, but also overindulgence in sugars and carbohydrates. Watching what you eat could lower the risk of gut fermentation syndrome, and taking probiotics could further protect you by increasing the number of good bacteria in your system.

Treatment may involve investigation, reassurance and explanation, and possibly specialist treatment such as antidepressants or cognitive behavioral therapy.

Da Costa's syndrome, which was colloquially known as soldier's heart, is a syndrome with a set of symptoms that are similar to those of heart disease, though a physical examination does not reveal any physiological abnormalities. In modern times, Da Costa's syndrome is considered the manifestation of an anxiety disorder, and treatment is primarily behavioral, involving modifications to lifestyle and exercise.

The condition was named after Jacob Mendes Da Costa, who investigated and described the disorder during the American Civil War. It is also variously known as cardiac neurosis, chronic asthenia, effort syndrome, functional cardiovascular disease, neurocirculatory asthenia, primary neurasthenia, subacute asthenia and irritable heart.

A 2014 meta-analysis of three small trials evaluating probiotics showed a slight improvement in management of chronic idiopathic constipation, but well-designed studies are necessary to know the true efficacy of probiotics in treating this condition.

Children with functional constipation often claim to lack the sensation of the urge to defecate, and may be conditioned to avoid doing so due to a previous painful experience. One retrospective study showed that these children did indeed have the urge to defecate using colonic manometry, and suggested behavioral modification as a treatment for functional constipation.

Investigational medications include cannabinoids and the 5-HT3 receptor antagonist tropisetron. Low quality evidence found an improvement in symptoms with a gluten free diet among those without celiac disease. A controlled study of guaifenesin failed to demonstrate any benefits from this treatment.

Approximately 3% of children have constipation, with girls and boys being equally affected. With constipation accounting for approximately 5% of general pediatrician visits and 25% of pediatric gastroenterologist visits, the symptom carries a significant financial impact upon the healthcare system. While it is difficult to assess an exact age at which constipation most commonly arises, children frequently suffer from constipation in conjunction with life-changes. Examples include: toilet training, starting or transferring to a new school, and changes in diet. Especially in infants, changes in formula or transitioning from breast milk to formula can cause constipation. Fortunately, the majority of constipation cases are not tied to a medical disease, and treatment can be focused on simply relieving the symptoms.

The six-week period after pregnancy is called the postpartum stage. During this time, women are at increased risk of being constipated. Multiple studies estimate the prevalence of constipation to be around 25% during the first 3 months. Constipation can cause discomfort for women, as they are still recovering from the delivery process especially if they have had a perineal tear or underwent an episiotomy. Risk factors that increase the risk of constipation in this population include:

- Damage to the levator ani muscles (pelvic floor muscles) during childbirth

- Forceps-assisted delivery

- Lengthy second stage of labor

- Delivering a large child

- Hemorrhoids

Hemorrhoids are common in pregnancy and also may get exacerbated when constipated. Anything that can cause pain with stooling (hemorrhoids, perineal tear, episiotomy) can lead to constipation because patients may withhold from having a bowel movement so as to avoid pain.

The pelvic floor muscles play an important role in helping pass a bowel movement. Injury to those muscles by some of the above risk factors (examples- delivering a large child, lengthy second stage of labor, forceps delivery) can result in constipation. Women sometimes get enemas during labor that can also alter bowel movements in the days after having given birth. However, there is insufficient evidence to make conclusions about the effectiveness and safety of laxatives in this group of people.

The effects of the disease can have profound effects on everyday life. As well, the recurring side effects of excessive belching, dizziness, dry mouth, hangovers, disorientation, irritable bowel syndrome, and chronic fatigue syndrome can lead to other health problems such as depression, anxiety and poor productivity in employment. The random state of intoxication can lead to personal difficulties, and the relative obscurity of the condition can also make it hard to seek treatment.

Functional somatic syndromes may occur in 6 to 36% of the population.

A 2007 review concluded that a period of nine months of growth hormone was required to reduce fibromyalgia symptoms and normalize IGF-1. A 2014 also found some evidence support its use. Sodium oxybate increases growth hormone production levels through increased slow-wave sleep patterns. However, this medication was not approved by the FDA for the indication for use in people with fibromyalgia due to the concern for abuse.

The muscle relaxants cyclobenzaprine, carisoprodol with acetaminophen and caffeine and tizanidine are sometimes used to treat fibromyalgia; however as of 2015 they are not approved for this use in the United States. The use of NSAIDs is not recommended as first line therapy.

Dopamine agonists (e.g. pramipexole and ropinirole) resulted in some improvement in a minority of people, but numerous side effects, including the onset of impulse control disorders like compulsive gambling and shopping, have led to concern about this approach.

There is some evidence that 5HT antagonists may be beneficial. Preliminary clinical data finds that low-dose naltrexone (LDN) may provide symptomatic improvement.

Very low quality evidence suggests quetiapine may be effective in fibromyalgia.

No high quality evidence exists that suggests synthetic cannabinoids help with fibromyalgia, and in general tolerability is poor.

Upper airway resistance syndrome or UARS is a common sleep disorder characterized by the narrowing of the airway that can cause disruptions to sleep. The primary symptoms include excessive fatigue and chronic insomnia. UARS can be diagnosed by polysomnography, and can be treated with lifestyle changes, dental devices, or CPAP therapy. UARS is similar to certain types of sleep apneas.

There is considerable research into the causes, diagnosis and treatments for FGIDs. Diet, microbiome, genetics, neuromuscular function and immunological response all interact. Heightened mast cell activation has been proposed to be a common factor among FGIDs, contributing to visceral hypersensitivity as well as epithelial, neuromuscular, and motility dysfunction.

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.

Treatment is primarily through diet. Dietary fiber and fat can be increased and fluid intake, especially fruit juice intake, decreased. With these considerations, the patient should consume a normal balanced diet to avoid malnutrition or growth restriction. Medications such as loperamide should not be used. Studies have shown that certain probiotic preparations such as "Lactobacillus rhamnosus" (a bacterium) and "Saccharomyces boulardii" (a yeast) may be effective at reducing symptoms.

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.

This syndrome is predominantly found in young women, but also occurs in children, teenagers and octogenarians.

Major changes in the management of daytime wetting came about in the 1990s. In most current programs, non-invasive treatments incorporate hydration, timed voiding, correction of constipation and in some cases, computer assisted pelvic floor retraining. These methods have been extremely successful in correcting daytime wetting. Bladder stretching exercises (where the person tries to hold their urine as long as possible) are no longer recommended. In fact, some urologists actually believe that this can be dangerous because the person could develop the long-term habit of tightening the urethral sphincter muscle, which can cause bladder or kidney problems. Urinating on a regular basis is much preferred.

Ruling out infections can also be a part of the differential.

Fructose and fructans are FODMAPs (fermentable oligo-, di- and mono-saccharides and polyols) known to cause gastrointestinal discomfort in susceptible individuals. A low FODMAP diet has widespread application for managing functional gastrointestinal disorders such as IBS.

Nasal steroids may be prescribed in order to ease nasal allergies and other obstructive nasal conditions that could cause UARS.

Treatment consists of several such anesthetic injections, sometimes combined with corticosteroids. Such an approach yields persistent pain relief in two-thirds of patients. This beneficial effect on pain has been demonstrated in a prospective double blind trial. The physical volume of the injection may also break apart the adhesions or fibrosis responsible for the entrapment symptoms.

Patients who do not respond to a stratagem of repetitive local trigger point injections can be offered a surgical approach. Terminal branches of an intercostal nerve are removed at the level of the anterior sheath of the rectus abdominal muscle ('anterior neurectomy'). Several larger series demonstrated a successful response in approximately two out of three patients, which was confirmed in another prospective double blind surgical trial: 73% of the patients who underwent a neurectomy were pain free, compared to 18% in the non-nerve resected group. Patients not responding to an anterior neurectomy, or those in whom the pain syndrome recurs after an initial pain free period (10%) may choose to undergo secondary surgery. This involves a repeated exploration combined with a posterior neurectomy. This procedure has been shown to be beneficial in 50% of cases.