Over-the-counter and prescription medications are readily available, such as dimenhydrinate, scopolamine, meclizine, promethazine, cyclizine, and cinnarizine. Cinnarizine is not available in the United States, as it is not approved by the FDA. As these medications often have side effects, anyone involved in high-risk activities while at sea (such as SCUBA divers) must evaluate the risks versus the benefits. Promethazine is especially known to cause drowsiness, which is often counteracted by ephedrine in a combination known as "the Coast Guard cocktail.". There are special considerations to be aware of when the common anti-motion sickness medications are used in the military setting where performance must be maintained at a high level.

Scopolamine is effective and is sometimes used in the form of transdermal patches (1.5 mg) or as a newer tablet form (0.4 mg). The selection of a transdermal patch or scopolamine tablet is determined by a doctor after consideration of the patient's age, weight, and length of treatment time required.

Many pharmacological treatments which are effective for nausea and vomiting in some medical conditions may not be effective for motion sickness. For example, metoclopramide and prochlorperazine, although widely used for nausea, are ineffective for motion-sickness prevention and treatment. This is due to the physiology of the CNS vomiting centre and its inputs from the chemoreceptor trigger zone versus the inner ear. Sedating anti-histamine medications such as promethazine work quite well for motion sickness, although they can cause significant drowsiness.

Ginger root is commonly thought to be an effective anti-emetic, but it is ineffective in treating motion sickness.

As astronauts frequently have motion sickness, NASA has done extensive research on the causes and treatments for motion sickness. One very promising looking treatment is for the person suffering from motion sickness to wear LCD shutter glasses that create a stroboscopic vision of 4 Hz with a dwell of 10 milliseconds.

Medications that may alleviate the symptoms of airsickness include:

- meclozine

- dimenhydrinate

- diphenhydramine

- scopolamine (available in both patch and oral form).

Pilots who are susceptible to airsickness should not take anti-motion sickness medications (prescription or over-the-counter). These medications can make one drowsy or affect brain functions in other ways.

There are numerous alternative remedies for motion sickness. One such is ginger, but it is ineffective.

Some desensitization treatments produce short-term improvements in symptoms. Long-term treatment success has been elusive.

There have been a number of studies into using virtual reality therapy for acrophobia.

Many different types of medications are used in the treatment of phobias like fear of heights, including traditional anti-anxiety drugs such as benzodiazepines, and newer options like antidepressants and beta-blockers.

Many drugs taken to relieve typical symptoms of motion sickness (including nausea, dizziness, etc.) contain compounds that may exacerbate drowsiness. Antihistamines are commonly used to treat motion sickness; however, side effects include drowsiness and impaired cognitive abilities. Anticholinergics such as scopolamine have also proved effective against motion sickness, but may induce drowsiness. These treatments may be combined with stimulants to counteract typical motion-induced nausea and dizziness while also preventing sedation.

However, many stimulants possess addictive properties, which result in a high potential for substance abuse. Some stimulants also tend to interfere with normal sleep patterns. Modafinil has been studied as a possible treatment for the sopite syndrome that does not appear to have the same side effects of normal stimulants. Modafanil appears to be effective when taken in combination with anticholinergics such as scopolamine, but studies of Modafanil-only treatments for motion sickness remain inconclusive.

Space motion sickness is caused by changes in g-forces, which affect spatial orientation in humans. According to "Science Daily", "Gravity plays a major role in our spatial orientation. Changes in gravitational forces, such as the transition to weightlessness during a space voyage, influence our spatial orientation and require adaptation by many of the physiological processes in which our balance system plays a part. As long as this adaptation is incomplete, this can be coupled to motion sickness (nausea), visual illusions and disorientation."

Modern motion-sickness medications can counter space sickness but are rarely used because it is considered better to allow space travelers to adapt naturally over the first day or two than to suffer the drowsiness and other side effects of medication. However, transdermal dimenhydrinate anti-nausea patches are typically used whenever space suits are worn because vomiting into a space suit could be fatal, as it could obscure vision or block airflow. Space suits are generally worn during launch and landing by NASA crew members and always for extra-vehicular activities (EVAs). EVAs are consequently not usually scheduled for the first days of a mission to allow the crew to adapt, and transdermal dimenhydrinate patches are typically used as an additional backup measure.

Flight experience with the use of anti-anxiety medications like benzodiazepines or other relaxant/depressant drugs varies from person to person. Medication decreases the person's reflective function. Though this may reduce anxiety caused by inner conflict, reduced reflective function can cause the anxious flier to believe what they are afraid will happen is actually happening.

A double-blind clinical study at the Stanford University School of Medicine suggests that anti-anxiety medication can keep a person from becoming accustomed to flight. In the research, two flights were conducted. In the first flight, though patients given alprazolam (Xanax) reported less anxiety than those receiving a placebo, their measurable stress increased. The heart rate in the alprazolam group was 114 versus 105 beats per minute in the placebo group. Those who received alprazolam also had increased respiration rates (22.7 vs 18.3 breaths/min).

On the second flight, no medication was given. Seventy-one percent of those who received alprazolam on the first flight experienced panic as compared with only 29% of those who received a placebo on the first flight. This suggests that the participants who were not medicated on the first flight benefited from the experience via some degree of desensitization.

Typical pharmacologic therapy is 0.5 or 1.0 mg of alprazolam about an hour before every flight, with an additional 0.5-1.0 mg if anxiety remains high during the flight. The alternative is to advise patients not to take medication, but encourage them to fly without it, instructing them in the principles of self-exposure.

A number of antiemetics are effective and safe in pregnancy including: pyridoxine/doxylamine, antihistamines (such as diphenhydramine), metoclopramide, and phenothiazines (such as promethazine). With respect to effectiveness it is unknown if one is superior to another. In the United States and Canada, the doxylamine-pyridoxine combination (as Diclegis in US and Diclectin in Canada) is the only approved pregnancy category "A" prescription treatment for nausea and vomiting of pregnancy.

Ondansetron may be beneficial, but there are some concerns regarding an association with cleft palate, and there is little high quality data. Metoclopramide is also used and relatively well tolerated. Evidence for the use of corticosteroids is weak.

Simulator sickness is a subset of motion sickness that is typically experienced by pilots who undergo training for extended periods of time in flight simulators. Due to the spatial limitations imposed on these simulators, perceived discrepancies between the motion of the simulator and that of the vehicle can occur and lead to simulator sickness.

It is similar to motion sickness in many ways, but occurs in simulated environments and can be induced without actual motion. Symptoms of simulator sickness include discomfort, apathy, drowsiness, disorientation, fatigue, vomiting, and many more.

These symptoms can reduce the effectiveness of simulators in flight training and result in systematic consequences such as decreased simulator use, compromised training, ground safety, and flight safety. Pilots are less likely to want to repeat the experience in a simulator if they have suffered from simulator sickness and hence can reduce the number of potential users. It can also compromise training in two safety-critical ways:

1. It can distract the pilot during training sessions.

2. It can cause the pilot to adopt certain counterproductive behaviors to prevent symptoms from occurring.

Simulator sickness can also have post-training effects that can compromise safety after the simulator session, such as when the pilots drive away from the facility or fly while experiencing symptoms of simulator sickness.

There is a lack of good evidence to support the use of any particular intervention for morning sickness.

All cases of decompression sickness should be treated initially with 100% oxygen until hyperbaric oxygen therapy (100% oxygen delivered in a high-pressure chamber) can be provided. Mild cases of the "bends" and some skin symptoms may disappear during descent from high altitude; however, it is recommended that these cases still be evaluated. Neurological symptoms, pulmonary symptoms, and mottled or marbled skin lesions should be treated with hyperbaric oxygen therapy if seen within 10 to 14 days of development.

Recompression on air was shown to be an effective treatment for minor DCS symptoms by Keays in 1909. Evidence of the effectiveness of recompression therapy utilizing oxygen was first shown by Yarbrough and Behnke, and has since become the standard of care for treatment of DCS. Recompression is normally carried out in a recompression chamber. At a dive site, a riskier alternative is in-water recompression.

Oxygen first aid has been used as an emergency treatment for diving injuries for years. If given within the first four hours of surfacing, it increases the success of recompression therapy as well as decreasing the number of recompression treatments required. Most fully closed-circuit rebreathers can deliver sustained high concentrations of oxygen-rich breathing gas and could be used as a means of supplying oxygen if dedicated equipment is not available.

It is beneficial to give fluids, as this helps reduce dehydration. It is no longer recommended to administer aspirin, unless advised to do so by medical personnel, as analgesics may mask symptoms. People should be made comfortable and placed in the supine position (horizontal), or the recovery position if vomiting occurs. In the past, both the Trendelenburg position and the left lateral decubitus position (Durant's maneuver) have been suggested as beneficial where air emboli are suspected, but are no longer recommended for extended periods, owing to concerns regarding cerebral edema.

The duration of recompression treatment depends on the severity of symptoms, the dive history, the type of recompression therapy used and the patient's response to the treatment. One of the more frequently used treatment schedules is the US Navy Table 6, which provides hyperbaric oxygen therapy with a maximum pressure equivalent to of seawater for a total time under pressure of 288 minutes, of which 240 minutes are on oxygen and the balance are air breaks to minimise the possibility of oxygen toxicity.

A multiplace chamber is the preferred facility for treatment of decompression sickness as it allows direct physical access to the patient by medical personnel, but monoplace chambers are more widely available and should be used for treatment if a multiplace chamber is not available or transportation would cause significant delay in treatment, as the interval between onset of symptoms and recompression is important to the quality of recovery. It may be necessary to modify the optimum treatment schedule to allow use of a monoplace chamber, but this is usually better than delaying treatment. A US Navy treatment table 5 can be safely performed without air breaks if a built-in breathing system is not available. In most cases the patient can be adequately treated in a monoplace chamber at the receiving hospital.

Space adaptation syndrome (SAS) or space sickness is a condition experienced by around half of space travelers during adaptation to weightlessness. It is related to motion sickness, as the vestibular system adapts to weightlessness.

This method forces patients to face their fears by complete exposure to whatever fear they are experiencing. This is usually done in a progressive manner starting with lesser exposures and moving upward towards severe exposures. For example, a claustrophobic patient would start by going into an elevator and work up to an MRI. Several studies have proven this to be an effective method in combating various phobias, claustrophobia included. S.J. Rachman has also tested the effectiveness of this method in treating claustrophobia and found it to decrease fear and negative thoughts/connotations by an average of nearly 75% in his patients. Of the methods he tested in this particular study, this was by far the most significant reduction.

The fear of spiders can be treated by any of the general techniques suggested for specific phobias. The first line of treatment is systematic desensitization – also known as exposure therapy – which was first described by South African psychiatrist Joseph Wolpe. Before engaging in systematic desensitization it is common to train the individual with arachnophobia in relaxation techniques, which will help keep the patient calm. Systematic desensitization can be done in vivo (with live spiders) or by getting the individual to imagine situations involving spiders, then modelling interaction with spiders for the person affected and eventually interacting with real spiders. This technique can be effective in just one session.

Recent advances in technology have enabled the use of virtual or augmented reality spiders for use in therapy. These techniques have proven to be effective.

Cognitive therapy is a widely accepted form of treatment for most anxiety disorders. It is also thought to be particularly effective in combating disorders where the patient doesn't actually fear a situation but, rather, fears what could result from being in such a situation. The ultimate goal of cognitive therapy is to modify distorted thoughts or misconceptions associated with whatever is being feared; the theory is that modifying these thoughts will decrease anxiety and avoidance of certain situations. For example, cognitive therapy would attempt to convince a claustrophobic patient that elevators are not dangerous but are, in fact, very useful in getting you where you would like to go faster. A study conducted by S.J. Rachman shows that cognitive therapy decreased fear and negative thoughts/connotations by an average of around 30% in claustrophobic patients tested, proving it to be a reasonably effective method.

The drug acetazolamide (trade name Diamox) may help some people making a rapid ascent to sleeping altitude above , and it may also be effective if started early in the course of AMS. Acetazolamide can be taken before symptoms appear as a preventive measure at a dose of 125 mg twice daily. The Everest Base Camp Medical Centre cautions against its routine use as a substitute for a reasonable ascent schedule, except where rapid ascent is forced by flying into high altitude locations or due to terrain considerations. The Centre suggests a dosage of 125 mg twice daily for prophylaxis, starting from 24 hours before ascending until a few days at the highest altitude or on descending; with 250 mg twice daily recommended for treatment of AMS. The Centers for Disease Control and Prevention (CDC) suggest the same dose for prevention of 125 mg acetazolamide every 12 hours. Acetazolamide, a mild diuretic, works by stimulating the kidneys to secrete more bicarbonate in the urine, thereby acidifying the blood. This change in pH stimulates the respiratory center to increase the depth and frequency of respiration, thus speeding the natural acclimatization process. An undesirable side-effect of acetazolamide is a reduction in aerobic endurance performance. Other minor side effects include a tingle-sensation in hands and feet. Although a sulfonamide; acetazolamide is a non-antibiotic and has not been shown to cause life-threatening allergic cross-reactivity in those with a self-reported sulfonamide allergy. Dosage of 1000 mg/day will produce a 25% decrease in performance, on top of the reduction due to high-altitude exposure. The CDC advises that Dexamethasone be reserved for treatment of severe AMS and HACE during descents, and notes that Nifedipine may prevent HAPE.

A single randomized controlled trial found that sumatriptan may help prevent altitude sickness. Despite their popularity, antioxidant treatments have not been found to be effective medications for prevention of AMS. Interest in phosphodiesterase inhibitors such as sildenafil has been limited by the possibility that these drugs might worsen the headache of mountain sickness. A promising possible preventive for altitude sickness is myo-inositol trispyrophosphate (ITPP), which increases the amount of oxygen released by hemoglobin.

Prior to the onset of altitude sickness, ibuprofen is a suggested non-steroidal anti-inflammatory and painkiller that can help alleviate both the headache and nausea associated with AMS. It has not been studied for the prevention of cerebral edema (swelling of the brain) associated with extreme symptoms of AMS.

For centuries, indigenous peoples of the Americas such as the Aymaras of the Altiplano, have chewed coca leaves to try to alleviate the symptoms of mild altitude sickness. In Chinese and Tibetan traditional medicine, an extract of the root tissue of "Radix rhodiola" is often taken in order to prevent the same symptoms, though neither of these therapies has been proven effective in clinical study.

The Simulator Sickness Questionnaire (SSQ) is currently the standard for measuring simulator sickness. The SSQ was developed based upon 1,119 pairs of pre-exposure/post-exposure scores from data that were collected and reported earlier. These data were collected from 10 Navy flight simulators representing both fixed-wing and rotary-wing aircraft. The simulators selected were both 6-DOF motion and fixed-base models, and also represented a variety of visual display technologies. The SSQ was developed and validated with data from pilots who reported to simulator training healthy and fit.

The SSQ is a self-report symptom checklist. It includes 16 symptoms that are associated with simulator sickness. Participants indicate the level of severity of the 16 symptoms that they are experiencing currently. For each of the 16 symptoms there are four levels of severity (none, slight, moderate, severe). The SSQ provides a Total Severity score as well as scores for three subscales (Nausea, Oculomotor, and Disorientation). The Total Severity score is a composite created from the three subscales. It is the best single measure because it provides an index of the overall symptoms. The three subscales provide diagnostic information about particular symptom categories:

- Nausea subscale is made up of symptoms such as increased salivation, sweating, nausea, stomach awareness, and burping.

- Oculomotor subscale includes symptoms such as fatigue, headache, eyestrain, and difficulty focusing.

- Disorientation subscale is composed of symptoms such as vertigo, dizzy (eyes open), dizzy (eyes closed), and blurred vision.

The three subscales are not orthogonal to one another. There is a general factor common to all of them. Nonetheless, the subscales provide differential information about participants' experience of symptoms and are useful for determining the particular pattern of discomfort produced by a given simulator. All scores have as their lowest level a natural zero (no symptoms) and increase with increasing symptoms reported.

The most common methods for the treatment of specific phobias are systematic desensitization and in vivo or exposure therapy.

In some cases, education can considerably diminish concern about physical safety. Learning how aircraft fly, how airliners are flown in practice, and other aspects of aviation can reduce anxiety. Many people have dealt with the problem by learning to fly or skydive, effectively removing their fear of the unknown. Some educate themselves; others attend courses offered by pilots or airlines.

Though education plays an important role, the knowledge that turbulence will not destroy the aircraft does not stop the amygdala - the part of the brain responsible for generating most emotional responses, and via the Hypothalamic–pituitary–adrenal axis, the release of stress hormones - from reacting. In turbulence, repeated downward movements of the plane trigger one release of stress hormones after another. A build-up of stress hormones can cause a person to be terrified despite having every reason to know logically that the plane is not in danger. In such cases, therapy — in addition to education — is needed to prevent the release of stress hormones so that the anxious flier may gain relief.

Behavioral therapies such as systematic desensitization developed by Joseph Wolpe and cognitive behavior therapy developed by Aaron Beck rest on the theory that an initial sensitizing event (ISE) has created the phobia. The gradually increased exposure needed for systematic desensitization is difficult to produce in actual flight. Desensitization using virtual flight has been disappointing. Clients report that simulated flight using computer-generated images does not desensitize them to risk because throughout the virtual flight they were aware they were in an office. Research shows Virtual Reality Exposure Therapy (VRET) to be no more effective than sitting on a parked airplane. As a practical substitute for systematic desensitization, the amygdala can be taught to regard a stimulus as benign by linking it to an experience already regarded by the amygdala as benign. This alternative has been termed systematic inhibition of the amygdala.

Hypnotherapy generally involves regression to the ISE, uncovering the event, the emotions around the event, and helping the client understand the source of their fear. It is sometimes the case that the ISE has nothing to do with flying at all.

Neurological research by Allan Schore and others using EEG-fMRI neuroimaging suggests that though it may first be manifest following a turbulent flight, fear of flying is not the result of a sensitizing event. The underlying problem is inadequate development of ability to regulate emotion when facing uncertainty, except through feeling in control or able to escape. According to Schore, the ability to adequately regulate emotion fails to develop when relationship with caregivers is not characterized by attunement and empathy. "Because these mothers are unable to regulate their own distress, they cannot regulate their infant's distress." Chronic stress and emotional dysregulation during the first two years of life inhibits development of the right prefrontal orbito cortex, and hinders the integration of the emotional control system. This renders the right prefrontal orbito cortex incapable of carrying out its executive role in the regulation of emotion. Some who disagree with the importance of early experience regard this view point as contentious. However, Harvard University and the National Scientific Council on the Developing Child state, "Genes provide the basic blueprint, but experiences influence how or whether genes are expressed. Together, they shape the quality of brain architecture and establish either a sturdy or a fragile foundation for all of the learning, health, and behavior that follow."

When it senses anything unfamiliar or unexpected, the amygdala releases stress hormones. In humans, stress hormones activate both the sympathetic nervous system and executive function. The sympathetic nervous system produces an urge to mobilize. Initially, to assess the situation, executive function overrides the urge to mobilize. If assessment reveals no threat, executive function dismisses the matter, and signals the amygdala to end stress hormone release. If risk is apparent, executive function considers what can be done to deal with the risk. Upon commitment to a plan, either of action or of inaction, executive function signals the amygdala to end stress hormone release.

In a non-phobic person, the arousal caused by the release of stress hormones results in a sense of curiosity, not a sense of emergency. Phobic response is significantly different. The phobic person equates arousal with fear, and fear as proof that there is danger. Upon arousal, the person's executive function is called upon not merely to assess the situation, but - if stress hormones are to be regulated - to prove no danger exists. If danger cannot be ruled out, executive function can no longer inhibit the urge to mobilize. Though phobics regard control as the antidote to fear, it is commitment to a plan - not control alone that ends the release of stress hormones. If a person has control but cannot commit to a plan, fear persists. It is interesting to note that commitment to any action - even unwise action - provides relief, and signals the amygdala to terminate stress hormone release.

If a phobic flier were able to fly in the cockpit, the pilot's facial response to an unexpected noise or motion would adequately prove the absence of danger. But with information in the cabin limited, it is impossible to prove no danger exists. Stress hormones continue to be released. As levels rise, anxiety increases and the urge to escape becomes paramount. Since physical escape is impossible, panic may result unless the person can escape psychologically through denial, dissociation, or distraction.

In the cognitive approach, the passenger learns to separate arousal from fear, and fear from danger. Cognitive therapy is most useful when there is no history of panic. But since in-flight panic develops rapidly, often through processes which the person has no awareness of, conscious measures may neither connect with - nor match the speed of - the unconscious processes that cause panic.

In another approach, emotion is regulated by what neuroscientist Stephen Porges calls neuroception. In social situations, arousal is powerfully regulated by signals people unconsciously send, receive, and process. For example, when encountering a stranger, stress hormone release increases the heart rate. But if the stranger's signals indicate trustworthiness, these signals override the effect of stress hormones, slow the heart, calm the person, and allow social interaction to take place. Because neuroception can completely override the effect of stress hormones, can be controlled by linking the noises and motions of flight to neuroceptive signals that calm the person.

Lastly, frequent flyer experts at Flightfox suggest that fear of flying is a reaction caused by the panic and tension of so many travellers in close quarters - once one person is uneasy the rest soon feel uncomfortable as well. Their solution, odd as it may seem, is to fly in premium class to experience flying in a comfortable and relaxed setting, so as to avoid the tension and anxiety of coach.

Antidepressant medications most commonly used to treat anxiety disorders are mainly selective serotonin reuptake inhibitors. Benzodiazepines, monoamine oxidase inhibitor, and tricyclic antidepressants are also sometimes prescribed for treatment of agoraphobia. Antidepressants are important because some have antipanic effects. Antidepressants should be used in conjunction with exposure as a form of self-help or with cognitive behaviour therapy. A combination of medication and cognitive behaviour therapy is sometimes the most effective treatment for agoraphobia.

Benzodiazepines, antianxiety medications such as alprazolam and clonazepam, are used to treat anxiety and can also help control the symptoms of a panic attack. If taken in doses larger than those prescribed, or for too long, they can cause dependence. Side effects may include confusion, drowsiness, light-headedness, loss of balance, and memory loss.

Immediate treatment with 100% oxygen, followed by recompression in a hyperbaric chamber, will in most cases result in no long-term effects. However, permanent long-term injury from DCS is possible. Three-month follow-ups on diving accidents reported to DAN in 1987 showed 14.3% of the 268 divers surveyed had ongoing symptoms of Type II DCS, and 7% from Type I DCS. Long-term follow-ups showed similar results, with 16% having permanent neurological sequelae.

Medications can help regulate the apprehension and fear that come from thinking about or being exposed to a particular fearful object or situation. Antidepressant medications such as SSRIs or MAOIs may be helpful in some cases of phobia. SSRIs (antidepressants) act on serotonin, a neurotransmitter in the brain. Since serotonin impacts mood, patients may be prescribed an antidepressant. Sedatives such as benzodiazepines may also be prescribed, which can help patients relax by reducing the amount of anxiety they feel. Benzodiazepines may be useful in acute treatment of severe symptoms, but the risk-benefit ratio is against their long-term use in phobic disorders. This class of medication has recently been shown as effective if used with negative behaviors such as alcohol abuse. Despite this positive finding, benzodiazepines should be used with caution. Beta blockers are another medicinal option as they may stop the stimulating effects of adrenaline, such as sweating, increased heart rate, elevated blood pressure, tremors and the feeling of a pounding heart. By taking beta blockers before a phobic event, these symptoms are decreased, causing the event to be less frightening.

The only reliable treatment, and in many cases the only option available, is to descend. Attempts to treat or stabilize the patient "in situ" (at altitude) are dangerous unless highly controlled and with good medical facilities. However, the following treatments have been used when the patient's location and circumstances permit:

- Oxygen may be used for mild to moderate AMS below and is commonly provided by physicians at mountain resorts. Symptoms abate in 12 to 36 hours without the need to descend.

- For more serious cases of AMS, or where rapid descent is impractical, a Gamow bag, a portable plastic hyperbaric chamber inflated with a foot pump, can be used to reduce the effective altitude by as much as . A Gamow bag is generally used only as an aid to evacuate severe AMS patients, not to treat them at altitude.

- Acetazolamide 250 mg twice daily dosing assists in AMS treatment by quickening altitude acclimatization. A study by the Denali Medical Research Project concluded: "In established cases of acute mountain sickness, treatment with acetazolamide relieves symptoms, improves arterial oxygenation, and prevents further impairment of pulmonary gas exchange."

- The folk remedy for altitude sickness in Ecuador, Peru and Bolivia is a tea made from the coca plant. See mate de coca.

- Steroids can be used to treat the symptoms of pulmonary or cerebral edema, but do not treat the underlying AMS.

- Two studies in 2012 showed that Ibuprofen 600 milligrams three times daily was effective at decreasing the severity and incidence of AMS; it was not clear if HAPE or HACE was affected.