According to the fourth revision of the "Diagnostic and Statistical Manual of Mental Disorders", phobias can be classified under the following general categories:

- Animal type – Fear of dogs, cats, rats and/or mice, pigs, cows, birds, spiders, or snakes.

- Natural environment type – Fear of water (aquaphobia), heights (acrophobia), lightning and thunderstorms (astraphobia), or aging (gerascophobia).

- Situational type – Fear of small confined spaces (claustrophobia), or the dark (nyctophobia).

- Blood/injection/injury type – this includes fear of medical procedures, including needles and injections (trypanophobia), fear of blood (hemophobia) and fear of getting injured.

- Other – children's fears of loud sounds or costumed characters.

As noted by Altman, McGoey & Sommer, it is important to observe the child, "in multiple contexts, on numerous occasions, and in their everyday environments (home, daycare, preschool)". It is beneficial to view parent and child interactions and behaviors that may contribute to SAD.

Dyadic Parent-Child Interaction Coding System and recently the Dyadic Parent-Child Interaction Coding System II (DPICS II) are methods used when observing parents and children interactions.

Separation Anxiety Daily Diaries (SADD) have also been used to “assess anxious behaviors along with their antecedents and consequences and may be particularly suited to SAD given its specific focus on parent–child separation” (Silverman & Ollendick, 2005). The diaries are carefully evaluated for validity.

At the preschool-aged stage, early identification and intervention is crucial. The communication abilities of young children are taken into consideration when creating age-appropriate assessments.

A commonly used assessment tool for preschool-aged children (ages 2–5) is the Preschool Age Psychiatric Assessment (PAPA). Additional questionnaires and rating scales that are used to assess the younger population include the Achenbach Scales, the Fear Survey Schedule for Infants and Preschoolers, and The Infant–Preschool Scale for Inhibited Behaviors.

Preschool children are also interviewed. Two interviews that are sometimes conducted are Attachment Doll-Play and Emotional Knowledge. In both of the assessments the interviewer depicts a scenario where separation and reunion occur; the child is then told to point at one of the four facial expressions presented. These facial expressions show emotions such as anger or sadness. The results are then analyzed.

Behavioral observations are also utilized when assessing the younger population. Observations enable the clinician to view some of the behaviors and emotions in specific contexts.

Main features of diagnostic criteria for specific phobia in the DSM-IV-TR:

- Marked and persistent fear that is excessive or unreasonable, cued by the presence or anticipation of a specific object or situation (e.g., flying, heights, animals, receiving an injection, seeing blood).

- Exposure to the phobic stimulus almost invariably provokes an immediate anxiety response, which may take the form of a situationally bound or situationally predisposed panic attack. In children, the anxiety may be expressed by crying, tantrums, freezing, or clinging.

- The person recognizes that the fear is excessive or unreasonable. In children, this feature may be absent.

- The phobic situation(s) is avoided or else is endured with intense anxiety or distress.

Specific Phobia – DSM 5 Criteria

- Fear or anxiety about a specific object or situation (In children fear/anxiety can be expressed by crying, tantrums, freezing, or clinging)

- The phobic object or situation almost always provokes immediate fear or anxiety

- The phobic object or situation is avoided or endured with intense fear or anxiety

- The fear or anxiety is out of proportion to the actual danger posed by the specific object or situation and to the sociocultural context

- The fear, anxiety, or avoidance is persistent, typically lasting for 6 months or more

- The fear, anxiety, or avoidance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning

- The disturbance is not better explained by symptoms of another mental disorder, including fear, anxiety, and avoidance of situations associated with panic-like symptoms or other incapacitating symptoms; objects or situations related to obsessions; reminders of traumatic events; separation from home or attachment figures; or social situations

Most people who present to mental health specialists develop agoraphobia after the onset of panic disorder. Agoraphobia is best understood as an adverse behavioral outcome of repeated panic attacks and subsequent anxiety and preoccupation with these attacks that leads to an avoidance of situations where a panic attack could occur. Early treatment of panic disorder can often prevent agoraphobia. Agoraphobia is typically determined when symptoms are worse than panic disorder, but also do not meet the criteria for other anxiety disorders such as depression. In rare cases where agoraphobics do not meet the criteria used to diagnose panic disorder, the formal diagnosis of agoraphobia without history of panic disorder is used (primary agoraphobia).

Autophobia is a form of anxiety that can cause a minor to extreme feeling of danger or fear when alone. There is not a specific treatment to cure autophobia as it affects each person differently. Most sufferers are treated with psychotherapy in which the amount of time that they are alone is slowly increased. There are no conclusive studies currently that support any medications being used as treatment. If the anxiety is too intense medications have been used to aid the patient in a continuation of the therapy.

It is not uncommon for sufferers to be unaware that they have this anxiety and to dismiss the idea of seeking help. Much like substance abuse, autophobia is mental and physical and requires assistance from a medical professional. Medication can be used to stabilize symptoms and inhibit further substance abuse. Group and individual therapy is used to help ease symptoms and treat the phobia.

In mild cases of autophobia, treatment can sometimes be very simple. Therapists recommend many different remedies to make patients feel as though they are not alone even when that is the case, such as listening to music when running errands alone or turning on the television when at home, even if it is just for background noise. Using noise to interrupt the silence of isolated situations can often be a great help for people suffering from autophobia.

However, it is important to remember that just because a person may feel alone at times does not mean that they have autophobia. Most people feel alone and secluded at times; this is not an unusual phenomenon. Only when the fear of being alone beings to interrupt how a person lives their daily life does the idea of being autophobic become a possibility.

Death anxiety is anxiety which is caused by thoughts of death. One source defines death anxiety as a "feeling of dread, apprehension or solicitude (anxiety) when one thinks of the process of dying, or ceasing to 'be'". It is also referred to as thanatophobia (fear of death), and is distinguished from necrophobia, which is a specific fear of dead or dying persons and/or things (i.e. others who are dead or dying, not one's own death or dying).

Additionally, there is anxiety caused by death-related thought-content, which might be classified within a clinical setting by a psychiatrist as morbid and/or abnormal, which for classification pre-necessitates a degree of anxiety which is persistent and interferes with everyday functioning. Lower ego integrity, more physical problems, and more psychological problems are predictive of higher levels of death anxiety in elderly people because of how close to death they are.

Certain children who are particularly attached to their mother or other family figure due to separation anxiety and/or attachment theory often suffer the onset early, in pre-school, crèche or before school starts.

School phobia is diagnosed primarily through questionnaires and interviews with doctors. Other methods like observation have not proven to be as useful. This is partly because (school) anxiety is an internal phenomenon. An example of a modern multidimensional questionnaire is the "Differential Power Anxiety Inventory 'approach, with twelve scales to diagnose four different areas: anxiety-inducing conditions, manifestations, coping strategies and stabilization forms."

- Cognitive and lifestyle exploration

- 'School Phobia Test' (SAT)

- 'Anxiety questionnaire for students', (AFS)

It is during the years of young adulthood (20 to 40 years of age) that death anxiety most often begins to become prevalent. However, during the next phase of life, the middle age adult years (40–64 years of age), death anxiety peaks at its highest levels when in comparison to all other age ranges throughout the lifespan. Surprisingly, levels of death anxiety then slump off in the old age years of adulthood (65 years of age and older). This is in contrast with most people’s expectations, especially regarding all of the negative connotations younger adults have about the elderly and the aging process (Kurlychek & Trenner, 1982).

DSM-5 diagnostic criteria for a panic attack include a discrete period of intense fear or discomfort, in which four (or more) of the following symptoms developed abruptly and reached a peak within minutes:

- Palpitations, and/or accelerated heart rate

- Sweating

- Trembling or shaking

- Sensations of shortness of breath or being smothered

- Feeling of choking

- Chest pain or discomfort

- Nausea or abdominal distress

- Feeling dizzy, unsteady, lightheaded, or faint

- Derealization (feelings of unreality) or depersonalization (being detached from oneself)

- Fear of losing control or going insane

- Sense of impending death

- Paresthesias (numbness or tingling sensations)

- Chills or hot flashes

In DSM-5, culture-specific symptoms (e.g., tinnitus, neck soreness, headache, and uncontrollable screaming or crying) may be seen. Such symptoms should not count as one of the four required symptoms.

Some or all of these symptoms can be found in the presence of a pheochromocytoma.

Screening tools such as the Panic Disorder Severity Scale can be used to detect possible cases of disorder and suggest the need for a formal diagnostic assessment.

ICD-10 defines social phobia as a fear of scrutiny by other people leading to avoidance of social situations. The anxiety symptoms may present as a complaint of blushing, hand tremor, nausea or urgency of micturition. Symptoms may progress to panic attacks.

Standardized rating scales such as the Social Phobia Inventory, the SPAI-B, Liebowitz Social Anxiety Scale, and the Social Interaction Anxiety Scale can be used to screen for social anxiety disorder and measure the severity of anxiety.

Dogs suffering from separation anxiety are often "owner addicts". Setting boundaries will boost a dog's confidence and prepare it to be on its own.

Various techniques have been suggested for helping dogs cope with separation anxiety:

- Leaving and returning home quietly, without fuss

- Providing plenty of exercise, play, and fun

- Practicing leaving to adjust the dog to your departure

- Feeding the dog before you leave

- Leaving the radio/TV on

- Medicating the dog

As of 2012, a San Diego cable channel is offering DOGTV, a cable-based television channel especially for dogs whose owners are away. The programming, created with the help of dog behavior specialists, is color-adjusted to appeal to dogs, and features 3–6 minute segments designed to relax, to stimulate, and to expose the dog to scenes of everyday life such as doorbells or riding in a vehicle. The channel's proponents have indicated positive reviews from a humane society shelter in Escondido, California. The "doggie resort" hosts of the opening party for Dog TV in San Diego reported that some of their dogs seem to enjoy watching the animated series "SpongeBob SquarePants". The show's creators anticipate that dogs will watch Dog TV intermittently, throughout the day, rather than remaining glued to the set.

Another technology based solution for calming separation anxious dogs is a software named Digital Dogsitter.

The user first records his or her voice to the software. When the dog is alone, the software listens to the dog and analyzes the incoming audio through the computer's microphone. Whenever the dog barks or howls, software plays the owner's voice to the dog, and the dog becomes calm.

The ICD-10 defines hypochondriasis as follows:

The DSM-IV defines hypochondriasis according to the following criteria:

A. Preoccupation with fears of having, or the idea that one has, a serious disease based on the person's misinterpretation of bodily symptoms.

B. The preoccupation persists despite appropriate medical evaluation and reassurance.

C. The belief in Criterion A is not of delusional intensity (as in Delusional Disorder, Somatic Type) and is not restricted to a circumscribed concern about appearance (as in Body Dysmorphic Disorder).

D. The preoccupation causes clinically significant distress or impairment in

social, occupational, or other important areas of functioning.

E. The duration of the disturbance is at least 6 months.

F. The preoccupation is not better accounted for by Generalized Anxiety Disorder, Obsessive-Compulsive Disorder, Panic Disorder, a Major Depressive Episode, Separation Anxiety, or another Somatoform Disorder.

The newly published DSM-5 replaces the diagnosis of hypochondriasis with "illness anxiety disorder".

Prevention of anxiety disorders is one focus of research. Use of CBT and related techniques may decrease the number of children with social anxiety disorder following completion of prevention programs.

Most research indicates that cognitive behavioral therapy (CBT) is an effective treatment for hypochondriasis. Much of this research is limited by methodological issues. A small amount of evidence suggests that selective serotonin reuptake inhibitors can also reduce symptoms, but further research is needed.

The diagnosis of an anxiety disorder requires first ruling out an underlying medical cause. Diseases that may present similar to an anxiety disorder, including certain endocrine diseases (hypo- and hyperthyroidism, hyperprolactinemia), metabolic disorders (diabetes), deficiency states (low levels of vitamin D, B2, B12, folic acid), gastrointestinal diseases (celiac disease, non-celiac gluten sensitivity, inflammatory bowel disease), heart diseases, blood diseases (anemia), and brain degenerative diseases (Parkinson's disease, dementia, multiple sclerosis, Huntington's disease).

Also, several drugs can cause or worsen anxiety, whether in intoxication, withdrawal, or from chronic use. These include alcohol, tobacco, cannabis, sedatives (including prescription benzodiazepines), opioids (including prescription pain killers and illicit drugs like heroin), stimulants (such as caffeine, cocaine and amphetamines), hallucinogens, and inhalants.

This method was developed in 1979 by interpreting the files of patients diagnosed with claustrophobia and by reading various scientific articles about the diagnosis of the disorder. Once an initial scale was developed, it was tested and sharpened by several experts in the field. Today, it consists of 20 questions that determine anxiety levels and desire to avoid certain situations. Several studies have proved this scale to be effective in claustrophobia diagnosis.

The most common adverse effects related to fluoxetine treatment were decreased appetite, experienced by 23% of the dogs in the study, and lethargy, experienced by 39% of the dogs in the study. Some canines actually experienced worsening anxiety and aggressive behavior.

In the study with clomipramine, 9 dogs underwent withdrawal after discontinuing treatment. 5 of those dogs were successful in overcoming the withdrawal, while 4 dogs relapsed. With regards to these results it is important to note that these sample sizes were relatively small. However, these studies have given us a look at one of the many variables regarding psychoactive drug withdrawal.

With regards to benzodiazepine treatment, it has been found that canines can develop dependence to these types of medications and go through a similar withdrawal process as humans. For example, their seizure threshold is lowered and anxiety relapse can occur after stopping benzodiazepine treatment. Similarly to treatment of human anxiety disorders, benzodiazepines are a last resort treatment, due to their addiction potential.

Autophobia, also called monophobia, isolophobia, or eremophobia, is the specific phobia of isolation; a morbid fear of being egotistical, or a dread of being alone or isolated. Sufferers need not be physically alone, but just to believe that they are being ignored or unloved. Contrary to what would be implied by a literal reading of the term, "autophobia" does not describe a "fear of oneself". The disorder typically develops from and is associated with other anxiety disorders.

Autophobia can be associated with or accompanied by several other phobias such as agoraphobia, and is generally considered to be a part of the agoraphobic cluster. This means that autophobia has a lot of the same characteristics as certain anxiety disorders and hyperventilation disorders. The main concern of people with phobias in the agoraphobic cluster is getting help in case of emergency. This means people might be afraid of going out in public, being caught in a crowd, being alone, or being stranded.

Autophobia is not to be confused with agoraphobia (fear of being in public, or caught in large crowds), self-hatred, or social anxiety although it can be closely related to these things. It is its own phobia that tends to be accompanied by other anxiety disorders and phobias.

Agoraphobia occurs about twice as commonly among women as it does in men. The gender difference may be attributable to several factors: sociocultural traditions that encourage, or permit, the greater expression of avoidance coping strategies by women (including dependent and helpless behaviors), women perhaps being more likely to seek help and therefore be diagnosed, and men being more likely to abuse alcohol in reaction to anxiety and be diagnosed as an alcoholic. Research has not yet produced a single clear explanation for the gender difference in agoraphobia.

Panic disorder with or without agoraphobia affects roughly 5.1% of Americans, and about 1/3 of this population with panic disorder have comorbid agoraphobia. It is uncommon to have agoraphobia without panic attacks, with only 0.17% of people with agorophobia not presenting panic disorders as well.

Approximately 1 to 5% of school-aged children have school refusal, though it is most common in 5- and 6-year olds and in 10- and 11-year olds, it occurs more frequently during major changes in a child’s life, such as entrance to kindergarten, changing from elementary to middle school, or changing from middle to high school. The problem may start following vacations, school holidays, summer vacation, or brief illness, after the child has been home for some time, and usually ends prior to vacations, school holidays, or summer vacation, before the child will be out of school for some time. School refusal can also occur after a stressful event, such as moving to a new house, or the death of a pet or relative.

The rate is similar within both genders, and although it is significantly more prevalent in some urban areas, there are no known socioeconomic differences.

The American Psychiatric Association introduced GAD as a diagnosis in the DSM-III in 1980, when anxiety neurosis was split into GAD and panic disorder. The definition in the DSM-III required uncontrollable and diffuse anxiety or worry that is excessive and unrealistic and persists for 1 month or longer. High rates in comorbidity of GAD and major depression led many commentators to suggest that GAD would be better conceptualized as an aspect of major depression instead of an independent disorder. Many critics stated that the diagnostic features of this disorder were not well established until the DSM-III-R. Since comorbidity of GAD and other disorders decreased with time, the DSM-III-R changed the time requirement for a GAD diagnosis to 6 months or longer. The DSM-IV changed the definition of "excessive worry" and the number of associated psychophysiological symptoms required for a diagnosis. Another aspect of the diagnosis the DSM-IV clarified was what constitutes a symptom as occurring "often". The DSM-IV also required difficulty controlling the worry to be diagnosed with GAD. The DSM-5 emphasized that excessive worrying had to occur more days than not and on a number of different topics. It has been stated that the constant changes in the diagnostic features of the disorder have made assessing epidemiological statistics such as prevalence and incidence difficult, as well as increasing the difficulty for researchers in identifying the biological and psychological underpinnings of the disorder. Consequently, making specialized medications for the disorder is more difficult as well. This has led to the continuation of GAD being medicated heavily with SSRIs.

This method was developed by Rachman and Taylor, two experts in the field, in 1993. This method is effective in distinguishing symptoms stemming from fear of suffocation and fear of restriction. In 2001, it was modified from 36 to 24 items by another group of field experts. This study has also been proven very effective by various studies.

The diagnostic criteria for GAD as defined by the Diagnostic and Statistical Manual of Mental Disorders DSM-5 (2013), published by the American Psychiatric Association, are paraphrased as follows:

No major changes to GAD have occurred since publication of the Diagnostic and Statistical Manual of Mental Disorders (2004); minor changes include wording of diagnostic criteria.

There are many ways to treat phobophobia, and the methods used to treat panic disorders have been shown to be effective to treat phobophobia, because panic disorder patients will present in a similar fashion to conventional phobics and perceive their fear as totally irrational. Also, exposure based techniques have formed the basis of the armamentarium of behaviour therapists in the treatment of phobic disorders for many years, they are the most effective forms of treatment for phobic avoidance behavior. Phobics are treated by exposing them to the stimuli which they specially fear, and in case of phobophobia, it is both the phobia they fear and their own sensations. There are two ways to approach interoceptive exposure on patients:

- Paradoxical intention: This method is especially useful to treat the fear towards the phobophobia and the phobia they fear, as well as some of the sensations the patient fears. This method exposes the patient to the stimuli that causes the fear, which they avoid. The patient is directly exposed to it bringing them to experience the sensations that they fear, as well as the phobia. This exposure based technique helps the doctor by guiding the patient to encounter their fears and overcome them by feeling no danger around them.

- Symptoms artificially produced: This method is very useful to treat the fear towards the sensations encountered when experiencing phobophobia, the main feared stimuli of this anxiety disorder. By ingestion of different chemical agents, such as caffeine, CO-O or adrenalin, some of the symptoms the patient feels when encountering phobophobia and other anxiety disorders are triggered, such as hyperventilation, heart pounding, blurring of vision and paresthesia, which can lead to the controlling of the sensations by the patients. At first, panic attacks will be encountered, but eventually, as the study made by Doctor Griez and Van den Hout shows, the patient shows no fear to somatic sensations and panic attacks and eventually of the phobia feared.

Cognitive modification is another method that helps considerably to treat phobophobics. When treating the patients with the method, doctors correct some wrong information the patient might have about his disease, such as their catastrophic beliefs or imminent disaster by the feared phobia. Some doctors have even agreed that this is the most helpful component, since it has shown to be very effective especially if combined with other methods, like interoceptive exposure. The doctor seeks to convince patients that their symptoms do not signify danger or loss of control, for example, if combined with the interoceptive exposure, the doctor can show them that there is no unavoidable calamity and if the patient can keep themselves under control, they learn by themselves that there is no real threat and that it is just in their mind. Cognitive modification also seeks to correct other minor misconceptions, such as the belief that the individual will go crazy and may need to be "locked away forever" or that they will totally lose control and perhaps "run amok". Probably, the most difficult aspect of cognitive restructuring for the majority of the patients will simply be to identify their aberrant beliefs and approach them realistically.

Relaxation and breathing control techniques are used to produce the symptoms naturally. The somatic sensations, the feared stimuli of phobophobia, are sought to be controlled by the patient to reduce the effects of phobophobia. One of the major symptoms encountered is that of hyperventilation, which produce dizziness, faintness, etc. So, hyperventilation is induced in the patients in order to increase their CO levels that produce some of this symptoms. By teaching the patients to control this sensations by relaxing and controlling the way they breathe, this symptoms can be avoided and reduce phobophobia. This method is useful if combined with other methods, because alone it doesn't treat other main problems of phobophobia.