Numerous compounds alleviate the pain from allodynia. Some are specific for certain types of allodynia while others are general. They include:

- Dynamic mechanical allodynia - compounds targeting different ion channels; opioids

- Mexiletine

- Lidocaine (IV/topical)

- Tramadol

- Morphine (IV)

- Alfentanil (IV)

- Ketamine (IV)

- Methylprednisone (intrathecal)

- Adenosine

- Glycine antagonist

- Desipramine

- Venlafaxine

- Lyrica

- Static mechanical allodynia - sodium channel blockers, opioids

- Lidocaine (IV)

- Alfentanil (IV)

- Adenosine (IV)

- Ketamine (IV)

- Glycine antagonist

- Venlafaxine

- Gabapentin (may also be helpful in cold and dynamic allodynias)

- Cold allodynia

- Lamotrigine

- Lidocaine (IV)

The list of compounds that can be used to treat allodynia is even longer than this. For example, many non-steroidal anti-inflammatory drugs, such as naproxen, can inhibit COX-1 and/or COX-2, thus preventing the sensitization of the central nervous system. Another effect of naproxen is the reduction of the responsiveness of mechano- and thermoreceptors to stimuli.

Other compounds act on molecules important for the transmission of an action potential from one neuron to another. Examples of these include interfering with receptors for neurotransmitters or the enzymes that remove neurotransmitters not bound to receptors.

Endocannabinoids are molecules that can relieve pain by modulating nociceptive neurons. When anandamide, an endocannabinoid, is released, pain sensation is reduced. Anandamide is later transported back to the neurons releasing it using transporter enzymes on the plasma membrane, eventually disinhibiting pain perception. However, this re-uptake can be blocked by AM404, elongating the duration of pain inhibition.

Hyperalgesia is similar to other sorts of pain associated with nerve irritation or damage such as allodynia and neuropathic pain, and consequently may respond to standard treatment for these conditions, using various drugs such as SSRI or tricyclic antidepressants, Nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, gabapentin or pregabalin, NMDA antagonists, or atypical opioids such as tramadol. Where hyperalgesia has been produced by chronic high doses of opioids, reducing the dose may result in improved pain management. However, as with other forms of nerve dysfunction associated pain, treatment of hyperalgesia can be clinically challenging, and finding a suitable drug or drug combination that is effective for a particular patient may require trial and error. The use of a transcutaneous electrical nerve stimulation device has been shown to alleviate hyperalgesia.

Tentative evidence supports the use of bisphosphonates, calcitonin, and ketamine. Doing nerve blocks with guanethidine appears to be harmful. Evidence for sympathetic nerve blocks generally is insufficient to support their use. Intramuscular botulinum injections may benefit people with symptoms localized to one extremity.

Ketamine, a dissociative anesthetic, appears promising as a treatment for complex regional pain syndrome. It may be used in low doses if other treatments have not worked. No benefit on either function or depression, however, has been seen.

Treatment of opioid tolerance and Opioid-Induced Hyperalgesia (OIH) differs but it may be difficult to differentiate these two conditions in a clinical setting where most pain assessments are done through simple scale scores. The treatment for OIH may be challenging because an inadequate number of quality studies exists possibly due to the complexity in diagnosis of OIH and challenges in working with patients on chronic opioids. Currently there is no single best treatment method for OIH and clinicians are advised to choose an appropriate therapy based on the unique clinical scenario and history of each patient.

One general treatment option is to reduce or discontinue the dose of opioid to see if OIH is improved. Opioid sparing or opioid switching, which is replacing the current opioid with another pharmacological agent such as morphine or methadone, has been reported to be effective in some studies but this may also increase the sensitivity to pain according to some case reports. Ketamine, a NMDA antagonist, has been shown to prevent the extended use of opioid in post-operative hyperalgesia when it is infused in a small amount perioperatively along with the opioid but there are also studies that show ketamine being ineffective in modulating hyperalgesia. Addition of the NSAID, especially some COX-2 inhibitors, or acetaminophen is also suggested as a possible treatment option.

Over-the-counter drugs, like acetaminophen, aspirin, or ibuprofen, can be effective but tend to only be helpful as a treatment for a few times in a week at most. Analgesic/sedative combinations are widely used (e.g., analgesic/antihistamine combinations like Syndol, Mersyndol and Percogesic, analgesic/barbiturate combinations such as Fiorinal). Frequent use of analgesics may, however, lead to medication overuse headache.

Botulinum toxin does not appear to be helpful.

People who have 15 or more headaches in a month may be treated with certain types of daily antidepressants which act to prevent continued tension headaches from occurring. In those who are predisposed to tension type headaches the first-line preventative treatment is amitriptyline, whereas mirtazapine and venlafaxine are second-line treatment options. Tricyclic antidepressants appear to be useful for prevention. Tricyclic antidepressants have been found to be more effective than SSRIs but have greater side effects. Evidence is poor for the use of SSRIs, propranolol, and muscle relaxants for prevention of tension headaches.

Traditional analgesics

The pain in Dercum's disease is often reported to be refractory to analgesics and to non-steroidal anti-inflammatory drugs (NSAIDs). However, this has been contradicted by the findings of Herbst et al. They reported that the pain diminished in 89% of patients (n=89) when treated with NSAIDs and in 97% of patients when treated with narcotic analgesics (n=37). The dosage required and the duration of the pain relief are not precisely stated in the article.

Lidocaine

An early report from 1934 showed that intralesional injections of procaine (Novocain®) relieved pain in six cases. More recently, other types of local treatment of painful sites with lidocaine patches (5%) (Lidoderm®) or lidocaine/prilocaine (25 mg/25 mg) cream (EMLA®) have shown a reduction of pain in a few cases.

In the 1980s, treatment with intravenous infusions of lidocaine (Xylocaine®) in varying doses was reported in nine patients. The resulting pain relief lasted from 10 hours to 12 months. In five of the cases, the lidocaine treatment was combined with mexiletine (Mexitil®), which is a class 1B anti-arrhythmic with similar pharmacological properties as lidocaine.

The mechanism by which lidocaine reduces pain in Dercum's disease is unclear. It may block impulse conduction in peripheral nerves, and thereby disconnect abnormal nervous impulse circuits. Nonetheless, it might also depress cerebral activity that could lead to increased pain thresholds. Iwane et al. performed an EEG during the administration of intravenous lidocaine. The EEG showed slow waves appearing 7 minutes after the start of the infusion and disappearing within 20 minutes after the end of the infusion. On the other hand, the pain relief effect was the greatest at about 20 minutes after the end of the infusion.

Based on this, the authors concluded that the effect of lidocaine on peripheral nerves most likely explains why the drug has an effect on pain in Dercum's disease. In contrast, Atkinson et al. have suggested that an effect on the central nervous system is more likely, as lidocaine can depress consciousness and decrease cerebral metabolism. In addition, Skagen et al. demonstrated that a patient with Dercum's disease lacked the vasoconstrictor response to arm and leg lowering, which indicated that the sympathicusmediated local veno-arteriolar reflex was absent. This could suggest increased sympathetic activity. An infusion of lidocaine increased blood flow in subcutaneous tissue and normalised the vasoconstrictor response when the limbs were lowered. The authors suggested that the pain relief was caused by a normalisation of up-regulated sympathetic activity.

Methotrexate and infliximab

One patient's symptoms were improved with methotrexate and infliximab. However, in another patient with Dercum's disease, the effect of methotrexate was discreet. The mechanism of action is unclear. Previously, methotrexate has been shown to reduce neuropathic pain caused by peripheral nerve injury in a study on rats. The mechanism in the rat study case was thought to be a decrease in microglial activation subsequent to nerve injury. Furthermore, a study has shown that infliximab reduces neuropathic pain in patients with central nervous system sarcoidosis. The mechanism is thought to be mediated by tumour necrosis factor inhibition.

Interferon α-2b

Two patients were successfully treated with interferon α-2b. The authors speculated on whether the mechanism could be the antiviral effect of the drug, the production of endogenous substances, such as endorphins, or interference with the production of interleukin-1 and tumour necrosis factor. Interleukin-1 and tumour necrosis factor are involved in cutaneous hyperalgesia.

Corticosteroids

A few patients noted some improvement when treated with systemic corticosteroids (prednisolone), whereas others experienced worsening of the pain. Weinberg et al. treated two patients with juxta-articular Dercum's disease with intralesional injections of methylprednisolone (Depo-Medrol). The patients experienced a dramatic improvement.

The mechanism for the pain-reducing ability of corticosteroids in some conditions is unknown. One theory is that they inhibit the effects of substances, such as histamine, serotonin, bradykinin, and prostaglandins. As the aetiology of Dercum's disease is probably not inflammatory, it is plausible that the improvement some of the patients experience when using corticosteroids is not caused by an anti-inflammatory effect.

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.

Hyperalgesia ( or ; 'hyper' from Greek ὑπέρ (huper, “over”), '-algesia' from Greek algos, ἄλγος (pain)) is an increased sensitivity to pain, which may be caused by damage to nociceptors or peripheral nerves. Prostaglandins E and F are largely responsible for sensitizing the nociceptors. Temporary increased sensitivity to pain also occurs as part of sickness behavior, the evolved response to infection.

Allodynia (Ancient Greek "" "állos" "other" and "" "odúnē" "pain") refers to central pain sensitization (increased response of neurons) following normally non-painful, often repetitive, stimulation. Allodynia can lead to the triggering of a pain response from stimuli which do not normally provoke pain. Temperature or physical stimuli can provoke allodynia, which may feel like a burning sensation, and it often occurs after injury to a site. Allodynia is different from hyperalgesia, an extreme, exaggerated reaction to a stimulus which is normally painful.

CVAC sessions

Cyclic Variations in Adaptive Conditioning (CVAC) is a method of touch free cyclic hypobaric pneumatic compression for treatment of tissue edema and, therefore, edema-associated pain. As a pilot study, 10 participants with AD completed pain and quality of life questionnaires before and after 20–40 minutes of CVAC process daily for 5 days. After treatment, there was a significant decrease in pain as measured by the Pain Catastrophizing Scale and the Visual Analogue Scale, but there was no change in pain quality by the McGill Pain Questionnaire. However, there were no changes in the Pain Disability Index or Pittsburgh Sleep Quality Index. This study suggests a potential treatment role for CVAC, and the authors recommended randomized controlled clinical trials.

In examining the published studies on opioid-induced hyperalgesia (OIH), Reznikov "et al" criticize the methodologies employed on both humans and animals as being far-removed from the typical regimen and dosages of pain patients in the real world. They also note that some OIH studies were performed on drug addicts in methadone rehabilitation programs, and that such results are very difficult to generalize and apply to medical patients in chronic pain. In contrast, a study of 224 chronic pain patients receiving 'commonly-used' doses of oral opioids, in more typical clinical scenarios, found that the opioid-treated patients actually experienced no difference in pain sensitivity when compared to patients on non-opioid treatments. The authors conclude that opioid-induced hyperalgesia may not be an issue of any significance for normal, medically-treated chronic pain patients at all.

Opioid-induced hyperalgesia has also been criticized as overdiagnosed among chronic pain patients, due to poor differential practice in distinguishing it from the much more common phenomenon of opioid tolerance. The misdiagnosis of common opioid tolerance (OT) as opioid-induced hyperalgesia (OIH) can be problematic as the clinical actions suggested by each condition can be contrary to each other. Patients misdiagnosed with OIH may have their opioid dose mistakenly decreased (in the attempt to counter OIH) at times when it is actually appropriate for their dose to be increased or rotated (as a counter to opioid tolerance).

The suggestion that chronic pain patients who are diagnosed as experiencing opioid-induced hyperalgesia ought to be completely withdrawn from opioid therapy has also been met with criticism. This is not only because of the uncertainties surrounding the diagnosis of OIH in the first place, but because of the viability of rotating the patient between different opioid analgesics over time. Opioid rotation is considered a valid alternative to the reduction or cessation of opioid therapy, and multiple studies demonstrate the rotation of opioids to be a safe and effective protocol.

Hyperpathia is a clinical symptom of certain neurological disorders wherein nociceptive stimuli evoke exaggerated levels of pain. This should not be confused with allodynia, where normally non-painful stimuli evoke pain.

A variety of over-the-counter and prescription anti-itch drugs are available. Some plant products have been found to be effective anti-pruritics, others not. Non-chemical remedies include cooling, warming, soft stimulation.

Topical antipruritics in the form of creams and sprays are often available over-the-counter. Oral anti-itch drugs also exist and are usually prescription drugs. The active ingredients usually belong to the following classes:

- Antihistamines, such as diphenhydramine (Benadryl)

- Corticosteroids, such as hydrocortisone topical cream; "see" topical steroid

- Counterirritants, such as mint oil, menthol, or camphor

- Crotamiton (trade name Eurax) is an antipruritic agent available as a cream or lotion, often used to treat scabies. Its mechanism of action remains unknown.

- Local anesthetics, such as benzocaine topical cream (Lanacane)

Phototherapy is helpful for severe itching, especially if caused by renal failure. The common type of light used is UVB.

Sometimes scratching relieves isolated itches, hence the existence of devices such as the back scratcher. Often, however, scratching can intensify itching and even cause further damage to the skin, dubbed the "itch-scratch-itch cycle."

The mainstay of therapy for dry skin is maintaining adequate skin moisture and topical emollients.

There are many causes of toothache and its diagnosis is a specialist topic, meaning that attendance at a dentist is usually required. Since many cases of toothache are inflammatory in nature, over the counter non-steroidal anti-inflammatory drugs (NSAIDs) may help (unless contraindicated, such as with a peptic ulcer). Generally, NSAIDs are as effective as aspirin alone or in combination with codeine. However, simple analgesics may have little effect on some causes of toothache, and the severe pain can drive individuals to exceed the maximum dose. For example, when acetaminophen (paracetamol) is taken for toothache, an accidental overdose is more likely to occur when compared to people who are taking acetaminophen for other reasons. Another risk in persons with toothache is a painful chemical burn of the oral mucosa caused by holding a caustic substance such as aspirin tablets and toothache remedies containing eugenol (such as clove oil) against the gum. Although the logic of placing a tablet against the painful tooth is understandable, an aspirin tablet needs to be swallowed to have any pain-killing effect. Caustic toothache remedies require careful application to the tooth only, without coming into excessive contact with the soft tissues of the mouth.

For the dentist, the goal of treatment generally is to relieve the pain, and wherever possible to preserve or restore function. The treatment depends on the cause of the toothache, and frequently a clinical decision regarding the current state and long-term prognosis of the affected tooth, as well as the individual's wishes and ability to cope with dental treatment, will influence the treatment choice. Often, administration of an intra-oral local anesthetic such as lidocaine and epinephrine is indicated in order to carry out pain-free treatment. Treatment may range from simple advice, removal of dental decay with a dental drill and subsequent placement of a filling, to root canal treatment, tooth extraction, or debridement.

Hyperpathia describes the neuropathic pain which the pain threshold on one hand is elevated and the other hand is central hyperexcited whenever there is a loss of fibres. Hyperpathia is underlying the peripheral or central deafferentation when the afferent inputs are lost. Hyperpathia only occurs on neuropathic pain patients with the loss of fibres.

The International Association of the Study of Pain’s (IASP) definition of hyperpathia is that: "A painful syndrome characterized by an abnormally painful reaction to a stimulus, "especially a repetitive stimulus, as well as an increased threshold." The definition also complies with a note which is: "It may occur with allodynia, hyperesthesia, hyperalgesia, or dysesthesia. Faulty identification and localization of the stimulus, delay, radiating sensation, and after-sensation may be present, and the pain is often explosive in character. The changes in this note are the specification of allodynia and the inclusion of hyperalgesia explicitly. Previously hyperalgesia was implied, since hyperesthesia was mentioned in the previous note and hyperalgesia is a special case of hyperesthesia".

In-office treatments may be much more complex and they may include the application of dental sealants, having fillings put over the exposed root that is causing the sensitivity, or a recommendation to wear a specially made night guard or retainer if the problems are a result of teeth grinding.

Other possible treatments include fluorides are also used because they decrease permeability of dentin "in vitro". Also, potassium nitrate can be applied topically in an aqueous solution or an adhesive gel. Oxalate products are also used because they reduce dentin permeability and occlude tubules more consistently. However, while some studies have showed that oxalates reduced sensitivity, others reported that their effects did not differ significantly from those of a placebo. Nowadays, dentin hypersensitivity treatments use adhesives, which include varnishes, bonding agents and restorative materials because these materials offer improved desensitization.

Low-output lasers are also suggested for dentin hypersensitivity, including GaAlAs lasers and . They are thought to act by producing a transient reduction in action potential in C-fibers in the pulp, but Aδ-fibers are not affected.

In pulpitis, an important distinction in regard to treatment is whether the inflammation is reversible or irreversible. Treatment of reversible pulpitis is by removing or correcting the causative factor. Usually, the decay is removed, and a sedative dressing is used to encourage the pulp to return to a state of health, either as a base underneath a permanent filling or as a temporary filling intended to last for a period while the tooth is observed to see if pulpitis resolves. Irreversible pulpitis and its sequalae pulp necrosis and apical periodontitis require treatment with root canal therapy or tooth extraction, as the pulp acts as a nidus of infection, which will lead to a chronic infection if not removed. Generally, there is no difference in outcomes between whether the root canal treatment is completed in one or multiple appointments. The field of regenerative endodontics is now developing ways to clean the pulp chamber and regenerate the soft and hard tissues to either regrow or simulate pulp structure. This has proved especially helpful in children where the tooth root has not yet finished developing and root canal treatments have lower success rates.

Reversible/irreversible pulpitis is a distinct concept from whether the tooth is restorable or unrestorable, e.g. a tooth may only have reversible pulpitis, but has been structurally weakened by decay or trauma to the point that it is impossible to restore the tooth in the long term.

At-home treatments include desensitizing toothpastes or dentifrices, potassium salts, mouthwashes and chewing gums.

A variety of toothpastes are marketed for dentin hypersensitivity, including compounds such as strontium chloride, strontium acetate, arginine, calcium carbonate, hydroxyapatite and calcium sodium phosphosilicate. Desensitizing chewing gums and mouthwashes are also marketed.

Potassium-containing toothpastes are common; however, the mechanism by which they may reduce hypersensitivity is unclear. Animal research has demonstrated that potassium ions placed in deep dentin cavities cause nerve depolarization and prevent re-polarization. It is not known if this effect would occur with the twice-daily, transient and small increase in potassium ions in saliva that brushing with potassium-containing toothpaste creates. In individuals with dentin hypersensitivity associated with exposed root surfaces, brushing twice daily with toothpaste containing 5% potassium nitrate for six to eight weeks reduces reported sensitivity to tactile, thermal and air blast stimuli. However, meta analysis reported that these individuals' subjective report of sensitivity did not significantly change after six to eight weeks of using the potassium nitrate toothpaste.

Desensitizing toothpastes containing potassium nitrate have been used since the 1980s while toothpastes with potassium chloride or potassium citrate have been available since at least 2000. It is believed that potassium ions diffuse along the dentinal tubules to inactivate intradental nerves. However, , this has not been confirmed in intact human teeth and the desensitizing mechanism of potassium-containing toothpastes remains uncertain. Since 2000, several trials have shown that potassium-containing toothpastes can be effective in reducing dentin hypersensitivity, although rinsing the mouth after brushing may reduce their efficacy.

Studies have found that mouthwashes containing potassium salts and fluorides can reduce dentine hypersensitivity, although rarely to any significant degree. , no controlled study of the effects of chewing gum containing potassium chloride has been made, although it has been reported as significantly reducing dentine hypersensitivity.

Nano-hydroxyapatite (nano-HAp) is considered one of the most biocompatible and bioactive materials, and has gained wide acceptance in dentistry in recent years. An increasing number of reports have shown that nano-hydroxyapatite shares characteristics with the natural building blocks of enamel having the potential, due to its particle size, to occlude exposed dentinal tubules helping to reduce hypersensitivity and enhancing teeth remineralization.

For this reason, the number of toothpastes and mouthwashes that already incorporate nano-hydroxyapatite as a desensitizing agent is increasing.

The medical literature suggests a number of treatments that have been proven effective for specific cases of needle phobia, but provides very little guidance to predict which treatment may be effective for any specific case. The following are some of the treatments that have been shown to be effective in some specific cases.

- Ethyl Chloride Spray (and other freezing agents). Easily administered, but provides only superficial pain control.

- Jet Injectors. Jet Injectors work by introducing substances into the body through a jet of high pressure gas as opposed to by a needle. Though these eliminate the needle, some people report that they cause more pain. Also, they are only helpful in a very limited number of situations involving needles i.e. insulin and some inoculations.

- Iontophoresis. Iontophoresis drives anesthetic through the skin by using an electric current. It provides effective anesthesia, but is generally unavailable to consumers on the commercial market and some regard it as inconvenient to use.

- EMLA. EMLA is a topical anesthetic cream that is a eutectic mixture of lidocaine and prilocaine. It is a prescription cream in the United States, and is available without prescription in some other countries. Although not as effective as iontophoresis, since EMLA does not penetrate as deeply as iontophoresis-driven anesthetics, EMLA provides a simpler application than iontophoresis. EMLA penetrates much more deeply than ordinary topical anesthetics, and it works adequately for many individuals.

- Ametop. Ametop gel appears to be more effective than EMLA for eliminating pain during venepuncture.

- Lidocaine/tetracaine patch. A self-heating patch containing a eutectic mixture of lidocaine and tetracaine is available in several countries, and has been specifically approved by government agencies for use in needle procedures. The patch is sold under the trade name "Synera" in the United States and "Rapydan" in European Union. Each patch is packaged in an air-tight pouch. It begins to heat up slightly when the patch is removed from the packaging and exposed to the air. The patch requires 20 to 30 minutes to achieve full anesthetic effect. The Synera patch was approved by the United States Food and Drug Administration on 23 June 2005.

- Behavioral therapy. Effectiveness of this varies greatly depending on the person and the severity of the condition. There is some debate as to the effectiveness of behavioral treatments for specific phobias (like blood, injection, injury type phobias), though some data are available to support the efficacy of approaches like exposure therapy. Any therapy that endorses relaxation methods may be contraindicated for the treatment of fear of needles as this approach encourages a drop in blood pressure that only enhances the vasovagal reflex. In response to this, graded exposure approaches can include a coping component relying on applied tension as a way to prevent complications associated with the vasovagal response to specific blood, injury, injection type stimulus.

- Nitrous Oxide (Laughing Gas). This will provide sedation and reduce anxiety for the patient, along with some mild analgesic effects.

- Inhalation General Anesthesia. This will eliminate all pain and also all memory of any needle procedure. On the other hand, it is often regarded as a very extreme solution. It is not covered by insurance in most cases, and most physicians will not order it. It can be risky and expensive and may require a hospital stay.

- Benzodiazepines, such as diazepam (Valium) or lorazepam, may help alleviate the anxiety of needle phobics, according to Dr. James Hamilton. These medications have an onset of action within 5 to 15 minutes from ingestion. A relatively large oral dose may be necessary.

Anterior cutaneous nerve entrapment syndrome (ACNES) is a nerve entrapment condition that causes chronic pain of the abdominal wall. It occurs when nerve endings of the lower thoracic intercostal nerves (7–12) are 'entrapped' in abdominal muscles, causing a severe localized nerve (neuropathic) pain that is usually experienced at the front of the abdomen.

ACNES syndrome is frequently overlooked and unrecognized, although the incidence is estimated to be 1:2000 patients.

The relative unfamiliarity with this condition often leads to significant diagnostic delays and misdiagnoses, often resulting in unnecessary diagnostic interventions and futile procedures. Physicians often misdiagnose ACNES as irritable bowel syndrome or "functional disorders", as symptoms of the condition are not dispositive.

Fear of needles, especially in its more severe forms, is often comorbid with other phobias and psychological ailments; for example, iatrophobia, or an irrational fear of doctors, is often seen in needle phobic patients.

A needle phobic patient does not need to physically be in a doctor's office to experience panic attacks or anxiety brought on by needle phobia. There are many triggers in the outside world that can bring on an attack through association. Some of these are blood, injuries, the sight of the needle physically or on a screen, paper pins, examination rooms, hospitals, white lab coats, hospital gowns, doctors, dentists, nurses, the antiseptic smell associated with offices and hospitals, the sight of a person who physically resembles the patient's regular health care provider, or even reading about the fear.

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.

Inflammation (from Latin "") is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair.

The classical signs of inflammation are heat, pain, redness, swelling, and loss of function. Inflammation is a generic response, and therefore it is considered as a mechanism of innate immunity, as compared to adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism. In contrast, chronic inflammation may lead to a host of diseases, such as hay fever, periodontitis, atherosclerosis, rheumatoid arthritis, and even cancer (e.g., gallbladder carcinoma). Inflammation is therefore normally closely regulated by the body.

Inflammation can be classified as either "acute" or "chronic". "Acute inflammation" is the initial response of the body to harmful stimuli and is achieved by the increased movement of plasma and leukocytes (especially granulocytes) from the blood into the injured tissues. A series of biochemical events propagates and matures the inflammatory response, involving the local vascular system, the immune system, and various cells within the injured tissue. Prolonged inflammation, known as "chronic inflammation", leads to a progressive shift in the type of cells present at the site of inflammation, such as mononuclear cells, and is characterized by simultaneous destruction and healing of the tissue from the inflammatory process.

Inflammation is not a synonym for infection. Infection describes the interaction between the action of microbial invasion and the reaction of the body's inflammatory response — the two components are considered together when discussing an infection, and the word is used to imply a microbial invasive cause for the observed inflammatory reaction. Inflammation on the other hand describes purely the body's immunovascular response, whatever the cause may be. But because of how often the two are correlated, words ending in the suffix "" (which refers to inflammation) are sometimes informally described as referring to infection. For example, the word "urethritis" strictly means only "urethral inflammation", but clinical health care providers usually discuss urethritis as a urethral infection because urethral microbial invasion is the most common cause of urethritis.

It is useful to differentiate inflammation and infection as there are many pathological situations where inflammation is not driven by microbial invasion – for example, atherosclerosis, type III hypersensitivity, trauma, ischaemia. There are also pathological situations where microbial invasion does not result in classic inflammatory response—for example, parasitosis, eosinophilia.