Preventive analgesia is a practice aimed at reducing short- and long-term post-surgery pain. Activity in the body's pain signalling system during surgery produces "sensitization"; that is, it increases the intensity of post-operative pain. Reducing activity in the body's pain-signalling system by the use of analgesics before, during and immediately after surgery is thought to reduce subsequent sensitization, and consequently the intensity of post-surgery pain. The types of nerve activity targeted in preventive analgesia include pre-surgery pain, all pain-system activity caused during surgery, and pain produced post-surgery by damage and inflammation.

A person's assessment of pain intensity from standard experimental stimuli prior to surgery is correlated with the intensity of their post-surgery pain. Pain intensity immediately post-surgery

is correlated with pain intensity on release from hospital, and correlated with the likelihood of experiencing chronic post-surgery pain.

Different medications such as pregabalin, acetaminophen, naproxen and dextromethorphan have been tried in studies about preemptive analgesia. It is not known what causes some cases of acute post-surgery pain to become chronic long term problems but pain intensity in the short- and long-term post-operative period is correlated with the amount of pain system activity during and around the time of the surgery. It is not known whether reducing post-operative sensitization by the use of preventive analgesia will affect the likelihood of acute post-operative pain becoming chronic.

Electroanalgesia is a form of analgesia, or pain relief, that uses electricity to ease pain. Electrical devices can be internal or external, at the site of pain (local) or delocalized throughout the whole body. It works by interfering with the electric currents of pain signals, inhibiting them from reaching the brain and inducing a response; different from traditional analgesics, such as opiates which mimic natural endorphins and NSAIDS (non-steroidal anti-inflammatory drugs) that help relieve inflammation and stop pain at the source. Electroanalgesia has a lower addictive potential and poses less health threats to the general public, but can cause serious health problems, even death, in people with other electrical devices such as pacemakers or internal hearing aids, or with heart problems.

Pain asymbolia, also called pain dissociation, is a condition in which pain is experienced without unpleasantness. This usually results from injury to the brain, lobotomy, cingulotomy or morphine analgesia. Preexisting lesions of the insula may abolish the aversive quality of painful stimuli while preserving the location and intensity aspects. Typically, patients report that they have pain but are not bothered by it; they recognize the sensation of pain but are mostly or completely immune to suffering from it.

Patient-controlled analgesia (PCA) is any method of allowing a person in pain to administer their own . The infusion is programmable by the prescriber. If it is programmed and functioning as intended, the machine is unlikely to deliver an overdose of medication. Providers must always observe the first administration of any PCA medication which has not already been administered by the provider to respond to allergic reactions.

The most common form of patient-controlled analgesia is self-administration of oral over-the-counter or prescription painkillers. For example, if a headache does not resolve with a small dose of an oral analgesic, more may be taken. As pain is a combination of tissue damage and emotional state, being in control means reducing the emotional component of pain.

Audioanalgesia (also known as audio-analgesia) is the relief of pain using white noise or music without using pharmacological agents while doing painful medical procedures such as dental treatments. It was first introduced by Gardner and Licklider in 1959.

There are many studies of this technique in dental, obstetric, and palliative care contexts. The most recent review reports mixed results for effectiveness. This questionable pain management strategy might prove useful in distraction and sensory confusion, but only when combined with actual pain relief medications. There is no research to suggest these dubious results will ever be effective other than as a means of self-distraction. This measure is similar to breathing exercises during cramps before administration of epidurals.

It has also been suggested that music may stimulate the production of endorphins and catecholamines.

Medication overuse headache is a recognized ICHD (International Classification of Headache Disorders) classification. Over the years different sets of diagnostic criteria have been proposed and revised by the major experts of headache disorders. The term MOH first appeared in the ICHD 2nd edition in 2004. It was defined as a secondary headache, with the aim of emphasising excessive drug intake as the basis of this form of headache. The two subsequent revisions of the diagnostic criteria for MOH (2005 and 2006) refined and extended the definition of the condition on the basis of both its chronicity (headache on more than 15 days/month for more than three months) and drug classes, thereby identifying the main types of MOH. In the case of ergotamine, triptans, opioids and combination medications in particular, intake on > 10 days/month for > 3 months is required, whereas simple analgesics are considered overused when they are taken on > 15 days/month for >3 months.

The most prominent symptoms of erythromelalgia are episodes of erythema, swelling, a painful deep-aching of the soft tissue (usually either radiating or shooting) and tenderness, along with a painful burning sensation primarily in the extremities. These symptoms are often symmetric and affect the lower extremities more frequently than the upper extremities. Symptoms may also affect the ears and face. For secondary erythromelalgia, attacks typically precede and are precipitated by the underlying primary condition. For primary erythromelalgia, attacks can last from an hour to months at a time and occur infrequently to frequently with multiple times daily. Common triggers for these episodes are exertion, heating of the affected extremities, and alcohol or caffeine consumption, and any pressure applied to the limbs. In some patients sugar and even melon consumption have also been known to provoke attacks. Many of those with primary erythromelalgia avoid wearing shoes or socks as the heat this generates is known to produce erythromelalgia attacks. Raynaud's phenomenon often coexists in patients with Erythromelalgia. Symptoms may present gradually and incrementally, sometimes taking years to become intense enough for patients to seek medical care. In other cases symptoms emerge full blown with onset.

The first cases of electroanalgesia were documented by Greek scholars, Plutarch and Socrates, who noticed numbing effects of standing in pools of water on a beach that contained electric fish. The Chinese practice of acupuncture, dating back to 3000 BCE, also utilizes the properties of electroanalgesia by stimulating specific nerves to produce electrical signals which produce pleasurable responses in the brain. Another ancient analgesic method, aging back to 5000 BCE in Sumer, is to use natural minerals, vitamins, and herbs, usually in a mixture with other natural products. Technology invented specifically for electroanalgesia emerged at the beginning of the 1900s.

Medication overuse headache (MOH), also known as rebound headache usually occurs when analgesics are taken frequently to relieve headaches. Rebound headaches frequently occur daily, can be very painful and are a common cause of chronic daily headache. They typically occur in patients with an underlying headache disorder such as migraine or tension-type headache that "transforms" over time from an episodic condition to chronic daily headache due to excessive intake of acute headache relief medications.

MOH is a serious, disabling and well-characterized disorder, which represents a worldwide problem and is now considered the third-most prevalent type of headache. Population-based studies report the prevalence rate of MOH to be 1% to 2% in the general population, but its relative frequency is much higher in secondary and tertiary care.

For people with this disorder, cognition and sensation are otherwise normal; for instance, patients can still feel discriminative touch (though not always temperature), and there are no detectable physical abnormalities.

Because children with the disorder cannot feel pain, they may not respond to problems, thus being at a higher risk of more severe diseases. Children with this condition often suffer oral cavity damage both in and around the oral cavity (such as having bitten off the tip of their tongue) or fractures to bones. Unnoticed infections and corneal damage due to foreign objects in the eye are also seen.

There are generally two types of non-response exhibited:

- Insensitivity to pain means that the painful stimulus is not even perceived: a patient cannot describe the intensity or type of pain.

- Indifference to pain means that the patient can perceive the stimulus, but lacks an appropriate response: they do not flinch or withdraw when exposed to pain.

The primary symptom is hip pain, especially hip pain on the outer (lateral) side of the joint. This pain may appear when the affected person is walking or lying down on that side.

Erythromelalgia is a difficult condition to diagnose as there are no specific tests available. However, reduced capillary density has been observed microscopically during flaring; and reduced capillary perfusion is noted in the patient. Another test that can be done is to have the patient elevate their legs, and note the reversal (from red to pale) in skin color. Tests done at universities include quantitative sensory nerve testing, laser evoked potentials, sweat testing and epidermal sensory nerve fiber density test (which is an objective test for small fiber sensory neuropathy). Due the aforementioned factors, patients may face delays in diagnosis.

Once it has been established that it is not secondary erythromelalgia — see below — a programme of management can be put in place.

Some diseases present with symptoms similar to erythromelalgia. Complex regional pain syndrome (CRPS), for instance, presents with severe burning pain and redness except these symptoms are often unilateral (versus symmetric) and may be proximal instead of purely or primarily distal. Furthermore, attacks triggered by heat and resolved by cooling are less common with CRPS.

Erythromelalgia is sometimes caused by other disorders. A partial list of diseases known to precipitate erythromelalgia is below.

Greater trochanteric pain syndrome (GTPS), also known as trochanteric bursitis, is inflammation of the trochanteric bursa, a part of the hip.

This bursa is at the top, outer side of the femur, between the insertion of the gluteus medius and gluteus minimus muscles into the greater trochanter of the femur and the femoral shaft. It has the function, in common with other bursae, of working as a shock absorber and as a lubricant for the movement of the muscles adjacent to it.

Occasionally, this bursa can become inflamed and clinically painful and tender. This condition can be a manifestation of an injury (often resulting from a twisting motion or from overuse), but sometimes arises for no obviously definable cause. The symptoms are pain in the hip region on walking, and tenderness over the upper part of the femur, which may result in the inability to lie in comfort on the affected side.

More often the lateral hip pain is caused by disease of the gluteal tendons that secondarily inflames the bursa. This is most common in middle-aged women and is associated with a chronic and debilitating pain which does not respond to conservative treatment. Other causes of trochanteric bursitis include uneven leg length, iliotibial band syndrome, and weakness of the hip abductor muscles.

Greater trochanteric pain syndrome can remain incorrectly diagnosed for years, because it shares the same pattern of pain with many other musculoskeletal conditions. Thus people with this condition may be labeled malingerers, or may undergo many ineffective treatments due to misdiagnosis. It may also coexist with low back pain, arthritis, and obesity.

Pain management during childbirth is the treatment or prevention of pain that a woman may experience during labor and delivery. The amount of pain a woman feels during labor depends partly on the size and position of her baby, the size of her pelvis, her emotions, the strength of the contractions, and her outlook. Tension increases pain during labor. Virtually all women worry about how they will cope with the pain of labor and delivery. Childbirth is different for each woman and predicting the amount of pain experienced during birth and delivery can not be certain.

Some women do fine with "natural methods" of pain relief alone. Many women blend "natural methods" with medications and medical interventions that relieve pain. Building a positive outlook on childbirth and managing fear may also help some women cope with the pain. Labor pain is not like pain due to illness or injury. Instead, it is caused by contractions of the uterus that are pushing the baby down and out of the birth canal. In other words, labor pain has a purpose.

These are also called narcotics and are medicines given through an IV or by injection into a muscle. Sometimes, opioids also are given with an epidural or a spinal block. Opioids can make the pain bearable, and doesn't affect the ability to push. Opioids don't get rid of all the pain. They

- are short-acting.

- cause drowsiness.

- cause nausea and vomiting.

- can cause itchiness.

- cannot be given right before delivery because they may slow the baby's breathing and heart rate at birth.

Congenital insensitivity to pain (CIP), also known as congenital analgesia, is one or more rare conditions in which a person cannot feel (and has never felt) physical pain. The conditions described here are separate from the HSAN group of disorders, which have more specific signs and cause. Because feeling physical pain is vital for survival, CIP is an extremely dangerous condition. It is common for people with the condition to die in childhood due to injuries or illnesses going unnoticed. Burn injuries are one of the more common injuries.

The first steps in the evaluation and later management of plexopathy would consist of gathering a medical history and conducting a physical examination by a healthcare clinician. Motor function defect patterns detected within either the upper or lower extremities help with diagnosis of the disorder.

X-rays of the cervical spine, chest, and shoulder are usually ordered if symptoms point to acute Brachial plexopathy. If the physical history reveals a history of diabetes, collagen vascular disease, or symptoms of infection, the physician may order a series of blood tests including a complete blood count (CBC) and a comprehensive metabolic panel (CMP).

Plexopathy is a disorder affecting a of nerves, blood vessels, or lymph vessels. The region of nerves it affects are at the brachial or lumbosacral plexus. Symptoms include pain, loss of motor control, and sensory deficits.

There are two main types of plexopathy: brachial plexopathy and lumbosacral plexopathy. They are usually caused from some sort of localized trauma such as a dislocated shoulder. The disorder can also be caused secondary to a compression, co-morbid vascular disease, infection, or may be idiopathic with an unknown cause. Both plexopathies can also occur as a consequence of radiation therapy, sometimes after 30 or more years have passed, in conditions known as Radiation-induced Brachial Plexopathy (RIBP) and Radiation-induced Lumbosacral Plexopathy (RILP).

Loin Pain Hematuria Syndrome ", aka "LPHS, is the combination of debilitating unilateral or bilateral flank pain and microscopic or macroscopic amounts of blood in the urine that is otherwise unexplained.

Loin pain-hematuria syndrome (LPHS) is a poorly defined disorder characterized by recurrent or persistent loin (flank) pain and hematuria that appears to represent glomerular bleeding. Most patients present with both manifestations, but some present with loin pain or hematuria alone. Pain episodes are rarely associated with low-grade fever and dysuria, but urinary tract infection is not present. The major causes of flank pain and hematuria, such as nephrolithiasis and blood clot, are typically not present. Renal arteriography may suggest focally impaired cortical perfusion, while renal biopsy may show interstitial fibrosis and arterial sclerosis.

The pain is typically severe, and narcotic therapy is often prescribed as a way to manage chronic pain. Sleep can be difficult because the supine position increases pressure on the flank. The onset of pain is often associated with nausea and vomiting, making pain management by oral opiates complicated.

Renal colic is a type of abdominal pain commonly caused by kidney stones.

Renal colic typically begins in the flank and often radiates to the hypochondrium (the part of the anterior abdominal wall below the costal margins) or the groin. It is typically colicky (comes in waves) due to ureteric peristalsis, but may be constant. It is often described as one of the strongest pain sensations known.

Although this condition can be very painful, kidney stones usually cause no permanent physical damage. The experience is said to be traumatizing due to pain, and the experience of passing blood, blood clots, and pieces of the stone. Depending on the sufferer's situation, nothing more than drinking significant amounts of water may be called for; in other instances, surgery may be needed. Preventive treatment can be instituted to minimize the likelihood of recurrence.

There are seven types of attacks. Ninety percent of all patients have their first attack before they are 18 years old. All develop over 2–4 hours and last anywhere from 6 hours to 4 days. Most attacks involve fever.

1. Abdominal attacks, featuring abdominal pain, affect the whole abdomen with all signs of peritonitis (inflammation of abdominal lining), and acute abdominal pain like appendicitis. They occur in 95% of all patients and may lead to unnecessary laparotomy. Incomplete attacks, with local tenderness and normal blood tests, have been reported.

2. Joint attacks mainly occur in large joints, especially in the legs. Usually, only one joint is affected. 75% of all FMF patients experience joint attacks.

3. Chest attacks include pleuritis (inflammation of the pleura) and pericarditis (inflammation of the pericardium). Pleuritis occurs in 40% of patients and makes it difficult to breathe or lie flat, but pericarditis is rare.

4. Scrotal attacks due to inflammation of the tunica vaginalis occurs in up to 5% and may be mistaken for acute scrotum (i.e. testicular torsion).

5. Myalgia (rare in isolation)

6. Erysipeloid (a skin reaction on the legs, rare in isolation)

7. Fever without any of the other symptoms listed above (25%)

Since alveolar osteitis is not primarily an infection, there is not usually any pyrexia (fever) and cervical lymphadenitis (swollen glands in the neck), and only minimal edema (swelling) and erythema (redness) is present in the soft tissues surrounding the socket.

Signs may include:

- An empty socket, which is partially or totally devoid of blood clot. Exposed bone may be visible or the socket may be filled with food debris which reveals the exposed bone once it is removed. The exposed bone is extremely painful and sensitive to touch. Surrounding inflamed soft tissues may overlie the socket and hide the dry socket from casual examination.

- Denuded (bare) bone walls.

Symptoms may include:

- Dull, aching, throbbing pain in the area of the socket, which is moderate to severe and may radiate to other parts of the head such as the ear, eye, temple and neck. The pain normally starts on the second to fourth day after the extraction, and may last 10–40 days. The pain may be so strong that even strong analgesics do not relieve it.

- Intraoral halitosis (oral malodor).

- Bad taste in the mouth.

Severe back pain, saddle anesthesia, incontinence and sexual dysfunction are considered "red flags", i.e. features which require urgent investigation.