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.

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.

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.

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.

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.

Electroanalgesia poses serious health problems in those patients who need other electrical equipment in their bodies, such as pacemakers and hearing aids, because the electrical signals of the multiple devices can interfere with each other and fail. People with heart problems, such as irregular heartbeat, are also at risk because the devices can throw off the normal electrical signal of the heart.

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.

In general, erythromelalgia seems to consist of neuropathological and microvascular alterations. How this occurs in secondary erythromelalgia is poorly understood and may be specific to the underlying primary condition. Primary conditions that have been shown to elicit erythromelalgia are listed in diagnosis, below.

Primary erythromelalgia is a better understood autosomal dominant disorder. The neuropathological symptoms of primary erythromelalgia arise from hyperexcitability of C-fibers in the dorsal root ganglion. Specifically, nociceptors (neurons responsible for the sensation and conduction of painful stimuli) appear to be the primarily affect neurons in these fibers. This hyperexcitability results in the severe burning pain experienced by patients. While the neuropathological symptoms are a result of hyperexcitability, microvascular alterations in erythromelalgia are due to hypoexcitability. The sympathetic nervous system controls cutaneous vascular tone and altered response of this system to stimuli such as heat likely results in the observed microvascular symptoms. In both cases, these changes in excitability are typically due to mutation of the sodium channel Na1.7. These differences in excitability alterations between the sympathetic nervous system and nociceptors is due to different expression of sodium channels other than Na1.7 in them.

What causes epidemic erythromelalgia in southern China remains unknown although several erythromelalgia-associated poxviruses were isolated from throat swabs of several patients at different counties and two different seasons.

The first symptom of compartment syndrome is pain. Loss of function and decreased pulses or pulselessness, however, are late signs. According to Shears, paresthesia in the distribution of the nerves transversing the affected compartment has also been described as relatively early sign of compartment syndrome, and later is followed by anesthesia (Shears, 2006).

- Pain is often reported early and almost universally. The description is usually of deep, constant, and poorly localized pain out of proportion with the findings on physical examination (often incorrectly described as pain out of proportion to the injury). The pain is aggravated by passively stretching the muscle group within the compartment or actively flexing it (though this finding is not specific to compartment syndrome alone) and is not relieved by analgesia up to and including morphine.

- Paresthesia (altered sensation e.g., "pins & needles") in the cutaneous nerves of the affected compartment is another typical sign.

- Paralysis of the limb is usually a late finding. The compartment may also feel very tense and firm (pressure). Some find that their feet and even legs fall asleep. This is because compartment syndrome prevents adequate blood flow to the rest of the leg.

- A lack of pulse rarely occurs in patients, as pressures that cause compartment syndrome are often well below arterial pressures and pulse is only affected if the relevant artery is contained within the affected compartment.

- Tense and swollen shiny skin, sometimes with obvious bruising of the skin.

- Congestion of the digits with prolonged capillary refill time.

The symptoms of chronic exertional compartment syndrome (CECS) are brought on by exercise and consist of a sensation of extreme tightness in the affected muscles followed by a painful burning sensation if exercise is continued. After exercise is ceased, the pressure in the compartment will decrease within a few minutes, relieving painful symptoms. Symptoms will occur at a certain threshold of exercise which varies from person to person but is rather consistent for a given individual and can range anywhere from 30 seconds of running to about 10–15 minutes of running. CECS most commonly occurs in the lower leg, with the anterior compartment being the most frequently affected compartment. Foot drop is a common symptom of CECS.

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.

Chemotherapy-induced peripheral neuropathy (CIPN) is a progressive, enduring, and often irreversible condition featuring pain, numbness, tingling and sensitivity to cold in the hands and feet (sometimes progressing to the arms and legs) that afflicts between 30% and 40% of patients undergoing chemotherapy. Chemotherapy drugs associated with CIPN include thalidomide, the epothilones such as ixabepilone, the vinca alkaloids vincristine and vinblastine, the taxanes paclitaxel and docetaxel, the proteasome inhibitors such as bortezomib, and the platinum-based drugs cisplatin, oxaliplatin and carboplatin. Whether CIPN arises, and to what degree, is determined by the choice of drug, duration of use, the total amount consumed and whether the patient already has peripheral neuropathy. Though the symptoms are mainly sensory – pain, tingling, numbness and temperature sensitivity – in some cases motor nerves are affected, and occasionally, also, the autonomic nervous system.

CIPN often follows the first chemotherapy dose and increases in severity as treatment continues, but this progression usually levels off at completion of treatment. The platinum-based drugs are the exception; with these drugs, sensation may continue to deteriorate for several months after the end of treatment. Some CIPN appears to be irreversible. Pain can often be helped with drug or other treatment but the numbness is usually resistant to treatment.

CIPN disrupts leisure, work, and family relations, and the pain of CIPN is often accompanied by sleep and mood disturbance, fatigue and functional difficulties. A 2007 American Cancer Society study found that most patients did not recall being told to expect CIPN, and doctors monitoring the condition rarely asked how it affects daily living but focused on practical effects such as dexterity and gait. It is not known what causes the condition, but microtubule and mitochondrial damage, and leaky blood vessels near nerve cells are some of the possibilities being explored.

Pain disorder is chronic pain experienced by a patient in one or more areas, and is thought to be caused by psychological stress. The pain is often so severe that it disables the patient from proper functioning. Duration may be as short as a few days or as long as many years. The disorder may begin at any age, and occurs more frequently in girls than boys. This disorder often occurs after an accident or during an illness that has caused pain, which then takes on a 'life' of its own.

The most common symptoms of IC/BPS are suprapubic pain, urinary frequency, painful sexual intercourse, and waking up from sleep to urinate.

In general, symptoms may include painful urination described as a burning sensation in the urethra during urination, pelvic pain that is worsened with the consumption of certain foods or drinks, urinary urgency, and pressure in the bladder or pelvis. Other frequently described symptoms are urinary hesitancy (needing to wait for the urinary stream to begin, often caused by pelvic floor dysfunction and tension), and discomfort and difficulty driving, working, exercising, or traveling. Pelvic pain experienced by those with IC typically worsens with filling of the urinary bladder and may improve with urination.

During cystoscopy, 5–10% of people with IC are found to have Hunner's ulcers. A person with IC may have discomfort only in the urethra, while another might struggle with pain in the entire pelvis. Interstitial cystitis symptoms usually fall into one of two patterns: significant suprapubic pain with little frequency or a lesser amount of suprapubic pain but with increased urinary frequency.

There are two states of consciousness that may be present:

- Awareness: That is, patients seem to be cognizant responding to commands but with no postoperative recall or memory of the events.

- Awareness and recall: That is, patients can recall events postoperatively, but were not necessarily conscious enough to respond to commands.

The incidence of a state with both responses in diverse degrees is also possible. The drugs that induce paralysis would also prevent responding to commands.

Anesthesia awareness, also referred to as accidental awareness during general anaesthesia (AAGA) or unintended intra-operative awareness, is a potential complication occurring during general anesthesia where the intended state of complete unconsciousness is not maintained throughout the whole procedure. It can occur either because of failure to deliver sufficient anesthetic medication to the patient's body, or because of individual patient factors that mean the patient is resistant to what would normally be an adequate dose of anesthetic medication.

Giggle incontinence, giggle enuresis or enuresis risoria is the involuntary release of urine in response to giggling or laughter. The bladder may empty completely or only partially.

Giggle incontinence is more common in children than adults, typically appearing at ages 5 to 7, and is most common in girls near the onset of puberty. The condition tends to improve with age, with fewer episodes during the teenage years, but may persist into adulthood. A survey of 99 student nurses indicated that about 25% had experienced such a wetting event during their lifetime, and about 10% were still susceptible in their late teens.

Giggle incontinence is a special form of urge incontinence, and is not the same as stress incontinence, which is generally brought on by participating in vigorous sport.

The DSM-IV-TR specifies three coded subdiagnoses: pain disorder associated with psychological factors, pain disorder associated with both psychological factors and a general medical condition and pain disorder associated with a general medical condition (although the latter subtype is not considered a mental disorder and is coded separately within the DSM-IV-TR). Conditions such as dyspareunia, somatization disorder, conversion disorder, or mood disorders can eliminate pain disorder as a diagnosis. Diagnosis depends on the ability of physicians to explain the symptoms and on psychological influences.

Interstitial cystitis (IC), also known as bladder pain syndrome (BPS), is a type of chronic pain that affects the bladder. Symptoms include feeling the need to urinate right away, needing to urinate often, and pain with sex. IC/BPS is associated with depression and lower quality of life. Many of those affected also have irritable bowel syndrome and fibromyalgia.

The cause of IC/BPS is unknown. While it can, it does not typically run in a family. The diagnosis is usually based on the symptoms after ruling out other conditions. Typically the urine culture is negative. Ulceration or inflammation may be seen on cystoscopy. Other conditions which can produce similar symptoms include urinary tract infection (UTI), overactive bladder, sexually transmitted infections, endometriosis, bladder cancer, and prostatitis.

There is no cure for interstitial cystitis. Treatments that may improve symptoms include lifestyle changes, medications, or procedures. Lifestyle changes may include stopping smoking and reducing stress. Medications may include ibuprofen, pentosan polysulfate, or amitriptyline. Procedures may include bladder distention, nerve stimulation, or surgery. Pelvic floor exercises and long term antibiotics are not recommended.

In the United States and Europe it is estimated that around 0.5% of people are affected. Women are affected about five times as often as men. Onset is typically in middle age. The term "interstitial cystitis" first came into use in 1887.

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.

In voluntary urination, the bladder's normally relaxed detrusor muscle contracts to squeeze urine from the bladder.

One study, of 109 children diagnosed with giggle incontinence at Schneider Children's Hospital in New York, concluded that the cause of giggle incontinence is involuntary contraction of the detrusor muscle induced by laughter.

Because the complaint is difficult to reproduce under controlled conditions, its triggering mechanism is not clearly understood, but may be related to cataplexy, a sudden transient episode of loss of muscle tone often triggered by strong emotions.