Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated inflammatory disorder of the peripheral nervous system. The disorder is sometimes called chronic relapsing polyneuropathy (CRP) or chronic inflammatory demyelinating polyradiculoneuropathy (because it involves the nerve roots). CIDP is closely related to Guillain–Barré syndrome and it is considered the chronic counterpart of that acute disease. Its symptoms are also similar to progressive inflammatory neuropathy. An asymmetrical variant of CIDP is known as Lewis-Sumner Syndrome.

Chronic inflammatory demyelinating polyneuropathy, also known as Vidaurri's disease, is believed to be due to immune cells, which normally protect the body from foreign infection, incorrectly attacking the nerves in the body instead. As a result, the affected nerves fail to respond, or respond only weakly, and on occasion, inordinately, to stimuli, causing numbing, tingling, pain, progressive muscle weakness, loss of deep tendon reflexes (areflexia), fatigue, and abnormal sensations. The likelihood of progression of the disease is high.

CIDP is under-recognized and under-treated due to its heterogeneous presentation (both clinical and electrophysiological) and the limitations of clinical, serologic, and electrophysiologic diagnostic criteria. Despite these limitations, early diagnosis and treatment is important in preventing irreversible axonal loss and improving functional recovery.

Lack of awareness and treatment of CIDP is also due to limitations of clinical trials. Although there are stringent research criteria for selecting patients to clinical trials, there are no generally agreed-on clinical diagnostic criteria for CIDP due to its different presentations in symptoms and objective data. Application of the present research criteria to routine clinical practice often miss the diagnosis in a majority of patients, and patients are often left untreated despite progression of their disease.

Polyradiculoneuropathy describes a condition in which polyneuropathy and polyradiculopathy occur together. An example is Guillain–Barré syndrome.

Treatment with a single course of intravenous immunoglobulin (IVIG) infusions has been demonstrated to be a potentially effective treatment (reported to have caused prolonged remission in a case associated with systemic lupus (Systemic lupus erythematosus) ).

In the common presentation of acute low back pain, pain develops after movements that involve lifting, twisting, or forward-bending. The symptoms may start soon after the movements or upon waking up the following morning. The description of the symptoms may range from tenderness at a particular point to diffuse pain. It may or may not worsen with certain movements, such as raising a leg, or positions, such as sitting or standing. Pain radiating down the legs (known as sciatica) may be present. The first experience of acute low back pain is typically between the ages of 20 and 40. This is often a person's first reason to see a medical professional as an adult. Recurrent episodes occur in more than half of people with the repeated episodes being generally more painful than the first.

Other problems may occur along with low back pain. Chronic low back pain is associated with sleep problems, including a greater amount of time needed to fall asleep, disturbances during sleep, a shorter duration of sleep, and less satisfaction with sleep. In addition, a majority of those with chronic low back pain show symptoms of depression or anxiety.

The American College of Rheumatology has outlined 19 syndromes that are seen in NPSLE. These syndromes encompass disorders of the central and peripheral nervous systems:

- Aseptic meningitis

- Cerebrovascular disease

- Demyelinating syndrome

- Headache

- Movement disorder

- Myelopathy

- Seizure disorders

- Acute confusional state

- Anxiety disorder

- Cognitive dysfunction

- Mood disorder

- Psychosis

- Acute inflammatory demyelinating polyradiculoneuropathy

- Autonomic disorder

- Mononeuropathy (single/multiplex)

- Myasthenia gravis

- Cranial neuropathy

- Plexopathy

- Polyneuropathy

Each of the 19 syndromes are also stand-alone diagnoses, which can occur with or without lupus.

The majority of cases involve the central nervous system (CNS), which consists of the brain and spinal cord. The CNS syndromes can be subcategorized as either focal or diffuse. The focal syndromes are neurological, while the diffuse syndromes are psychiatric in nature. The most common CNS syndromes are headache and mood disorder.

Though neuropsychiatric lupus is sometimes referred to as "CNS lupus", it can also affect the peripheral nervous system (PNS). Between 10-15% of people with NPSLE have PNS involvement. Mononeuropathy and polyneuropathy are the most common PNS syndromes.

Low back pain is not a specific disease but rather a complaint that may be caused by a large number of underlying problems of varying levels of seriousness. The majority of LBP does not have a clear cause but is believed to be the result of non-serious muscle or skeletal issues such as sprains or strains. Obesity, smoking, weight gain during pregnancy, stress, poor physical condition, poor posture and poor sleeping position may also contribute to low back pain. A full list of possible causes includes many less common conditions. Physical causes may include osteoarthritis, degeneration of the discs between the vertebrae or a spinal disc herniation, broken vertebra(e) (such as from osteoporosis) or, rarely, an infection or tumor of the spine.

Women may have acute low back pain from medical conditions affecting the female reproductive system, including endometriosis, ovarian cysts, ovarian cancer, or uterine fibroids. Nearly half of all pregnant women report pain in the lower back or sacral area during pregnancy, due to changes in their posture and center of gravity causing muscle and ligament strain.

Low back pain can be broadly classified into four main categories:

- Musculoskeletal - mechanical (including muscle strain, muscle spasm, or osteoarthritis); herniated nucleus pulposus, herniated disk; spinal stenosis; or compression fracture

- Inflammatory - HLA-B27 associated arthritis including ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and inflammatory bowel disease

- Malignancy - bone metastasis from lung, breast, prostate, thyroid, among others

- Infectious - osteomyelitis; abscess

Neuropsychiatric systemic lupus erythematosus or NPSLE refers to the neurological and psychiatric manifestations of systemic lupus erythematosus. SLE is a disease in which the immune system attacks the body's own cells and tissues. It can affect various organs or systems of the body. It is estimated that over half of people with SLE have neuropsychiatric involvement.

A 2016 review paper found that although the peripheral nervous system is responsible for starting the condition, the central nervous system (CNS) is responsible for continuing the pain even without continuing input from the peripheral nerves.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is characterized by pelvic or perineal pain without evidence of urinary tract infection, lasting longer than 3 months, as the key symptom. Symptoms may wax and wane. Pain can range from mild to debilitating. Pain may radiate to the back and rectum, making sitting uncomfortable. Pain can be present in the perineum, testicles, tip of penis, pubic or bladder area. Dysuria, arthralgia, myalgia, unexplained fatigue, abdominal pain, constant burning pain in the penis, and frequency may all be present. Frequent urination and increased urgency may suggest interstitial cystitis (inflammation centred in bladder rather than prostate). Post-ejaculatory pain, mediated by nerves and muscles, is a hallmark of the condition, and serves to distinguish CP/CPPS patients from men with BPH or normal men. Some patients report low libido, sexual dysfunction and erectile difficulties.

Three types of juvenile arthritis exist—juvenile rheumatoid arthritis (JRA), juvenile chronic arthritis (JCA), and juvenile idiopathic arthritis (JIA), of which JRA is the most common.

JRA again can be divided into three main forms: The classification is based upon symptoms, number of joints involved and the presence of certain antibodies in the blood.

1. Polyarticular arthritis is the first type of arthritis, which affects about 30–40% of children with arthritis and is more common in girls than boys. Typically five or more joints are affected (usually smaller joints such as the hands and feet but many also affect the hips, neck, shoulders and jaw).

2. Oligoarticular (aka pauciarticular) arthritis can be early or late onset and is the second type of arthritis, affecting about 50% of children with juvenile arthritis. This type affects fewer than four joints (usually the large joints such as knees, ankles or wrists) and may cause eye inflammation in girls with positive anti-nuclear antibodies (ANA). Girls younger than eight are more likely to develop this type of arthritis.

3. Systemic disease is the least common form, with 10–20% of children (boys and girls equally) being affected with limited movement, swelling and pain in at least one joint. A common symptom of this type is a high, spiking fever of or higher, lasting for weeks or months, and a rash of pale red spots on the chest, thighs or other parts of the body may be visible.

Not all acute diseases or injuries are severe, and vice versa. For example, a mild stubbed toe is an acute injury. Similarly, many acute upper respiratory infections and acute gastroenteritis cases in adults are mild and usually resolve within a few days or weeks.

The term "acute" is also included in the definition of several diseases, such as severe acute respiratory syndrome, acute leukemia, acute myocardial infarction, and acute hepatitis. This is often to distinguish diseases from their chronic forms, such as chronic leukemia, or to highlight the sudden onset of the disease, such as acute myocardial infarct.

Psychogenic pain, also called psychalgia, is physical pain that is caused, increased, or prolonged by mental, emotional, or behavioral factors.

Headache, back pain, or stomach pain are some of the most common types of psychogenic pain. It may occur, rarely, in persons with a mental disorder, but more commonly it accompanies or is induced by social rejection, broken heart, grief, lovesickness, or other such emotional events.

Sufferers are often stigmatized, because both medical professionals and the general public tend to think that pain from psychological source is not "real". However, specialists consider that it is no less actual or hurtful than pain from other sources.

The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, "or described in terms of such damage"" (emphasis added). In the note accompanying that definition, the following can be found about pain that happens for psychological reasons:

Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons. There is usually no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain.

Medicine refers also to psychogenic pain or psychalgia as a form of chronic pain under the name of "persistent somatoform pain disorder" or "functional pain syndrome". Causes may be linked to stress, unexpressed emotional conflicts, psychosocial problems, or various mental disorders. Some specialists believe that psychogenic chronic pain exists as a protective distraction to keep dangerous repressed emotions such as anger or rage unconscious.

It remains controversial, however, that chronic pain might arise purely from emotional causes. Treatment may include psychotherapy, antidepressants, analgesics, and other remedies that are used for chronic pain in general.

In most cases, juvenile arthritis is caused by the body attacking its own healthy cells and tissues, i.e. autoimmunity, causing the joint to become inflamed and stiff. Once the joint has become inflamed and stiff, damage is done to the joint and the growth of the joint may by changed or impaired.

Some common childhood onset chronic illnesses are cystic fibrosis, cerebral palsy, juvenile diabetes, juvenile rheumatoid arthritis, and cancer. Chronic illness is often a risk factor for developing psychopathologies, due to the psychological toll it takes on the children and their developing brains. Approximately 10 million children in the United States suffer from a childhood onset chronic illness.

VVS is characterized by severe pain with attempted penetration of the vaginal orifice and complaints of tenderness with pressure within the vulval vestibule. Usually there are no reports of pain with pressure to other surrounding areas of the vulva. The feelings of irritation and burning can persist for hours or days following sexual activity, engendering a sense of hopelessness and depression. VVS also can often cause dyspareunia.

The pain may be provoked by contact with an object, such as with the insertion of a tampon or penis or with the pressure from sitting on a bicycle seat, "provoked vestibulodynia", or it may be constant, as in the case of unprovoked, generalized vestibulodynia. Some women have had pain since their first penetration (primary vulvar vestibulitis) while some have had it after a period of time with pain-free penetration (secondary vulvar vestibulitis).

Relationship problems often occur as the result of chronic frustration, disappointment, and depression associated with the condition.

Tension-type headache pain is often described as a constant pressure, as if the head were being squeezed in a vise. The pain is frequently present on both sides of the head at the same time. Tension-type headache pain is typically mild to moderate, but may be severe.

According to the third edition of the International Classification of Headache Disorders, the attacks must meet the following criteria:

- A duration of between 30 minutes and 7 days.

- At least two of the following four characteristics:

- bilateral location

- pressing or tightening (non-pulsating) quality

- mild or moderate intensity

- not aggravated by routine physical activity such as walking or climbing stairs

- Both of the following:

- no nausea or vomiting

- no more than one of photophobia (sensitivity to bright light) or phonophobia (sensitivity to loud sounds)

Tension-type headaches may be accompanied by tenderness of the scalp on manual pressure during an attack.

Based on frequency, tension-type headaches can be sub-classified as

- Infrequent episodic: occurring less than once per month on average, or less than 12 episodes a year;

- Frequent episodic: occurring between 1-14 times per month on average for at least 3 months;

- Chronic: occurring 15 times a month for at least 3 months (CTTH - "chronic tension-type headache").

Chronic conditions have often been used to describe the various health related states of the human body such as syndromes, physical impairments, disabilities as well as diseases. Epidemiologists have found interest in chronic conditions due to the fact they contribute to disease, disability, and diminished physical and/or mental capacity.

For example, high blood pressure or hypertension is considered to be not only a chronic condition itself but also correlated to diseases such as heart attack or stroke. Additionally, some socioeconomic factors may be considered as a chronic condition as they lead to disability in daily life. An important one that public health officials in the social science setting have begun highlighting is chronic poverty and racism.

The list below includes these chronic conditions and diseases:

In 2015 the World Health Organisation produced a report on non-communicable diseases, citing the four major types as:

- Cancers

- Cardiovascular diseases, including cerebrovascular disease, heart failure, and ischemic cardiopathy

- Chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD)

- Diabetes mellitus

Other examples of chronic diseases and health conditions include:

- Addiction

- Alzheimer's disease

- Atrial fibrillation

- Attention deficit hyperactivity disorder

- Autoimmune diseases, such as ulcerative colitis, lupus erythematosus, Crohn's disease, coeliac disease, Hashimoto's thyroiditis, and relapsing polychondritis

- Bipolar disorder

- Blindness

- Cerebral palsy (all types)

- Chronic graft-versus-host disease (GVHD)

- Chronic hepatitis

- Chronic kidney disease

- Chronic osteoarticular diseases, such as osteoarthritis and rheumatoid arthritis

- Chronic pain syndromes, such as post-vasectomy pain syndrome and complex regional pain syndrome

- Depression

- Deafness and hearing impairment

- Eating disorders

- Ehlers–Danlos syndrome (various types)

- Endometriosis

- Epilepsy

- Fibromyalgia

- HIV/AIDS

- Huntington's disease

- Hypertension

- Lyme disease

- Multiple sclerosis

- Myalgic encephalomyelitis ( chronic fatigue syndrome)

- Narcolepsy

- Obesity

- Osteoporosis

- Parkinson's disease

- Periodontal disease

- Postural orthostatic tachycardia syndrome

- Sickle cell anemia and other hemoglobin disorders

- Sleep apnea

- Thyroid disease

- Tobacco Use and Related Conditions

Chronic illness can affect a child’s development at any stage. During infancy and childhood chronic illness can be detrimental to the development of secure attachment, interpersonal trust, self-regulation, and/or peer relation skills. During middle adolescence, chronic illness can prevent a child from being in school on a regular basis. This can affect a child’s academic and social competence. During adolescence, chronic illness can affect the development of autonomy and self-image. It can also interfere with peer & romantic relationships, and the desire for independence can lead to poor treatment compliance.

Vulvar vestibulitis syndrome (VVS), vestibulodynia, or simply vulvar vestibulitis, is vulvodynia localized to the vulvar region. It tends to be associated with a highly localized "burning" or "cutting" type of pain. Until recently, "vulvar vestibulitis" was the term used for localized vulvar pain: the suffix "-itis" would normally imply inflammation, but in fact there is little evidence to support an inflammatory process in the condition. "Vestibulodynia" is the term now recognized by the International Society for the Study of Vulvovaginal Disease.

Vulvar Vestibulitis Syndrome (VVS) is the most common subtype of vulvodynia that affects premenopausal women. The syndrome has been cited as affecting about 10% to 15% of women seeking gynecological care.

Tension headache, also known as tension-type headache, is the most common type of primary headache. The pain can radiate from the lower back of the head, the neck, eyes, or other muscle groups in the body typically affecting both sides of the head. Tension-type headaches account for nearly 90% of all headaches.

Pain medication, such as aspirin and ibuprofen, are effective for the treatment of tension headache. Tricyclic antidepressants appear to be useful for prevention. Evidence is poor for SSRIs, propranolol, and muscle relaxants.

As of 2013 tension headaches affect about 1.6 billion people (20.8% of the population) and are more common in women than men (23% to 18% respectively).

A chronic condition is a human health condition or disease that is persistent or otherwise long-lasting in its effects or a disease that comes with time. The term "chronic" is often applied when the course of the disease lasts for more than three months. Common chronic diseases include arthritis, asthma, cancer, COPD, diabetes and some viral diseases such as hepatitis C and HIV/AIDS.

In medicine, the opposite of chronic is acute. A chronic course is further distinguished from a recurrent course; recurrent diseases relapse repeatedly, with periods of remission in between.

The non-communicable diseases are also usually lasting medical conditions but are separated by their non-infectious causes. In contrast, some chronic diseases, such as HIV/AIDS, are caused by transmissible infections.

In the United States 25% of adults have at least two chronic conditions. Chronic diseases constitute a major cause of mortality, with the World Health Organization (WHO) attributing 38 million deaths a year to non-communicable diseases.

In medicine, describing a disease as acute denotes that it is of short and, as a corollary of that, of recent . The quantitation of how much time constitutes "short" and "recent" varies by disease and by context, but the core denotation of "acute" is always qualitatively in contrast with "chronic", which denotes long-lasting disease (for example, in acute leukemia and chronic leukemia). In addition, "acute" also often connotes two other meanings: onset and , such as in acute myocardial infarction (EMI), where suddenness and severity are both established aspects of the meaning. It thus often connotes that the condition is fulminant (as in the EMI example), but not always (as in acute rhinitis, which is usually synonymous with the common cold). The one thing that acute MI and acute rhinitis have in common is that they are not chronic. They can happen again (as in recurrent pneumonia, that is, multiple acute pneumonia episodes), but they are not the same ongoing for months or years (unlike chronic obstructive pulmonary disease, which is).

A noncount sense of "acute disease" refers to the acute phase, that is, a short course, of any disease entity. For example, in an article on ulcerative enteritis in poultry, the author says, "in acute disease there may be increased mortality without any obvious signs", referring to the acute form or phase of ulcerative enteritis.

Chronic headache, or chronic daily headache (CDH), is classified as experiencing fifteen or more days with a headache per month. It is estimated that chronic headaches affect "4% to 5% of the general population". Chronic headaches consist of different sub-groups, primarily categorized as chronic tension-type headaches and chronic migraine headaches. The treatments for chronic headache are vast and varied. Medicinal and non-medicinal methods exist to help patients cope with chronic headache, because chronic headaches cannot be cured. Whether pharmacological or not, treatment plans are often created on an individual basis. Multiple sources recommend "multimodal treatment", which is a combination of medicinal and non-medicinal remedies. Some treatments are controversial and are still being tested for effectiveness. Suggested treatments for chronic headaches include medication, physical therapy, acupuncture, relaxation training, and biofeedback. In addition, dietary alteration and behavioral therapy or psychological therapy are other possible treatments for chronic headaches.

Sialadenitis (sialoadenitis) is inflammation of a salivary gland. It may be subdivided temporally into acute, chronic and recurrent forms.

Functional constipation, known as chronic idiopathic constipation (CIC), is constipation that does not have a physical (anatomical) or physiological (hormonal or other body chemistry) cause. It may have a neurological, psychological or psychosomatic cause. A person with functional constipation may be healthy, yet has difficulty defecating.