symptom complex

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(sin'drōm), This word is not properly applied to a solitary symptom or sign.
The aggregate of symptoms and signs associated with any morbid process, together constituting the picture of the disease.
See also: disease.
[G. syndromē, a running together, tumultuous concourse; (in med.) a concurrence of symptoms, fr. syn, together, + dromos, a running]
Farlex Partner Medical Dictionary © Farlex 2012


The combination of signs and symptoms associated with a particular morbid process, which together constitute the picture of a disease or inherited anomaly.
See also: disease
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


(kom'pleks?) [L. complexus, woven together]
1. Intricate.
2. Of a complicated nature.
3. A group of interrelated biological entities.
4. An atrial or ventricular systole as it appears on an electrocardiographic tracing.
5. All the ideas, feelings, and sensations connected with a subject.
6. A subconscious idea (or group of ideas) that has become associated with a repressed wish or emotional experience and that may influence behavior, although the person may not realize the connection with the repressed thoughts or actions.
7. In Freudian theory, a grouping of ideas with an emotional background. These may be harmless, and the individual may be fully aware of them, e.g., an artist sees every object with a view to a possible picture and is said to have established a complex for art. Often, however, the complex is aroused by some painful emotional reaction such as fright or excessive grief that, instead of being allowed a natural outlet, becomes unconsciously repressed and later manifests itself in some abnormality of mind or behavior. According to Freud, the best method of determining the complex is through psychoanalysis. See: Electra complex; Jocasta complex; Oedipus complex
8. An anatomical or intracellular structure.

AIDS-dementia complex

Abbreviation: ADC
Encephalopathy caused by direct infection of brain tissue by HIV. This condition affects patients with severe immunosuppression more often than those whose immune function is stronger. Central nervous system HIV infection affects as many as 15% of AIDS patients, but in 1997 its incidence decreased to approx. 30% of its previous occurrence because of the effectiveness of highly active antiretroviral therapy (HAART). Central nervous system HIV infections in children tend to be more pronounced than those in adults.


The exact cause of AIDS dementia is unknown, but current theories suggest that it results from HIV infection of macrophages in the brain (microglia) and the destructive release of cytokines that disrupt neurotransmitter function.


AIDS dementia is characterized by slow, progressive memory loss, decreased ability to concentrate, a general slowing of cognitive processes, and mood disorders. Motor dysfunction may also be present, including ataxia, bowel and bladder incontinence, and seizures. Higher levels of HIV RNA in the cerebrospinal fluid (CSF viral load) are correlated with increased problems.


Treatment options may include highly active antiretroviral therapies. Since their introduction the incidence of AIDS-dementia complex has decreased.

Patient care

The patient's mental status and level of consciousness must be assessed and documented. Clear documentation is essential to track a patient's changes over time. Orientation to person, place, and time; thought processes (cognition); verbal communication skills; and memory losses can be determined through simple conversations that reveal the patient's ability to recall normal details of the day and previous teaching. Particular attention is paid to patients' abilities to comply with their complex medication regimen; inability to do so requires another person to assume responsibility for this task. The patient's affect and mood; the presence of agitated, restless, or lethargic behavior; and the extent to which clothing is clean and appropriate for the weather may reveal progressing dementia when compared with previously documented mental status assessments.

Interventions are based on clear communication. As patients develop dementia, they may become frightened, and a consistently gentle approach with positive feedback is essential. Clocks, calendars, and memory aids help the patient become reoriented. Step-by-step written instructions should be given to augment verbal instructions. Caregivers need to learn how to reorient the patient, how to recognize and treat hallucinations, how to create a safe environment, how to ensure that basic hygiene needs are met, and how to document medication schedules and intake because patients may forget to eat or drink adequately.

Synonym: HIV-associated dementia See: AIDS

AIDS-related complex

Abbreviation: ARC
The symptomatic stage of infection with human immunodeficiency virus (HIV) before the onset of AIDS. Its clinical signs include fatigue, intermittent fevers, weight loss greater than 10%, chronic or persistent intermittent diarrhea, night sweats, diminished delayed hypersensitivity (skin test) response to common allergens, presence of HIV antibodies in blood, and decreased CD4+ T-lymphocyte count.

amygdaloid complex


anti-inhibitor coagulant complex

A blood product derived from human plasma, used to augment the effects of clotting factors given to patients with hemophilia. Hemophiliacs who have received repeated injections of clotting factors may develop antibodies to those factors, which decreases the effectiveness of hemophilia treatments. Anti-inhibitors are used to counteract the effect of the unwanted antibodies

castration complex

A morbid fear of being castrated.

Eisenmenger complex

See: Eisenmenger syndrome

Ghon complex

See: Ghon complex

HLA complex

Major histocompatibility complex.

immune complex

A substance formed when antibodies attach to antigens to destroy them. These complexes circulate in the blood and may eventually attach to the walls of blood vessels, producing a local inflammatory response. Immune complexes form in type III hypersensitivity reactions and are involved in the development of glomerulonephritis, serum sickness, arthritis, and vasculitis.

inferiority complex

The condition of having low self-esteem. It is a 20th-century term stemming from Adlerian therapy.

inferior olivary complex

Inferior olive.

major histocompatibility complex

Abbreviation: MHC
A group of genes on chromosome 6 that code for the antigens that determine tissue and blood compatibility. In humans, histocompatibility antigens are called human leukocyte antigens (HLA) because they were originally discovered in large numbers on lymphocytes. There are thousands of combinations of HLA antigens. Class I MHC antigens (HLA-A, HLA-B, and HLA-C) are found on all nucleated cells and platelets. Class II antigens (HLA-DR, HLA-DQ, and HLA-DP) are found on lymphocytes and antigen processing cells and are important in the specific immune response. In tissue and organ transplantation, the extent to which the HLA or “tissue type” of the donor and recipient match is a major determinant of the success of the transplant.
Synonym: HLA complex See: histocompatibility locus antigen

membrane attack complex

The combination of complement factors C5 through C9 that directly attack and kill the cell membranes of microorganisms during the terminal attack phase of the complement cascade.
See: complement; inflammation

Mycobacterium avium complex

Abbreviation: MAC, MAI
An atypical mycobacterium that causes systemic bacterial infection in patients with advanced immunosuppression, esp. those with AIDS. It occasionally causes lung infections in patients with chronic obstructive lung disease. Synonym: Mycobacterium avium-intracellulare complex


MAC infection in AIDS patients can cause fatigue, fever, weight loss, cachexia, pancytopenia, and death.


Multiple antimicrobial agents, given at the same time and for long courses, are required to treat MAC. Combination therapy may include a macrolide with drugs such as rifabutin, ethambutol, ciprofloxacin, amikacin, and/or clofazimine.

Mycobacterium avium-intracellulare complex

Mycobacterium avium complex.

nodal premature complex

Abbreviation: NPC
Ectopic cardiac beat originating in the atrioventricular node.

nuclear pore complex

A collection of membrane-associated proteins that regulate the passage of large molecules between the cytoplasm and the cell nucleus.

oculomotor complex

A group of interrelated nuclei found near the midline in the rostral midbrain. They include the oculomotor nucleus and the Edinger-Westphal nucleus, and they innervate somatic muscles, e.g., inferior rectus and levator palpebrae muscles, and visceral muscles (preganglionic parasympathetic axons to the ciliary ganglia) via the oculomotor nerve (CN III).

olivary complex

Olive (2).

osteomeatal complex

The middle turbinate and the middle meatus of the nose.

QRS complex

The pattern traced on the surface electrocardiogram by depolarization of the ventricles. In the anterior chest leads, e.g., V1 to V3, the complex normally consists of a small initial downward deflection (Q wave), a large upward deflection (R wave), and a second downward deflection (S wave). The normal duration of the complex is 0.06 to 0.11 sec. Longer QRS complexes are seen in premature ventricular beats and ventricular arrhythmias.

QRST complex

Q-T interval.

superiority complex

Exaggerated conviction that one is better than others, a pretense used to compensate for a real or imagined inferiority.

superior olivary complex

Superior olive.

symptom complex


tuberous sclerosis complex

Tuberous sclerosis.
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
The presence and relative frequency of two major dyspeptic symptom complexes in this study is revealing.
Physicians should promptly evaluate returning travelers for schistosomiasis even if they do not report the complete symptom complex. However, in the absence of effective treatment for acute schistosomiasis, new diagnostic methods and new drugs that affect the parasite at an early stage are needed.
For any one pest, however, the symptom complex is usually specific.
When the answer is not obvious, yet patients display the symptom complex suggestive of the disorder, then it is time to consider a referral to a urologist to get a more definitive diagnosis and clarity around the process.
Some professionals categorically refute the existence of m MTBI-related symptom complex. How can there be an injury to the brain, they ask, when there has been no extensive loss of consciousness, and subsequent medical tests do not show evidence of structural damage?
As the viral inflammation descends the respiratory tree, the symptom complex changes.
[1] The symptom complex includes upper abdominal pain or discomfort, postprandial fullness, bloating, belching, early satiety, anorexia, nausea, heartburn and occasional vomiting.
The mountaineer may, as a consequence, develop a symptom complex characterized by headache, nausea, anorexia and vomiting2.
Syncope is a symptom complex that is composed of a brief loss of consciousness associated with an inability to maintain postural tone that spontaneously and completely resolves without medical intervention.
Urgency is a sensation associated with abnormal bladder behaviour during the filling phase, which is difficult to define and explain to others who have not experienced it, but is quite distinct from normal urge (see Figure 1).[sup.1] Urgency is a pathological symptom, which leads to the rest of the urinary symptom complex - reduced intervoid interval, nocturia, incontinence and reduced urinary volume.
Delayed uterine re-inversion: a unique symptom complex. Am J Obstet Gynecol.
(14,15,18) Despite the striking radiographic appearance of an ossified and elongated stylohyoid process, the significance of this abnormality has not been appreciated except by otolaryngolists who are familiar with the symptom complex. (14)

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