Persistent generalized lymphadenopathy (PGL) is enlarged, painless, non-tender

lymph nodes A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that incl ...

occurring in a couple of different areas for more than three to six months for which no other reason can be found. To expand, the common site where PGL occurs is within the head and neck region; parotid gland alterations and nasopharyngeal lymphatic tissue enlargement are often frequent comorbidities of Persistent generalized lymphadenopathy. Due to lymphoproliferation in the intraglandular lymphoid tissue, obstruction within the epithelium results in cystic expansion, which is the cause of cystic parotid lesions found in PGL.HIV lymphadenopathy: Differential diagnosis and important imaging features : American Journal of roentgenology : Vol. 216, no. 2 (AJR). American Journal of Roentgenology. (n.d.). Retrieved November 18, 2022, from https://www.ajronline.org/doi/full/10.2214/AJR.19.22334?mobileUi=0 This condition frequently occurs in people in the latency period of

HIV/AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...

. The

lymphatic system The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoi ...

is part of the

immune surveillance system In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. Immunity involves both specific and nonspecific components. The nonspecific components act as barriers or eliminators of a wide range of pathoge ...

Blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in th ...

contains

fluid In physics, a fluid is a liquid, gas, or other material that continuously deforms (''flows'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are substances which cannot resist any shea ...

and blood

cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...

s. The fluid, which may contain suspended foreign material such as

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

and

virus A virus is a wikt:submicroscopic, submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and ...

es, seeps through

blood vessel Blood vessels are the structures of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away from ...

walls into the tissues, where it bathes the body cells and exchanges substances with them. Some of this lymph fluid is then taken up by

lymphatic vessel The lymphatic vessels (or lymph vessels or lymphatics) are thin-walled vessels (tubes), structured like blood vessels, that carry lymph. As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system. Lymph vess ...

s and passed back to the heart, where it is again mixed with the blood. On its way, the fluid passes through the

lymph node A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inc ...

s, small nodular organs located throughout the body but concentrated in certain areas such as the

armpit The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded sup ...

s or

groin In human anatomy, the groin (the adjective is ''inguinal'', as in inguinal canal) is the junctional area (also known as the inguinal region) between the abdomen and the thigh on either side of the pubic bone. This is also known as the medial co ...

. These lymph nodes are also known as ''glands'' or ''lymphoid tissue''. If they detect something foreign passing through them, they enlarge. This is called ''

lymphadenopathy Lymphadenopathy or adenopathy is a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes. In cl ...

'' or ''swollen glands''. Usually this is localized (for example, an infected spot on the

scalp The scalp is the anatomical area bordered by the human face at the front, and by the neck at the sides and back. Structure The scalp is usually described as having five layers, which can conveniently be remembered as a mnemonic: * S: The s ...

will cause lymph nodes in the neck on that same side to swell). However, when two or more lymph node groups are involved, it is called ''

generalized lymphadenopathy Generalized lymphadenopathy is swollen lymph glands in many areas of the body. Usually this is in response to a body-wide infectious disease such as influenza and will go away once the person has recovered, but sometimes it can persist long-ter ...

''. Usually this is in response to significant systemic disease and will subside once the person has recovered. Sometimes it can persist long-term, even when no explanation for the lymphadenopathy can be found. PGL is often found in cases of autoimmune disease (where the body is attacking itself). These include diseases such as

rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects synovial joint, joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and ...

lupus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Commo ...

and

sarcoidosis Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly af ...

. Some forms of

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...

will also cause PGL. Sometimes, despite exhaustive investigation, no cause for PGL is found. For the patient and the physician, this can continue to be a source of concern, but many adults have had PGL all their lives and suffered no ill effects. In others, the PGL may persist for a decade or more and then mysteriously subside. Children often have generalized lymphadenopathy of the head and neck, or even PGL, without the finding of a sinister cause. At

puberty Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a b ...

this usually disappears. The

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as Tumor immunology, cancer cells and objects such ...

of some people may be sensitized by exposure to a living

exogenous irritant In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It contrasts with endogeneity or endogeny, the fact of being influenced within a system. Economics In an economic model, an exogeno ...

such as a bacterial or

viral infection A viral disease (or viral infection) occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells. Structural Characteristics Basic structural characteristics, s ...

, which then results in PGL after the organism has been cleared from the body. In some cases the sensitization is caused by non-living exogenous irritants such as

cyclic hydrocarbon A cyclic compound (or ring compound) is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where ...

s (for example, resinous vapours) or pesticides and

herbicides Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page fo ...

References

Lymphatic organ diseases {{blood-disease-stub