Lymph nodes are located throughout the body. They are part of the lymphatic system, consisting of the lymphatic vessels and the lymphatic organs. They are responsible for the immune system.
The lymphatic organs can be divided into primary and secondary organs. In the primary lymphatic organs - the bone marrow and the thymus (in German Bries) - the lymphocytes are formed. They belong to the white blood cells and arise from stem cells from the bone marrow.
Their maturation into finished immune cells, which can recognize foreign substances and dangerous antigens, takes place in the secondary lymphoid organs. In addition to the lymph nodes, these include the spleen, lymphoid tissue in the mucous membranes (for example, the tonsils ( tonsils )) and the appendix in the intestine (often incorrectly referred to as an appendix).
Read detailed information on the topic: Lymphatic Organs
Here are antigens, so potentially dangerous foreign substances that circulate in the body, checked. The spleen is responsible for antigens that circulate in the blood. The lymphatic tissue in the mucous membranes examines the antigens that have penetrated the surface of the mouth superficially into the mucous membranes. Lymph nodes, on the other hand, react to substances that have already penetrated the tissue and spread through the lymphatic vessels.
Because the lymphatic vessels form a drainage system that absorbs tissue fluid and feeds it back into the bloodstream. It consists of tiny, blindly ending vessels that exist in almost all organs (the central nervous system, for example, is an exception). They take up free fluid, direct it centrally over ever-widening lymphatic vessels, and finally lead it into the venous angle (where the veins unite from the neck and the arm), with the largest part reaching the left vein angle, from where they pass with the venous blood flowing over the superior vena cava.
The lymph nodes are interposed between the lymphatic vessels and serve as filter stations.
The lymph nodes are usually roundish or bean-shaped, are between 2 and 20 mm in size and filter the lymph before it is returned to the bloodstream.
Lymph refers to the fluid in the lymphatic vessels, ie the intermediate step between tissue fluid and blood plasma. It is slightly yellowish, consists mainly of water, contains lymphocytes and also some electrolytes and proteins. After meals, it can also be cloudy and milky white, since the lymph also absorbs fats.
There are approximately 600 to 700 lymph nodes throughout the body, with each organ and body part having their own so-called regional lymph node, which is the first filtration station for this area. The area for which this lymph node is responsible, so to speak, is called a tributary area.
The afferent lymphatic vessels enter the lymph nodes from all directions, then the lymph flows through certain pathways, the so-called sinuses, through the lymph node to a pole (the hilum), where it is discharged again via an exiting lymphatic vessel. In the tissue of the lymph nodes are lymphocytes, which have reached there via an afferent artery and which can come here directly with antigens from the lymph in contact.
The most important lymph node stations are located on the head (below and behind the ear, on the occiput, on the lower jaw and on the chin), on the neck (neck and along the neck vessels), in the armpit, in the abdomen and chest, on the collarbone and in the groin,
The lymph nodes in the neck area make up about one third of all lymph nodes. The body is here due to the air and food paths pathogens particularly exposed, also flows here a large part of the lymph together, namely the head, neck, trunk and arms.
Above all, the lymph nodes are located along the front of the trachea and around the thyroid gland and laterally along the blood vessels and on the sternocleidomastoid muscle (in German, the "big head turn": the muscle that emerges when turning the head to one side). There are superficial and deep lymph nodes, with most of the neck lymphatic drainage occurring through the lower nodes along the internal jugular veins.
Since many lymph nodes on the neck are relatively superficial, they are often easy to see and feel, especially if they are swollen.
In diseases in the so-called tributary area (see above) of a lymph node, this increases. The lymph enters foreign cells and particles into the regional lymph nodes, whereupon the ducts expand and more lymphocytes accumulate. Causes for the swelling of a lymph node can be an inflammation in the area of the lymph node, a tumor disease of another organ, or a lymphoma itself.
In most cases, swelling in the neck is due to swollen cervical lymph nodes.
These can also be painful under pressure and are a reaction to harmless inflammations in the neck and head area or the respiratory tract, for example, a cold, an almond or tooth inflammation.
But more serious bacterial or viral infections such as Lyme disease after a tick bite, tuberculosis, glandular fever or HIV can cause lymph node swelling. It indicates that the immune system is active. Normally, the lymph nodes swell after expired disease again. However, they can still be felt as small, painless, shifting indurations.
This phenomenon of swollen lymph nodes is called reactive lymph node swelling or lymphadenitis. The benign enlargements can also be called pseudolymphoma.
Painless, swollen lymph nodes, which have already hardened over a longer period of time and can not be delimited well to the surrounding tissue, ie are not displaceable, may possibly arise as a result of scattering tumor cells. If an organ is affected by a tumor, then the tumor cells can reach the regional lymph nodes via the lymph fluid, where they are filtered, accumulate and grow. Thus, a lymph node metastasis is formed and the lymph node becomes larger. Lymph node metastasis belongs to the regional metastases. By contrast, distant metastases (often in the bones, liver or brain) are scattered via the bloodstream.
Lymph node metastases usually appear only when the primary tumor is already advanced. They may be accompanied by symptoms such as heavy weight loss, night sweats and fever, or they may be the first symptom to detect a tumor.
Tumors in the head and neck area that could spread to the cervical lymph nodes are, for example, the oral cavity, thyroid, or nasopharyngeal carcinoma.
The third cause of enlarged lymph nodes is malignant lymphoma. It describes neoplasms of lymphoid cells through uncontrolled growth. A distinction is made between Hodgkin's lymphomas and non-Hodgkin's lymphomas. Hodgkin's lymphoma is made up of B lymphocytes, a subspecies of lymphocytes responsible for the production of antibodies. After the initial development in a lymph node, it spreads continuously through the lymphatic system. The causes of Hodgkin's lymphoma are largely unknown. Decisive for the prognosis is the spread stage at the time of diagnosis.
Typical accompanying symptoms include fever, night sweats and weight loss. With large lymphomas it can come to shortness of breath and an upper influence congestion. The enlarged lymph node presses off a vein, which then emerges from the congestion.
Non-Hodgkin's lymphomas can still be divided into B-cell and T-cell lymphomas.
Only unilaterally swollen lymph nodes can occur as a result of a localized unilateral infection.
Even malignant changes, ie tumors in the tributary area of the lymph node or lymphoma of the lymph node itself can first manifest themselves on one side only.
In order to diagnose the cause of a swollen lymph node, it is checked for its size, its consistency ( soft or hard ), its surface ( smooth or rough ), the delimitation of the surrounding tissue, the mobility, and pressure pain.
A normal finding would look as follows: not palpable or less than 1 cm in size, soft, smooth surface, definable, displaceable and not tender painful.
If there is a suspicion of a malignant disease, a sampling (biopsy) is performed. The excised tissue is examined microscopically and checked for malignant changes.
Lymph nodes that are enlarged because of an infection usually swell again after the disease has ended. In severe bacterial infections may optionally be treated with antibiotics, viral infections are usually only symptomatic, ie, fever-reducing, treated.
In the case of lymph node metastases, all lymph nodes of the corresponding lymph drainage area are generally removed as part of the surgical removal of the primary tumor in order to prevent further metastasis via the lymphatic system. This procedure is called lymphadenectomy. Lymphedema can form as a result of this removal, ie accumulation of water in the surrounding tissue, as the absorption and discharge through the lymphatic vessels is interrupted.
In breast or prostate cancer, the concept of the sentinel lymph node is implemented. In this case, the lymph node closest to the primary tumor is examined for metastatic tumor cells. If it is tumor-free, it is assumed that the following lymph nodes are not yet affected and do not need to be removed.
In the case of chemo- or radiotherapy, this also affects the lymph node metastases and may contribute to the reduction of the lymph nodes.
Malignant lymphoma is also treated with a combination of radiation and chemotherapy or just chemotherapy. The intensity and type of treatment depends on the stage of the disease.
Against the swollen lymph nodes on the neck during a flu infection, you can do something yourself within a certain framework. Since the lymph nodes in an infection after healing heal again, one can try to speed up this process by supporting the immune system. Rest, rest and a healthy, vitamin-rich diet should accelerate the healing process.
Hodgkin's disease ( Hodgkin's lymphoma ) takes a deadly course without treatment, but with modern therapeutic strategies good cure rates can be achieved. Depending on the stage of the disease, they are between 70% and over 90%. About 10% to 20% of patients experience a second tumor ( recurrence ) in the years following treatment.
The course and prognosis of non-Hodgkin's lymphoma (NHL) vary widely. Low levels of malignant NHL often take many years, causing patients to die from uncontrollable infections and bleeding. Highly malignant NHL can be cured by intensive therapy.
In most cases, swollen lymph nodes on the neck are harmless and seen as a sign of activation of the immune system against an acute infection.
If the swelling persists for a long time and structural changes attract attention, you should consult a doctor as a precaution and clarify the cause.