The term “swollen glands” refers to the enlargement of lymph nodes, which are small, bean-shaped organs belonging to the lymphatic system. These nodes are distributed throughout the body and serve as organized centers for immune defense. When a person notices a palpable lump in the neck, armpit, or groin, they are feeling an enlarged lymph node, a condition medically known as lymphadenopathy. This swelling is typically a sign that the body’s immune system is actively working to filter out foreign invaders or abnormal cells. Swollen nodes are not the issue itself but rather a physical manifestation of an underlying process, usually reflecting the body’s response to an infection or inflammation.
The Lymphatic System and Glands
The lymphatic system is a network of vessels, fluid, and organs that plays a major role in both fluid balance and immune function. Lymph fluid, which is a clear or yellowish fluid containing white blood cells, proteins, and fats, is collected from body tissues and circulated through these vessels. This fluid passes through hundreds of lymph nodes, which act as biological filters strategically positioned throughout the body. Inside these nodes are specialized immune cells, primarily lymphocytes and macrophages, which are tasked with trapping and destroying foreign material like bacteria, viruses, and damaged cells. Swelling occurs when a lymph node encounters a threat, causing the immune cells within it to rapidly multiply and accumulate to fight the infection. This proliferation of cells causes the node to expand in size, making it noticeable to the touch.
Common and Serious Causes of Swelling
The vast majority of lymph node swelling is a temporary, localized response to a common infection. Viral infections, such as the common cold, flu, or infectious mononucleosis (Epstein-Barr virus), are the most frequent culprits for lymphadenopathy. Swelling related to these acute infectious causes is generally characterized as soft, mobile, and tender to the touch, indicating an active, localized inflammatory process.
Bacterial infections, including strep throat or an infected cut, also commonly cause nearby nodes to swell as they drain the area. In these cases, the swelling is typically localized and subsides once the underlying infection is treated or resolves on its own. A node that remains enlarged for an extended period, such as longer than four weeks, warrants further investigation even if the initial cause was benign.
Swollen nodes can also be a sign of a systemic inflammatory or autoimmune condition, such as lupus or rheumatoid arthritis, where the immune system mistakenly attacks the body’s own tissues. In these instances, the swelling may be more generalized, affecting multiple, non-adjacent groups of nodes. The distinction between a temporary infectious cause and a chronic systemic issue is often determined by the node’s persistence and the presence of other symptoms.
A small number of cases involve a more serious cause, specifically malignancy like lymphoma, leukemia, or the spread of cancer from another site. Nodes that are potentially malignant often have distinct physical characteristics, including feeling hard, fixed, and non-tender. Swelling in the supraclavicular area, which is located just above the collarbone, carries a higher risk of being associated with an underlying cancer.
Where Swelling Occurs
The location of the swollen lymph node provides a direct clue to the source of the problem because lymph fluid drains from specific regions of the body into specific node clusters. Swelling in the cervical nodes, located in the neck, is the most frequently observed lymphadenopathy. This location is typically associated with infections of the head and throat, such as tonsillitis, ear infections, dental abscesses, or upper respiratory illnesses.
Nodes under the arm, known as axillary nodes, drain the arms, chest wall, and breast tissue. Swelling here can indicate an infection in the hand or arm, but it is also a location monitored closely for the spread of breast cancer. Swollen nodes in the groin, or inguinal nodes, are most commonly related to infections or injuries affecting the legs, feet, or the genital area.
When a person experiences generalized lymphadenopathy, meaning nodes are swollen in two or more non-neighboring areas, it suggests a systemic process affecting the entire body. This pattern is seen with viral illnesses like mononucleosis or HIV, but also with certain autoimmune diseases or widespread malignancies. The distribution of the swelling helps healthcare providers narrow the diagnostic focus.
Medical Evaluation and Testing
A medical evaluation begins with a detailed history of the patient’s symptoms, focusing on the duration of the swelling, recent illnesses, travel, and exposures. The physical examination is a foundational step where the physician assesses the node’s characteristics, including its size, consistency (soft, firm, or hard), mobility (mobile or fixed), and whether it is tender. Nodes exceeding one centimeter in diameter are considered enlarged in adults.
Initial diagnostic testing often involves a complete blood count (CBC) with differential, which measures various components of the blood to look for signs of infection or other disorders like leukemia. Depending on the clinical suspicion, targeted blood tests may also be ordered to check for specific viruses, such as Epstein-Barr virus or HIV. If the cause remains unclear or if the node feels suspicious, imaging studies may be used to assess its structure.
An ultrasound is often the first-line imaging choice, as it can characterize the node’s internal architecture and vascularity. A computed tomography (CT) scan may be necessary to visualize nodes deep within the chest or abdomen. If malignancy is suspected or if the swelling persists without an identifiable cause, the final step involves tissue sampling. A fine-needle aspiration (FNA) can collect a small sample of cells for analysis, while an excisional biopsy, which removes the entire node, is considered the gold standard for definitively diagnosing conditions like lymphoma.