What Causes Swollen Lymph Nodes?

Lymph nodes are bean-shaped and small-sized glands located throughout the body. They are involved in the lymph system that is responsible for bringing nutrients, fluid, and waste between the bloodstream and body tissues. Lymph nodes or lymph glands are also important in the ability of the body to fight off illness causes, including bacteria and viruses. Swollen lymph nodes may be noticed in the groin, armpits, under the chin or on the neck.

Causes of Swollen Lymph Nodes

Swollen lymph nodes may be due to infection or illness and they indicate the lymphatic system is fighting to get rid of the responsible agents. There can be a range of causes.

Medication Allergy

Sometimes lymphadenopathy is due to adverse drug reactions and that includes lymph node enlargement as well as anemia, jaundice, enlarged liver and spleen, fever and rash. Some of the drugs which may produce this reaction include isoniazid, allopurinol, phenylbutazone, pyrimethamine, mephenytoin, and phenytoin. Some anti-infective drugs like sulfonamides, penicillins, or cephalosporins may also lead to swollen lymph nodes, rash or fever.

Common Infections

  1. Cold and Flu. Viral infections like the cold can cause swollen lymph nodes, particularly those in the chin and under the neck. They expand as they produce additional lymphocytes (the cells which produce the protein particles that target viruses and other invaders) as well as other cells to fight viruses.
  1. Mononucleosis. Mononucleosis (mono), also known as “the kissing disease”, is spread via close contact and saliva and is most common in those between 15 and 17 years old. It can develop at any age and may be due to CMV (cytomegalovirus) or EBV (the Epstein-Barr virus).The symptoms of mono include swollen lymph nodes, particularly in the armpit and neck, swollen spleen, sore throat, rash, muscle stiffness or aches, general discomfort or uneasiness, fever and drowsiness.
  1. HIV. HIV is an STI, but can also be passed from mother to child during breastfeeding, pregnancy or childbirth. HIV may take years to weaken the immune system enough to develop AIDS, but most people develop an acute HIV infection, an illness with flu-like symptoms that lasts a few weeks.Some symptoms include swollen lymph nodes (especially on the neck), diarrhea, night sweats, joint pain, genital or mouth ulcers, sore throat, chills, rash, muscle aches, headache and fever.

Uncommon Infections

  1. Cat Scratch Disease. This infection is due to the Bartonella bacteria and is transmitted by an infected cat to a human via bites and scratches. The first symptom is usually a blister or bump at the injury site. This is then followed by swollen lymph nodes, overall discomfort, headache, fever (sometimes) and fatigue.
  1. TB. Extrapulmonary TB occurs outside of the lungs and is more common in those with HIV or a weakened immune system or those who previously had TB without symptoms. It can include lymph node TB, which has symptoms, including the lymph nodes swelling persistently, but painlessly (especially in the neck) and eventually releasing fluid via the skin.

Immune System Disorders

  1. Lupus. Lupus is a type of autoimmune disease in which the immune tissue accidentally attacks healthy tissues as opposed to viruses and bacteria. The symptoms will vary based on the severity and organs affected, but some symptoms are universally common. These include fatigue, muscle and joint pain including morning stiffness and swollen joints, skin problems, such as rash, red spots, flakes, and sores, light sensitivity which can worsen the skin rash, (low-grade) fever, weight changes, swollen lymph nodes and headaches.
  1. Rheumatoid Arthritis. RA can affect multiple systems, usually associated with joint inflammation. It is due to overactive lymph nodes with auto-antibodies like anti-CCP and rheumatoid factor. Although the lymph nodes may enlarge throughout the body, they are not painful.


  1. Leukemia. Leukemia is the abnormal increase in white blood cell levels. These immature white blood cells crowd out the other blood cell components, including platelets and red blood cells, and cannot function well. A large portion of leukemia types will be without symptoms early on. Eventually, however, symptoms will develop and they may include swollen lymph nodes particularly in the groin, armpits, or throat, anemia, as well as related issues like generally feeling unwell, pallor, and fatigue, tendency to bleed or bruise easily, susceptibility to various infections, appetite loss, weight loss and a swollen spleen, causing discomfort underneath a person’s lower left rib. Additionally, the extremely high white blood cell count can lead to stroke, prolonged erection, mental status changes, the ears ringing or retinal hemorrhage that causes visual problems.
  1. Hodgkin Lymphoma. This is a cancer affecting lymph tissue that is found in lymph nodes as well as other sites including bone marrow, the liver and the spleen.Symptoms of Hodgkin Lymphoma can include swollen lymph nodes (in the groin, armpits, or neck) which are not painful, unexplained weight loss, soaking night sweats, loss of appetite, unexplained full-body itching, fatigue, chills and fever which come and go.

Want to know how lymph works in detail? Check out this video: