Causes of Swollen Groin Lymph Nodes

The lymph nodes of the groin, or inguinal lymph nodes, are located in the crease between the leg and pelvis. There are two types of inguinal lymph nodes – superficial and deep. They often swell due to an infection or cancer in the areas from which they drain lymph (lymphatic fluid). For this reason, swelling of the groin lymph nodes is an important clinical indication of pathology within the lower abdominal wall, legs, groin, buttocks, anus, perineum and external genitalia.

Anatomy of Inguinal (Groin) Lymph Nodes

Lymph nodes are located throughout the body with each group being responsible for draining a particular area. The common lymph nodes that swell are found in the neck (cervical), armpit (axillary), and groin (inguinal), as well as in numerous other areas of the body.

There are about 10 lymph nodes that collectively form the group known as the superficial lymph nodes. They drain the skin and subcutaneous tissue (which lies just beneath the skin) of the lower abdominal wall below the level of the umbilicus, gluteal region (buttocks), perineum, lower part of anus, external genital organs and the leg.

The superficial lymph nodes themselves drain into the deep inguinal lymph nodes. There are about 3 to 5 of these deep inguinal lymph nodes which filter the lymph and return it to the circulation.

Causes of Enlargement of Inguinal Lymph Nodes

Infections

Infections of the leg or genitals may cause swelling of the lymph nodes in the groin. Systemic infections may also cause lymph node swelling of the three main groups – groin, neck or armpits.

  • Sexually transmitted diseases (STDs) such as syphilis, gonococcal infection, chancroid, herpes simplex, lymphogranuloma venereum (LGV) may cause swelling of the inguinal lymph nodes.
  • Bubonic plague caused by Yersinia pestis, may cause extremely tender lymph node enlargement in the groin, accompanied by redness and inflammation of the overlying skin. Lymph nodes of the armpit and neck may also be involved.
  • Viral infections such as infectious mononucleosis may affect the whole body and cause generalized lymph node swelling in various parts of the body, such as neck, armpit or groin.
  • Bacterial infections of the skin and subcutaneous tissue, muscles and bone of the leg or pelvis may also cause swelling of the groin lymph nodes.
  • Toxoplasmosis caused by the parasite Toxoplasma gondii may also result in swollen lymph nodes. Most people do not exhibit any signs or symptoms of the disease and no treatment may be necessary but in babies born to infected mothers or in immunocompromised patients such as those with HIV/AIDS, it can turn into a serious infection. Flu-like symptoms such as body ache, headache, fever, fatigue and sore throat may be accompanied by enlarged lymph nodes.

Cancer and Tumors

Many forms of cancer occurring within the area drained by the groin lymph nodes will lead to swelling (lymphadenopathy). Lymph node swelling usually occurs due to malignant tumors.

  • Leukemia is the cancer of the body’s blood forming tissues, including bone marrow and lymphatic system.
  • Lymphoma is the cancer of the lymph node. It usually starts in the lymph node and may spread to other parts of the body. It may involve groups of lymph nodes in various parts of the body.  There are two types of lymphomas – Hodgkin’s disease and Non-Hodgkin’s disease.
  • Pelvic malignancy (cancer) and metastasis (spread) from cancer of anus or vulva may result in swollen lymph nodes, not related to a lymphoma. Lymph node enlargement developing in a known case of cancer will indicate its spread. If it develops in a case already treated for cancer, it will indicate recurrence of the disease.
  • Melanoma is one of the types of skin cancer which may cause swelling of the lymph nodes around the affected area.

Drugs and Vaccines

  • Medication. The side effects of certain drugs may cause lymph node enlargement although this is not a common occurrence. Some drugs that may contribute towards lymph node swelling include certain medicines for gout (like allopurinol),  epilepsy and bipolar disorder (like phenytoin and carbamazepine), infections like penicillin for bacterial infections and pyrimethamine for malaria and sulfonamides (sulfa drugs). Lymph node enlargement due to drugs is more likely to be generalized.
  • Certain vaccinations such as MMR (measles, mumps and rubella) and typhoid vaccination may also cause generalized lymph node enlargement.

Systemic

  • Patients with known systemic diseases such as rheumatoid arthritis, sarcoidosis or systemic lupus erythematosus (SLE/SLE) may develop a swollen lymph nodes later in the disease. It is usually generalized.
  • Lymphadenitis or inflammation of the lymph nodes resulting in swelling of the nodes is common in children and is often due to a local or generalized infection, usually viral in origin.  Tuberculous lymphadenitis may be seen more often in developing countries, with generalized lymph node enlargement indicating widespread dissemination of the disease.

Please note that any information or feedback on this website is not intended to replace a consultation with a health care professional and will not constitute a medical diagnosis. By using this website and the comment service you agree to abide by the comment terms and conditions as outlined on this page

  • Hi Chris. This definitely needs further investigation because an inguinal hernia would not usually present with red patches, blisters and swollen lymph nodes. Many of these symptoms sound like an infection. The inguinal hernia may be a separate condition. December was almost 6 months ago so rather look at the current symptoms as entirely different condition and let a doctor reassess him.

  • Bobby Wall

    Dr. Chris. I have a spot that is where my thigh meets my groin area, not in the i finial area, but closer to the bottom of my left butt cheek. Doesn’t cause me discomfort unless I really push on it and I discovered it through self examination. No fever, sweats, rashes or anything like that. Feels a bit swollen, almost a little spongy like. I feel something similar on the other side, but it is much smaller and there is no pain or tenderness. I know this area is loaded with lymphnodes, just curious if I should be worried or have it checked out?

  • Bobby Wall

    Dr Chris, I recently found what feels like a smaller, spongy lymphnode in the area where my thigh meets my groin/bottom left butt cheek. It does not cause me discomfort unless I push on it and then it is just a bit tender. It does move when I press on it. I have a similar one on the other side that is much smaller and is not tender at all to the touch. No fever, rashes, chills or anything like that. A little diarrhea (somewhat loose stool) but nothing that can’t be chalked up to eating some fatty and fast foods the last few days. No weight loss or appetite issues either. Just curious to see if I should have it checked or not?

  • Chris

    Thank you very much

  • Hi Bobby. This may not be something to worry about immediately. However, you should have it checked up if it persists for more than a few days, if it is increasing in size, starts oozing or becomes very painful and if you develop a fever. It’s good to cautious and inquire about these types of symptoms but don’t leave it unattended for too long. It may be a lymph node or it may not be. There is no way of saying for sure until a doctor examines it.

  • Bobby Wall

    Met with the Doc, he said its nothing to worry about. Said it is probably just a cyst. Said to keep an eye on it to see if it gets bigger or starts to cause discomfort. Other than that, he said don’t worry about it.

  • Thanks for the feedback Bobby.

  • Asoka Jayasinghe

    Hello Dr.Chris,

    About a year ago, I felt a pain in my upper groin area, like a muscle was pulled. I felt around my groin and found two bulges, not very big but definitely concerning. I went to the doctor and eventually they discovered that it was a swollen lymph node. They gave me antibiotics and eventually the swelling and pain went away.

    Now in the past week, I have another swollen lymph node in the same area. Its painful but not terribly so. The doctor is doing blood work now but says I shouldn’t have anything to worry about since I don’t have other symptoms.

    My question is, is is odd that I have swollen lymph again in the same area? My doctor said that if it was something serious then last year my symptoms would have gotten worse, not better.

    I am just worried that this is happening again.

    Thanks for your help!

  • Asoka Jayasinghe

    Hello Dr.Chris,

    About a year ago, I felt a pain in my upper groin area, like a muscle was pulled. I felt around my groin and found two bulges, not very big but definitely concerning. I went to the doctor and eventually they discovered that it was a swollen lymph node. They gave me antibiotics and eventually the swelling and pain went away.

    Now in the past week, I have another swollen lymph node in the same area. Its painful but not terribly so. The doctor is doing blood work now but says I shouldn’t have anything to worry about since I don’t have other symptoms.

    My question is, is is odd that I have swollen lymph again in the same area? My doctor said that if it was something serious then last year my symptoms would have gotten worse, not better.

    I am just worried that this is happening again.

    Thanks for your help!

  • Brittany

    Hello,
    I have been experiencing an excruciating pain in my lower right pelvic and thigh area for five years. I have had an appendectomy and a cholysysectomy as a result. In addition, I have also had a pelvic laparascopy done a couple of weeks ago. None of the surgeries have eliminated my pain nor additional symptoms. The extreme pain is located in the lower right pelvic area extends down my right thigh into my lower right back is associated with fatigue, diarrhea, constipation, bloating, nausea, loss of appetite, inability to concentrate because I also have had a swollen sore gland underneath the left side of my jaw. Its been going on for a month now and I can feel the soreness in my ear especially when I yawn it hurts a little. I am in so much pain and a whole slew of other things. I recently had a CT Scan which came back with free fluid in the pelvis along with a swollen inguinal lymph node. I am pretty sure this is what the cause is and many doctors in the past have not even mentioned this being a possibility because they just bounce me around between an obgyn and a GI doctor. I am so tired of living a life of pain and sickness. I honestly am so disappointed by the healthcare system for not coming up with a diagnosis after FIVE LONG YEARS…I also have had really bad boils or blisters on the outside of the vagina, my mom stated that they appeared as ingrown hair bumps but they were filled with sometimes puss and blood and were very sore and sometimes would open up if popped by accident. it would be hard to sit sometimes because they hurt…weird thing is that I dont get them anymore but I used to in the past like 2-3 years ago. I am in the process of getting a doctor to follow up to go over results and next steps regarding the ct scan results but I need some help to guide me through because I want the lymph nodes removed if that is what the problem is and I hate going through fifty million tests just to find out I wasted time and money with no answer and no diagnosis

  • Hi Brittany. Your case seems long and complicated and there is not much more we can shed on the matter. You have been attended to by several doctors, including specialists, and they would have checked for disc degeneration. HIV infection and diabetes and so on which are some of the conditions that could explain most of your symptoms. You should follow up with your doctor for further clarity on the matter.

  • Chris

    Thanks for replying he has gotten insurance finally and sees a dr soon thank u

  • bernadette bell

    Hello,
    I have 3 swollen lymph nodes, one on the left side by my public line and 2 on the right near my thigh. They are painful and move a little when touched. I also have pain in my buttocks and up the sides of my genital area. I am very concerned because I am not sick, so very odd for them to be swollen. I am just waiting until I get on my husband’s insurance, we signed up 2 days ago. Please any advice. It hurts to sit ugh

  • wa vinton

    Hi Dr.Chris,I have been having inflammation in my buttock and back for a little over two years now and at times results to weight loss, recently I have been experiencing swollen nodes in my buttock while the inflammation persist and like previously I also experience the inflammation in certain parts of my Hand like elbows and back of my hands and when these inflammation occurs that portion of the body builds up heat,I have sought the attention of medicals doctors but no known cause have been found.I have had HIV/AIDS test taken numerous times in the past due to this symptoms but all these test came back negative. What would possibly be the cause from your medical point of view.

  • Donna Ruhl

    The other day I found two painful lumps in my groin area.I pinched one and felt it pop. I tried to pop the other but nothing happened.Now it’s three times the size,It’s right on my panty line and painful as hell. Is this a boil or a lymph node? I was thinking ingrown hair. And I haven’t the foggiest idea where the lymph nodes are located.