Lymph nodes work as filters in our bodies, trapping infection and illness to prevent them from spreading. These smooth, pea-sized glands can become enlarged, swelling as big as a grape or tennis ball.
Swollen lymph nodes in the groin in women have many of the same causes as in men. A lower body infection, such as yeast infection or athlete’s foot, is the most likely cause.
A low-grade infection caused by injury while shaving your legs or pubic hair can also cause your groin lymph nodes to swell.
Sexually transmitted infections (STIs) and cancer are other possible causes.
This article covers all of these potential causes, other symptoms to be aware of, and when to see a doctor.
Swelling tends to occur in the lymph nodes closest to the area of infection. The groin lymph nodes, also called inguinal nodes, are usually affected by infection or illness in the lower body.
The following are the most common causes of swollen groin lymph nodes in women:
- vaginal yeast infection, which is caused by an overgrowth of the fungi candida
- bacterial vaginosis, a common infection that occurs when too much of a certain kind of bacteria alters your vaginal pH balance
- low-grade infection from shaving your pubic hair or legs
- athlete’s foot, a fungal skin infection that begins with a scaly rash between the toes
- urinary tract infection (UTI), an infection that can affect any part of your urinary tract
- cellulitis, a potentially serious skin infection that most often affects the lower legs and can spread to the bloodstream if not treated
- gonorrhea, a common STI that often causes no symptoms, but can damage the female reproductive system if not treated
- genital herpes, an STI caused by the herpes simplex virus that often begins with flu-like symptoms and swollen groin lymph nodes
- syphilis, a serious STI that starts with a sore and develops in stages with the potential to cause damage throughout the body if not treated
- HIV, the virus that causes AIDS and starts with flu-like symptoms and swollen lymph nodes two to four weeks after initial infection
Though other causes are more common, cancer can cause swollen lymph nodes in the groin in women and men.
Cancer in the pelvis, back, and lower extremities can spread to your inguinal lymph nodes. Examples of such cancers include:
Swollen lymph nodes can also be caused by lymphoma and leukemia, though these types of cancers are more likely to cause generalized lymphadenopathy. This is when more than one area of lymph nodes, such as the armpits and groin, swells.
Other conditions that can cause more than one area of swollen lymph nodes are:
- systemic viral infections, such as chickenpox, mononucleosis, and tuberculosis
- autoimmune disorders, such as lupus, Sjögren’s syndrome, and rheumatoid arthritis
- certain bacterial and parasitic infections, such as Lyme disease, cat scratch disease, and toxoplasmosis
A lymph node is considered abnormal when it measures larger than 1 centimeter (0.4 inches). Along with swollen lymph nodes in your groin, you may experience other symptoms depending on what’s causing the swelling.
If your swollen groin nodes are caused by infection, you may also have one or more of the following symptoms:
- skin rash
- skin abscess
- infected cut
- skin redness and warmth
- vaginal itching
- vaginal discharge
- groin pain
- blisters or ulcers on or around the genitals
- pelvic pain
- painful urination
- cloudy urine
Warning signs of cancer include:
To diagnose the cause of swollen lymph nodes in the groin, a doctor will begin with reviewing your medical history, including information about your sexual practices.
They’ll want to know how long your lymph nodes have been swollen and any other symptoms you’re experiencing.
The next step is a physical exam to check the nodes for:
The doctor may also check for lymphadenopathy and other signs of injury or infection.
Other tests your doctor may ask for include:
- a pelvic exam, which includes a visual and physical examination of your reproductive and sexual organs
- a pap test to check for cell changes and abnormal cells in the cervix
- STI tests, which can include swabs, blood, or urine tests
- urinalysis to check for UTI and other infections
- blood tests to check for infection or signs of certain cancers
- imaging tests, such as an ultrasound or CT scan to view your abdomen, pelvis, and groin
- lymph node biopsy, if other tests don’t find the cause and to rule out cancer
Treatment depends on the underlying cause of swollen lymph nodes.
When an infection causes swollen lymph nodes, treatment can include one or a combination of the following, depending on the type of infection:
- topical antibiotics
- over-the-counter (OTC) antifungal cream
- OTC yeast infection treatments
- oral antibiotics
- IV antibiotics for severe infections
- antiviral drugs for genital herpes
- antiretroviral therapy (ART) for HIV
If cancer is the cause of your swollen lymph nodes, a number of factors help determine treatment, including the type of cancer and stage, your age, and your overall health.
Cancer treatment may include:
Any new groin lump should be evaluated by a doctor, especially if the lump is hard and fixed in place or it’s been present for more than two weeks.
See a doctor right away if:
- your swollen lymph nodes appeared for no obvious reason
- there’s a chance you’ve been exposed to an STI
- your swollen lymph nodes are accompanied by persistent fever, night sweats, or unexplained weight loss
- you have signs of a serious infection, such as a high fever, rapid heart rate, and breathing
Most of the time, swollen lymph nodes in the groin in women are caused by a lower body infection. This can be a mild skin infection, caused by damage or injury to your skin when shaving your legs or bikini area, to a more serious infection caused by an STI.
Cancer can also cause your inguinal nodes to swell, but it’s a far less common cause. Talk with your doctor if you have concerns about a swollen lymph node. They can help determine the cause.