Lump in groin

Your groin is the area between your thighs and abdomen and is where your genitals are located. There are many different causes for a lump in your groin, some of which are serious.

What causes a groin lump?

A lump in your groin can vary in size and shape and may not always be painful. You can have one lump or several, and some lumps may move, break open, form sores or ulcers. Lumps can also be red, purple or skin-coloured.

Groin lumps can arise from any tissue in your groin area, from your skin down into deeper tissues and the bones in this area.

Causes of groin lumps include:

Cysts

Cysts are non-cancerous lumps that can cause discomfort or pain, especially when they grow in size. It is important not to squeeze or pop a cyst as this can cause infection. Similarly, if a cyst bursts under your skin, it can cause the surrounding tissue to become infected.

Signs of an infected cyst include swelling, redness, tenderness and warmth on touch.

Swollen lymph nodes

An infection, such as a cold or flu, or an illness, such as mononucleosis, can cause the lymph nodes in your body to swell. The lymph nodes most likely to swell include those in your armpits, either side of your neck and your groin.

Causes of swollen lymph nodes

Causes of swollen lymph nodes in your groin include:

• Bacterial vaginosis
• Cancer of your reproductive organs or other nearby organs
• Hodgkin’s lymphoma
• Urinary tract infections (UTIs)
• Vaginal yeast infections
• Sexually transmitted infections (STIs) 

Hernia

A hernia occurs when part of one of your organs, usually your intestines, or abdominal tissue pushes through a weakness in the tissue that is meant to hold it in. There are different types of hernias. Inguinal and femoral hernias cause a large soft lump in your groin area, often at the top of the front or inner side of your thigh. Other symptoms include: 

• A lump in your scrotum
• Abdominal bloating
• Abdominal pain 
• Groin pain or discomfort that worsens on movement
• Nausea or vomiting 

Inguinal hernias

An inguinal hernia occurs when part of your intestines or fatty tissue in your abdomen pushes through a weakness in your lower abdominal muscle wall.

Femoral hernias

A femoral hernia occurs when part of your intestines or fatty tissue in your abdomen pushes through a weakness in your abdominal muscle wall near your inner thigh.

Sexually transmitted infections (STIs)

Certain STIs can make the lymph nodes in your groin swell, causing a lump in your groin. These STIs include chlamydia, gonorrhea, herpes and syphilis.

STIs can also cause a cluster of lumps in your groin, with some lumps breaking open to form sores. 

STIs need to be treated to get better. 

Saphena varix

Saphena varix is caused by swelling of the saphenous vein that passes through your groin. It causes blue-tinged, golf-ball sized lumps that disappear when you lie down. If you have varicose veins, which commonly occur in legs and thighs, you are more likely to develop saphena varix. However, saphena varix is very rare.

Enlarged blood vessels

Enlarged veins or arteries, specifically femoral aneurysms and varicose veins, can cause a lump in your groin.

Femoral aneurysms

Your femoral artery runs from the top of each of your thighs and down each of your legs. A femoral aneurysm occurs when this artery swells due to a weakness in the artery wall. Symptoms include a pulsating lump in your groin, cramping in your groin, numbness in your groin and groin pain that spreads down one leg.

Varicose veins

Varicose veins are swollen, twisted purple veins that bulge from under your skin. They are caused by damaged or weak vein walls. Varicose veins most often occur in legs and thighs. Symptoms include swollen legs and feet, and a heaviness or pain in your legs and feet.

Treatments for groin lumps

If you notice a lump in your groin, you should see your GP as soon as possible. If after three weeks of treatment, your lump persists or worsens, you should see your doctor again. 

Your GP will ask about your symptoms and may perform a physical examination to check if your lymph nodes are inflamed. They may also refer you for blood tests to check for signs of infection. 

Treatment for groin lumps varies depending on the underlying cause. If the cause is swollen lymph nodes, your groin lump may disappear on its own over time. However, if you have an underlying infection, your doctor may prescribe antibiotics. 

Surgery may be needed to remove large or painful cysts, and to repair a hernia by pushing the tissue back in and closing or securing the weakness.