Painful Thigh Lump: Causes
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A painful bump or lump on the thigh can also appear red, small or large, and often be located on the inner thigh. Most commonly, bumps on the inner thigh are caused by infected ingrown hairs, boils, cysts, or a swollen lymph node. Other causes include trauma to the thigh or abnormal cell growth like lipoma.
Painful lump on thigh symptoms
It's not uncommon to notice lumps and bumps on different parts of your body, but finding a new lump, especially a painful one, can be alarming. However, there are many potential causes for painful thigh lumps; while most causes are not serious and easily treatable, some require medication or the advice of a medical professional.
Common characteristics of a painful thigh lump
A lump or swelling located just under the skin in your thigh can be:
- Large or small
- Soft or firm
- Mobile: This means it moves when you touch or press it.
- Fixed: This means it feels stuck in its location.
Common accompanying symptoms of a painful thigh lump
These lumps can also be associated with:
Duration of symptoms
A thigh lump may be a short- or long-term occurrence depending on the cause.
- A thigh lump may last for only a few days before resolving on its own or you may notice it persist for a week or more.
- You may notice that a thigh lump that is persistent seems to grow over time as well.
Are painful thigh lumps serious?
Painful thigh lumps can vary in severity and can be evaluated by the following.
- If it is self-resolving: A small thigh lump that resolves on its own is typically not serious.
- If you also have a fever: A large lump that is associated with redness, pain, and numbness that does not seem to be resolving should be seen by a medical professional, especially if you also have a fever.
- If it is growing or fixed: Lumps that are growing and feel fixed should be evaluated by a medical professional.
What causes a painful lump or knot on the thigh?
There are many potential causes for painful thigh lumps. Typically, these are due to certain skin conditions. Less commonly, thigh lumps can be a symptom of abnormal growths. How serious the painful thigh lump is is dependent on the cause.
There are many parts of the superficial skin that can become infected, causing a painful thigh lump, as well as the possibility of an infection within your body, fought by lymph nodes.
- Infected hair follicles: The areas where each of your hair strands grow out of your skin are called follicles. When a follicle gets infected, usually due to a bacterial or fungal cause, it can lead to folliculitis, defined by areas of red, painful, swollen skin.
- Cellulitis: This is a condition in which an open cut (visible or not) on your skin becomes infected due to exposure.
- Abscess: A skin infection can eventually turn into an abscess which is a pocket of pus.
- Lymph node enlargement: Your lymph nodes are small glands where the cells that fight off infections live. In reaction to the infection in and around your thigh area, they can grow in size and appear as a thigh lump.
Painful thigh lumps can also be caused by trauma. If you remember bumping your thigh into something, being bitten by an insect, or coming into contact with a sharp object, your thigh lump may be your body's reaction to the trauma.
Abnormal cell growth
Your body is made up of many cells that are constantly growing and dividing. Usually, your body is good at making sure the cells are growing normally, but sometimes you might develop abnormal growths. Thigh lumps can be due to the following types of abnormal cell growth:
- Abnormal fat cell growth
- Abnormal bone, cartilage, muscle or tendon cell growth
- Abnormal skin and hair follicle cell growth
This list does not constitute medical advice and may not accurately represent what you have.
Lipoma is a word that translates as "fatty tumor," but a lipoma is not cancer. It is simply a growth of fat between the muscle layer and the skin above it.
The exact cause is not known. The condition does run in families and is associated with other unusual syndromes such as adiposis dolorosa, which is similar. Lipomas most often appear after age 40.
Symptoms include a soft, easily moveable lump beneath the skin, about two inches across. A lipoma is painless unless its growth is irritating the nerves around it. They are most often found on the back, neck, and abdomen, and sometimes the arms and upper legs.
It is a good idea to have any new or unusual growth checked by a medical provider, just to make certain it is benign.
Diagnosis is made through physical examination, biopsy, and imaging such as ultrasound or CT scan.
Most of the time, treatment is not necessary unless the lipoma is unsightly or is interfering with other structures. It can be removed through surgery or liposuction.
Top Symptoms: skin-colored groin bump, marble sized groin lump, small groin lump
Symptoms that always occur with lipoma: skin-colored groin bump
Urgency: Wait and watch
A dermatofibroma is a common skin growth that usually appears on the lower legs, but may appear anywhere on the body. These growths are benign (noncancerous). Dermatofibromas are most common in adults and are rarely found in children.
Symptoms include a hard, raised growth that is red, pink, ..
A skin abscess is a large pocket of pus that has formed just beneath the skin. It is caused by bacteria getting under the skin, usually through a small cut or scratch, and beginning to multiply. The body fights the invasion with white blood cells, which kill some of the infected tissue but form pus within the cavity that remains.
Symptoms include a large, red, swollen, painful lump of pus anywhere on the body beneath the skin. There may be fever, chills, and body aches from the infection.
If not treated, there is the risk of an abscess enlarging, spreading, and causing serious illness.
Diagnosis is made through physical examination.
A small abscess may heal on its own, through the body's immune system. But some will need to be drained or lanced in a medical provider's office so that the pus can be cleaned out. Antibiotics are usually prescribed.
Keeping the skin clean, and using only clean clothes and towels, will help to make sure that the abscess does not recur.
Top Symptoms: rash with bumps or blisters, red rash, red skin bump larger than 1/2 cm in diameter, pus-filled rash, rash
Symptoms that always occur with skin abscess: rash with bumps or blisters
Urgency: Primary care doctor
A cyst is a small sac or lump, filled with fluid, air, fat, or other material, that begins to grow somewhere in the body for no apparent reason. A skin cyst is one that forms just beneath the skin.
It's believed that skin cysts form around trapped keratin cells – the cells that form the relatively tough outer layer of the skin.
These cysts are not contagious.
Anyone can get a skin cyst, but they are most common in those who are over age 18, have acne, or have injured the skin.
Symptoms include the appearance of a small, rounded lump under the skin. Cysts are normally painless unless infected, when they will be reddened and sore and contain pus.
Diagnosis is made through physical examination. A small cyst can be left alone, though if it is unsightly or large enough to interfere with movement it can be removed in a simple procedure done in a doctor's office. An infected cyst must be treated so that the infection does not spread.
Top Symptoms: skin-colored armpit bump, marble sized armpit lump, small armpit lump
Symptoms that always occur with skin cyst: skin-colored armpit bump
Urgency: Wait and watch
Severe skin abscess
A skin abscess is an infection of the deeper skin that's typically due to bacteria seen on the skin. Recently, infections are more frequently caused by Staph. Aureus (puts the "staph" in "staph infections"). If the infection begins to spread, urgent treatment is required.
Top Symptoms: fatigue, fever, painful neck lump, marble-size neck lump, pink or red neck bump
Symptoms that always occur with severe skin abscess: pink or red neck bump, red bump
Urgency: Hospital emergency room
Enlarged lymph nodes in the groin
Enlarged lymph nodes occur when the node becomes larger as it fills with inflammatory cells. This often is a result of an infection but can occur without a known cause.
Top Symptoms: groin lump, movable groin lump
Symptoms that always occur with enlarged lymph nodes in the groin: groin lump
Symptoms that never occur with enlarged lymph nodes in the groin: fever, unintentional weight loss, hard groin lump
Urgency: Phone call or in-person visit
How to treat a painful lump or knot on the thigh
As long as your pain is not serious, there are several at-home remedies you can try to alleviate symptoms. If those are not effective, you can consult your physician for further medical treatment.
At-home treatments for a painful thigh lump
Certain at-home treatments are available to combat painful thigh lumps.
- Warm and cold compresses: These can help reduce pain and swelling if your thigh lump is due to an infectious cause or trauma.
- Over-the-counter medications: Non-steroidal anti-inflammatory drugs (NSAIDs) like Advil, Motrin, Naproxen and aspirin can help reduce pain, swelling, and redness because they work by reducing inflammation in your body. Acetaminophen (Tylenol) can also help with pain and fever but does not treat the inflammation.
Medical treatments for a painful thigh lump
If you do not find relief with the measures above and your thigh lump has not resolved, consult your physician. They may recommend the following measures.
- Incision and drainage: If your thigh lump is caused by an infection that has caused a collection of pus under your skin, a medical professional may need to cut a small hole (incision) in the skin overlying the bump in order to drain the pus collection.
- Antibiotics: You may also be prescribed anantibiotic in a pill or cream/ointment form in order to fight the infection if your thigh lump is due to a bacterial or fungal cause.
- Surgery: If your thigh lump is caused by an abnormal growth of cells, your doctor may recommend surgery to remove the lump, assess what kind of cells are causing it, and determine whether the lump is cancerous or not.
When a painful thigh lump is an emergency
Seek immediate medical attention in the emergency room or call 911 for the following:
- Severe or worsening pain and/or swelling
- Redness that is worsening or spreading around the lump
- Sudden loss of sensation
FAQs about painful thigh lump
Why is my thigh lump painful?
The pain you're feeling depends on the cause of the thigh lump. Thigh lumps caused by infection may be painful because the body's immune response is reacting to the infection, and you feel pain because your body is alerting you that something is wrong. If it does not resolve soon, you should seek medical attention.
Why is my pain still persisting after my injury?
If your thigh lump is due to trauma, the pain you're feeling is most likely the aftermath of the damage caused to the area in and around the lump. If your pain doesn't get any better or gets worse, seek the attention of a medical provider.
Will my thigh lump go away on its own?
It depends. If your lump is due to abnormal cell growth, it might stay the same, grow or shrink. If it is caused by infection, it might go away on its own as your body fights it, or it might go away with some over-the-counter anti-inflammatory medication like Advil or Motrin.
Do thigh abscesses ever resolve on their own?
If the infection has caused a collection of pus (an abscess) to form, it might go away, but typically this requires draining by a medical professional. Any lump that persists or grows over time should be seen by a medical provider.
Why is my thigh lump growing?
Your thigh lump may be growing due to fluid collecting in and around the area of the lump. If your thigh lump is due to trauma, you can often experience swelling around the injured area, but this swelling should decrease over time. A thigh lump due to infection may grow as pus collects in the lump under the skin or as lymph nodes enlarge in reaction to the infection. A lump can also grow if abnormal cells are building up, and these cells can either be cancerous or non-cancerous. A thigh lump that is growing rapidly in size or persistently grows should be medically evaluated.
Questions your doctor may ask about painful thigh lump
- What color is the bump?
- Any fever today or during the last week?
- Do you have a rash?
- Is there something coming out of the bump?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
Dr. Maina graduated from Princeton University (BA, 2013) with a degree in psychology and received her medical degree from the University of Pennsylvania Perelman School of Medicine. She is currently a resident physician in Otolaryngology at the University of Pennsylvania affiliated hospitals. After graduating from Princeton, she spent a year researching embryonic gene expression with the Center for Research on Reproduction and Women's Health at UPenn. She also received a grant from the National Institutes of Health to study abnormal innate immune responses and taste-related genes in chronic sinus infections. In her free time, she enjoys cooking, reading, listening to podcasts, and finding new DIY décor projects.
- Skin and Soft Tissue Infections. American Family Physician. 2015;92(6):online. AAFP Link
- Folliculitis and Carbuncles. Massachusetts General Hospital. Mass General Link
- Cellulitis. U.S. National Library of Medicine: MedlinePlus. Updated June 6, 2018. MedlinePlus Link
- Abscess. U.S. National Library of Medicine: MedlinePlus. Updated June 6, 2018. MedlinePlus Link