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What is a Psoas Abscess?

A psoas abscess is a rare but serious infection within the psoas muscle, located near the lower spine. It can cause pain, fever, and difficulty moving. Often resulting from bacterial invasion, it requires prompt medical attention. Intriguingly, its symptoms can mimic other conditions, making accurate diagnosis crucial. How does this stealthy ailment present itself, and what are the implications for treatment? Continue with us to uncover the details.
Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

A psoas abscess is an abscess in one of the psoas muscles which extend from the lower spine into the groin. There are a number of potential reasons for one of these muscles to become abscessed, and it can sometimes be tricky to diagnose an abscess in the psoas muscle, as the symptoms are not necessarily obvious. Fortunately, the prognosis for patients with this problem is very good, especially when intervention is provided early.

A primary psoas abscess occurs when bacteria such as Staph bacteria get into the muscle, creating an area of inflammation and infection which often fills with fluid, including pus. This is most commonly seen in children, although it can appear in people of any age. A secondary abscess occurs when infection elsewhere in the body spreads to this muscle; historically, it was most commonly seen in patients with spinal tuberculosis, also known as Pott's Disease. Today, it is more commonly associated with infections of the bowels, kidneys, or spine.

Lower back pain can be a symptom of a psoas abscess.
Lower back pain can be a symptom of a psoas abscess.

A patient with a psoas abscess can experience pain in the abdomen, groin, or lower back. The patient also usually has a fever, and may experience frequent urination. The pain of the abscess can also cause gait changes, as the patient may favor the leg to avoid aggravating the pain. It is possible to diagnose an abscess with a medical imaging study of the area, in which the area of inflamed tissue will be clearly visible.

A patient with a psoas abscess usually has a fever.
A patient with a psoas abscess usually has a fever.

The first step in treating a psoas abscess is draining it. Historically, this was done with an open surgical procedure, but today, it is more common to insert drainage tubes with the guidance of medical imaging equipment. Along with drainage, a doctor may also provide medications to kill the bacteria in the wound, and patients may also take drugs for pain management if the abscess is extremely painful. If the abscess is very extensive, surgery may be required to debride it, removing dead tissue and cleaning the area.

A doctor will use results from tests to determine a treatment plan with the patient.
A doctor will use results from tests to determine a treatment plan with the patient.

Once the psoas abscess has been managed, a doctor can start to explore the causes. It is important to address the underlying condition behind the abscess, in the case of a secondary abscess, to prevent additional problems for the patient. A doctor may request additional tests, medical imaging studies, and other diagnostic tools to learn more about the patient's condition. If a problem is identified, the doctor can discuss treatment options with the patient.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a TheHealthBoard researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a TheHealthBoard researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

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Discussion Comments


I've been diagnosed with Pott's disease with psoas and epidural abscess in march 2017. I had been on anti tb meds and pain killers since April (6 months now). The weakness and numbness in my limps has stopped since June, but the unbearable pain in my lower back, groin and buttocks are showing no signs of going. Will ct drainage be good for me?


I had a psoas abscess removed with surgery, but the wound is not healing. It's been six weeks. What can be the problem?


I was diagnosed with Potts disease and I was started on medication and in a period of about a month, I developed pain and swelling on my left foot, and my doctor told me it showed a psoas abscess of 13cm. How serious is this one?


A psoas abscess is a serious condition and sometimes undiagnosed. My father suffered from a Psoas Abscess and was admitted to the hospital. The surgeon put a needle to drain out the pus. But within a week his condition deteriorated and he suffered cardiac arrest. In his second week he was put on an artificial respiratory system. His body could not cope and he died within a fortnight of infection.


Is it possible to have an undetected psoas abscess for a number of years? CT, MRI has not shown up anything. Pain is severe.


How long can a Psoas infection be left untreated. I can't be treated or diagnosed for six months due to my specific circumstances unless I fly back to my home country. I feel like I've had some sort of lasting pain (bearable) in my lower abdomen, groin, flank, back, and hip. It is ongoing and has lasted two months now. Is it possible that this might not be Psoas abscess?


After suffering excruciating pain in my neck, I had to have emergency ACDF for cervical spinal abscess that had come from a Psoas abscess I didn’t know I had.

Through this I contracted meningitis and septicaemia and had intensive high dose antibiotics through a drip that was changed every three hours for four weeks.

I was hallucinating for a month with temperature over 40 degrees Celsius. Despite being left with many serious health problems I count myself very lucky to have survived.

I had ignored the gradually increasing pain in my neck, assuming it was a strain and urge anyone with a problem to seek help. I was later told that I had less than 24 hours to live when I was taken in to hospital.


Can dogs get psoas abscesses? My 15 week old puppy is developing an abscess on her vagina. She has very foul breath for as young as she is. Can the psoas abscess evolve to staph in an animal? Can an animal's staph abscess infect a a human? Is MRSA in a dog contagious to a human?


I was diagnosed with a psoas abscess and discitis in July 2012. It took six weeks of unbearable pain and dragging my left leg along with bending over all the time to get diagnosed. I was 36, and seriously fit as I trained seven days a week and was told that it was probably caused by a cut to the chin while playing rugby.

I underwent CT, drainage then IV antibiotics followed by three months of oral antibiotics and continued monitoring even now. I had another MRI as I still am in constant pain my coccyx feels battered and the left leg not as strong as it once was. I am a self-employed electrician with three children, but honestly feel that I won't ever recover to the levels of normality I once had, I would like like to know that I will be O.K., but the doctors don't know.


Can this be set off with a serious back strain through lifting something too heavy?


Wow, there are more of us then I anticipated. My doctors say this is very rare and have no reason why it happens. But I guess they need to look online, consult with other doctors (your doctors) and get a meeting of the minds to find a answer.


My son had a psoas abscess two years ago at the age of 20. He was healthy, active, and had just completed basic training for the military. They have no idea how he got the infection. It started with fever, flu like symptoms for a couple days, then severe abdominal pain. Within a day, he was dragging his left leg.

We went through three ER doctors in five days from the onset of the abdominal pain before anyone would really listen to us and take his symptoms seriously. The kept trying to tell us he had mono. They alluded to him being drug seeking despite negative drug tests and no actual signs of drug use.

By the time they really looked at him and did a real head to toe assessment (as simple as feeling the pulse in his foot- or rather the lack of one), his liver, kidneys, spleen and bowel were affected and the abscess had caused a pseudoaneurysm of his iliac artery. The artery ruptured at home and he almost bled to death.

He went through multiple surgeries, months of antibiotics and had to have an arterial bypass graft connecting the blood supply from his right leg to his left leg. He continues to have problems and they are now looking at an alternative bypass graft in his abdomen because he simply does not have enough blood supply from one artery to adequately supply both legs. He almost died several times and fear he will have life long issues.

We are grateful he is alive and that he has his leg, but please, absolutely take this diagnosis seriously and do not ignore recurrent symptoms.


My seven year old son had a psoas abscess a few months ago and all has returned to normal. His WBC esr are both normal. The only problem is he will have intermittent groin pain in different areas of his groin whenever he does any real exercise. Has anyone else had this problem? The doctor doesn't seem to have any answers.


Not wishing to up the ante here but my Dad has a psoas abscess and it has returned. He was on antibiotic drip for two weeks, antibiotics by tablet for four months and after a month, the symptoms returned. He is now back in hospital on a drip and will stay on antibiotics for the rest of his life. He is 86.

He had a fall before this started. He also had a hip replacement a year before and the infection is around/in that leg.

Interestingly, he first had it between his legs/upper thigh. Now it is on the outer part of the leg, nearer the hip.

Question: Who is the international guru on this? Who has done the latest research? Can anyone help? Cheers, R


I had a psoas abscess 35 years ago when I was 13 years old which they could not diagnose, as it was so rare. It went on so long the pus went into my system which gave me a life time of problems. I can't have children, have had endless operations and now have suffered back and hip pain my entire life.


I am a healthy 66 year old man, with a medical history of prostate cancer (removed and totally clear), shoulder surgery five years ago, back surgery 30 years ago, but no ailments, diseases, or recent surgeries, etc.

In August 2010, due to some soreness, I made an appointment with a pain doctor, who, without an MRI, or referral from specialists, did an epidural injection into the rectal area, plus multiple trigger injections. Almost immediately I was ill and for two days had higher fevers, terrible pain in my lower back and hip area and was rushed to ER at two hospitals, in isolation with a staph infection causing an abscess in my psoas muscle, the hardest muscle in the body.

I was ill and relapsed and spent a total of almost four months in rehab, using walkers, picc lines, etc. About 99 percent of case studies show that this rare event only happens in people with long medical histories, diabetes, recent surgeries, HIV, etc.


It is possible to have to incidents. I had one in the lower groin that caused all kinds of various problems. It was drained via CT and then I developed one on my hip. Do not let the doctor tell you IV or oral antibiotics will get rid of this.

The only success I have had is when it was drained then antibiotics. The second one I spent 35 days on IV antibiotics to find out now I'm going to have to have it drained and then antibiotics for six months. Good luck to you all!


A psoas abscess is rare, in general. No matter where an abscess is in the body, pain is a fair indicator, especially pain that does not resolve, or worsens. The term "intractable pain" is used when acute, or short-term, treatment of pain fails, and intractable pain is a big red flag.

If you search websites, you will find that one can have a normal white blood cell count in deep deep tissues, like the psoas muscle. This can be confusing in making a diagnosis. Add a sedimentation rate, ESR, a simple blood test to a WBC count (usually an indicator of infection) and the ESR (that indicates infection) of greater than normal, plus pain, and there is an infection hiding somewhere until proven otherwise. Hope that helps.

Medicine is interpreting a combination of history, examination of the person and results. The psoas muscle abscess is tricky because it hides, usually until it causes awful pain, and debilitation.

Oh, by the way: the treatment of a psoas muscle abscess includes treating it, from six weeks up to six months because of how deep the psoas is. Be a good historian of any and all possible infections. Psoas can be very serious.


I am still recovering after having a psoas abscess that was treated with a very high dose of IV antibiotics then oral for four weeks. I have to have repeat MRI scans to make sure the abscess is diminishing in size.

Believe you me, if you have one of these things you will not be able to stand up you will be crawling around your house, you will lose weight as i did (a stone and half) and it took three weeks for the consultants to find out what was wrong with me.

As an active road runner and fell runner, and fit for my 52 years. I can't believe that this "silent killer" has reduced me to a state of depression as i am still off work and my fitness levels, well i can just about walk two miles before i get worn out. Rose D.


My husband experienced bad back pain and he was diagnosed with sciatica. Three weeks later a lump start growing in his right lower back, instead of improving with physiotherapy and a chiropractor, he felt worse and worse, until the lump grew as big as a melon.

Fortunately, when he had a high fever and underweight, the doctors called for an ambulance. The diagnosis was a psoas abscess caused by an intermittent appendicitis.


@anon155410: The best is to request a CT scan. This will pick it up.


I suspect I may have a Psoas abscess. I have been active in sport my whole life, but because I am 61 years old I get the feeling that GP's and specialists base their diagnoses on what problems the average 61 year old experiences and that is what they have tested me for.

After I've had every conceivable blood test, ultrasound, scopes, ct scans, etc to test for possible problems with my organs - from my brain, heart, liver, gall bladder, pancreas, kidneys, bladder, appendix, etc, etc, which tests all show normal, I have been reading up on the Psoas muscle - that is the area where my problem (pain) started about six months ago.

Problem is, the pain has now moved to my back as well, and has become unbearable, accompanied by a very bad odor which only I can smell and which is not related to vaginal, urine or stool infections. The odor usually fluctuates with the pain. My worst pain is experienced when I sit for long periods or when I am lying down (sleeping even), but I have relief when I am doing any form of exercise for the duration and an hour or two afterward, then the pain returns with a vengeance.

My own diagnosis that I have a chronic infection which may be caused by pus in the Psoas muscle and which is causing me immense pain and discomfort. Question is who do I approach, short of going through the whole process again which produced nothing. I feel frustrated because I have experienced a unwillingness from doctors to prescribe a course of antibiotics unless they have clinical proof that I have a problem. I can assure you I am not hypochondriacally inclined, but feel the quality of my life has declined from 8 out of 10 to about 3 out of 10! Please help!


My husband suffered severe pancreatitis a year ago. He had to have part of his pancreas removed all due to some medications he was taking for Diabetes 2 (Byetta). This medication made his pancreas explode! This happened in november 2009. After surgery in April 2010, he had five drainage tubes inserted.

Just before Thanksgiving 2010, his final two tubes were removed. Fast forward to today and he was having a lot of pain in his lower back and on his left side of the hip. He was running a fever from 98.8 to 101.9. We had a ct scan done on 1/27/11 only to discover a collection of fluid about 15 cm. We just got back from the hospital were they put a drain tube in due to a Psoas abscess. I had to look that up!

I don't know if his pancreas issues had something to do with the abscess or not. He's had several abscesses and infections from his pancreas issues.


Is it possible after you have one psoas abscess to have another? I had surgery to drain mine on december 15 and got the drain out thursday after christmas and yesterday started having problems with my leg again and the same pain is back!


Does psoas abscess appear as a lump in the groin? Anatomically, why?


My husband developed a psoas muscle abscess following hip surgery. It involved L1 and L2 vertebra and caused discitis and osteomyelitis. He started having problems about three weeks post surgery and MRSA was diagnosed. He received Vanco IV for about three weeks and it was stopped.

It was not until seven months post surgery that it was diagnosed psoas muscle abscess. By that time he had received Vanco IV off and on. He had surgery to clean it out and received Vanco IV for two months and was discharged by the infection MD. By that time the bone was destroyed and he had to have a total hip. He is 66.

He had surgery in August and now has MRSA again. The pain in his back was unbearable and he has been told he will have pain the rest of his life. All of this has landed him in a nursing home because he has to learn to walk again if that is possible.


@christym: If not treated, a psoas abscess can develop staph infection. Staph infections can cause serious problems. That is why early diagnosis is vital. Sometimes, even an ultrasound cannot even locate the abscess. An MRI is often required to develop an accurate diagnosis and treatment plan.

With drainage and proper antibiotic therapy, treatment can be very successful.


Can the psoas abscess be serious?


Suppurative psoas abscess often presents pain in the hip instead of in the abdomen and back. This often creates confusion during the diagnosis. Septic arthritis is often suspected when the hip is the site of pain mentioned by the patient.

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    • Lower back pain can be a symptom of a psoas abscess.
      By: milan2099
      Lower back pain can be a symptom of a psoas abscess.
    • A patient with a psoas abscess usually has a fever.
      By: Ocskay Bence
      A patient with a psoas abscess usually has a fever.
    • A doctor will use results from tests to determine a treatment plan with the patient.
      By: Monkey Business
      A doctor will use results from tests to determine a treatment plan with the patient.
    • A patient with a psoas abscess may experience frequent urination.
      By: arturas kerdokas
      A patient with a psoas abscess may experience frequent urination.
    • A patient with a psoas abscess may experience abdominal pain.
      By: Grafvision
      A patient with a psoas abscess may experience abdominal pain.