Your Health A-Z


Flank Pain

Flank pain is a pain that is either on the left or the right side of the flank/side of back.

Other Names

Side pain


Flank pain is a pain that is either on the left or the right side of the flank/side of back.



  • Kidney infection (pyelonephritis)
    Kidney infection is associated with acute, severe pain with fever or chills and blood in the urine (haematuria) that can be microscopic (not visible to the naked eye) or macroscopic (visible to the naked eye). You should seek medical advice immediately, as you cannot cure this condition on your own at home.

The best treatment is intravenous (injected) antibiotics, as well as strong anti-inflammatories.



  • Kidney stone (nephrolithiasis)
    Kidney stones are mineralised stones present in the renal (kidney) system. When the stone passes into ureter (duct from the bladder), it is called ureterolithiasis. The majority of stones are calcium oxalate or calcium phosphate. Other stones can be magnesium ammonium, uric acid or cysteine stones.


The first symptom of a kidney stone is often the acute onset of colicky abdominal pain that starts at the flank and radiates to the groin, scrotum or labia. It is often associated with nausea and vomiting.

It cannot be treated at home and you should immediately consult your doctor, in order for him/her to do an abdominal CT scan, to assess if the stone can be passed through the urinary tract or if it will have to be removed surgically.



  • Kidney abscess
    The first symptom of this is usually pain over a long period of time and can feel like a strained muscles in the flank/back. Accompanying symptoms are tiredness, malaise, as well as a low grade fever. If you suspect that you are suffering from this condition, you should consult your physician, in order to have an ultrasound done. These abscesses are usually treated with percutaneous (through the skin) drainage of the abscess, as well as strong oral antibiotics.




  • Shingles (Herpes Zoster)
    Shingles is a latent reaction of chicken pox. This virus lies dormant in the dorsal ganglia (nerves in the back) until it is reactivated by stress, trauma, medication and other possible systemic infections. The rash is confined to a specific dermatome (skin region that is serviced by a specific nerve) on the face. It can therefore, appear on any side of the face. Flank pain with a one-sided rash is also common. This condition is extremely painful and cause systemic effects, i.e. malaise, fever and general sweating.


You should consult your doctor for treatment. He will prescribe tricyclic, as well as anti-viral therapy that includes topical anti-viral cream and acyclovir orally.



  • Muscle spasm
    You can experience severe and acute flank pain when you strain your back muscles. It can either be one-sided or on both sides. This pain can be treated at home with anti-inflammatories, bed rest, as well as a cold compress to the specific area.




  • Spinal arthritis
    The first symptom of this is severe, chronic back, as well as flank pain. You have to consult a doctor, in order to have an X-ray and a CT scan of your lower back done, in order to confirm the diagnosis and to start with the correct treatment. Treatment at home involves strong anti-inflammatories, bed rest and a cold compress.




  • Disk disease
    Disk pain can present with acute lower back and flank pain, radiating to the hip and the knee. There can also be numbness on the affected side’s leg. It is extremely important to contact your doctor, in order to have a CT scan of the lower back done and to start with the correct treatment. This can include bed rest for a long period of time or the removal of the damaged disc.


Written by Dr Anrich Burger, MB ChB (Stell)

The information provided in this article was correct at the time of publishing. At Mediclinic we endeavour to provide our patients and readers with accurate and reliable information, which is why we continually review and update our content. However, due to the dynamic nature of clinical information and medicine, some information may from time to time become outdated prior to revision.

In the interest of our patients, in accordance with SA law and our commitment to expertise, Mediclinic cannot subscribe to the practice of online diagnosis. Please consult a medical professional for specific medical advice. If you have any major concerns, please see your doctor for an assessment. If you have any cause for concern, your GP will be able to direct you to the appropriate specialists.