Kidney Pain: Location, Causes, and When To Get Help

It can be very difficult to separate back pain from kidney pain.

This is because your kidneys sit in your mid-back below your ribs on either side of your spine. 

Kidney pain has several causes, including infection, injury, or other medical problems like kidney stones or cancer.

If your kidneys are causing pain, there is a problem, and you should see your primary care clinician. 

This article talks about kidney pain and where you may feel the pain. It also discusses why your kidneys may be in pain and how your medical provider will diagnose the problem.

Lastly, read through some commonly asked questions about kidney pain. 

What Is Kidney Pain?

Kidney pain can feel like a dull ache that gets more intense when someone presses on the area.

You may also feel sharp pains in your back, side, or groin. 

In most cases, the pain is felt only on one side of your body, but some kidney problems can affect both kidneys at the same time.

When both kidneys are involved, you feel pain on both sides. 

Sometimes kidney pain can be accompanied by other symptoms such as:

• Fever
• Bloody urine
• Pain when urinating
• Body aches and chills
• Fatigue
• Nausea and vomiting

Where Is Kidney Pain Located?

Your kidneys sit in the area called your flank, which is positioned mid-back, under your rib cage, on either side of your spine. When your kidneys hurt, you feel the pain in this flank area.

Depending on the issue, you may also feel pain in your sides and groin.

There are several other organs in this area, along with muscles and bones. Your medical provider can help determine where the pain is originating. 

Kidney pain vs. back pain

Here are some clues for telling the difference between kidney and back pain. 

Kidney Pain	Back Pain
Felt in your back, deep in your body	Usually felt in the lower back
Feels dull and grows in intensity when pressed	Feels sharp and may shoot down one leg
Can be in one or both sides	Gets worse with certain activities (bending or lifting)
Doesn’t go away with position changes or rest	May ease when you change position or rest

Causes

Your kidneys are part of your urinary system, which also includes the ureters, bladder, and urethra.

This system is responsible for filtering your blood and creating urine from the waste.

Several problems can arise from the urinary system and affect the kidneys. 

Urinary tract infection (UTI)

A urinary tract infection (UTI) can happen in any part of the urinary tract.

The most common location is in the bladder (bladder infection). 

Burning when urinating is a classic sign of a UTI, as well as needing to pee more frequently.

Usually, these infections are caused by bacteria from the bowel or by holding the urine for too long.

Your medical provider will give you antibiotics and encourage you to drink plenty of fluids to treat a bladder infection.

If you’re experiencing fever, nausea, or vomiting along with this type of pain, please seek in-person care as soon as possible. 

Kidney infection

A kidney infection (pyelonephritis) is another type of urinary tract infection.

Typically, the condition begins in the bladder and, when left untreated, grows into the kidneys as well.

A kidney infection can become a serious medical problem in rare cases, but usually, quick treatment prevents complications.

Symptoms include:

• Kidney pain
• Fever
• Chills
• Pain when urinating

Treatment includes antibiotics and drinking plenty of fluids.

Kidney stones

Kidney stones are small collections of minerals (calcium, oxalate, and phosphorus) that form into pebbles when they are present in high amounts in your urine.

They can be as small as a grain of sand or as large as a pea. Their edges can be jagged or smooth, and they are usually yellow or brown. 

Tiny kidney stones can pass through your urinary system without complication, but larger ones may cause pain and blockage.

Symptoms include:

• Sharp pain in your back, side, lower abdomen, or groin
• Pink, red, or brown blood in your urine
• Constant urge to urinate
• Difficulty urinating or only able to pass in small amounts
• Bad-smelling, cloudy urine
• Fever
• Chills
• Nausea and vomiting

Small stones may not require treatment, but larger ones may need medical intervention.

Your medical provider may give you pain medication and ask you to drink lots of fluids to try and flush the stone out.

If the stone is causing a blockage, a urologist (urinary tract specialist) may need to break up the stone and remove it. 

Kidney cyst

A cyst is a fluid-filled sac that is typically harmless. They can grow as you age or be caused by a disease, such as polycystic kidney disease. 

Polycystic kidney disease (PKD) runs in families and causes large cysts to grow in the kidneys, disrupting their function.

At first, you may not experience any symptoms but as they get larger, they can cause back pain, headaches, and bloody urine. 

At this point, there is no cure for PKD, but lifestyle changes and other treatments can help decrease complications. 

Hydronephrosis

Hydronephrosis is when your kidney swells because there is a backup of urine. 

The backup of urine can be caused by several conditions:

• Malformation of the urinary system at birth
• Blocked ureter
• Kidney stones
• Cancer in the urinary tract
• Enlarged prostate

Symptoms include:

• Flank pain
• Nausea and vomiting
• UTI
• Fever
• Pain when urinating
• Frequent urination with feelings of urgency

Treatment depends on what the cause is.

Sometimes antibiotics are given to clear an infection, and sometimes a stent (little tube) is placed in the ureter to restore urine flow. 

Injury

Certain injuries such as a fall, accident, or sports injury can hurt the kidneys.

This is also called kidney trauma or kidney bruising. The pain can be mild to severe, depending on the extent of the damage. This type of injury is different from acute kidney injury (AKI). 

AKI is when there is a sudden (within hours) loss of kidney function (this used to be called acute kidney failure).

There are many different causes, including infection, blockage, blood clots, autoimmune disease, illicit drug use, and several other reasons.

Symptoms can include:

• Flank pain
• Nausea and vomiting
• Metallic taste in mouth
• Bruising easily
• High blood pressure
• Fatigue
• Changes in urinating pattern

Treatments focus on finding the underlying cause and treating that to stop kidney damage. 

Kidney cancer

At first, kidney cancer may not cause any pain. However, you may feel pain in your back or lower abdomen as it progresses.

You may also get a fever and see that you have blood in your urine. However, these symptoms are common with other kidney issues and don’t mean you have kidney cancer.

Treatment includes surgery, chemotherapy, radiation, immunotherapy, and targeted therapy.

There are also clinical trials going on for new treatments. 

Diagnosis

After your medical provider has completed a physical exam and reviewed your current medications, a few tests help determine what is going on with your kidneys. 

Blood tests

Blood tests are able to see if your body is fighting an infection or if you are dehydrated; these also give an idea of how well your kidneys are functioning. 

Creatinine is a waste product that your kidneys remove from your blood. If your creatinine level is elevated it may mean your kidneys are not functioning as they should. 

Glomerular filtration rate (GFR) is a common blood test that tells how well the kidneys are filtering the blood.

Urine tests

A urinalysis checks to see if there is blood, white blood cells (too many could indicate infection), proteins, and other chemicals in your urine. 

A urine culture checks your urine for bacteria and determines which antibiotic would be best to treat your infection.

Imaging

Computed tomography (CT) scans can show if there is a kidney stone, where it’s located, and if it’s causing a blockage. It can also look for the reasons why the stone formed. 

Ultrasound of the kidneys can reveal if there is a blockage, kidney stone, or tumor.

When To See a Medical Provider

See your primary medical professional if you experience the following symptoms:

• Persistent low back pain
• Fever
• Chills
• Blood in your urine
• Pain when you urinate

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