Kidney Pain: Symptoms, Treatment, and Causes

Kidney pain definition and facts
- The function and purpose of the kidneys are to remove excess fluid and waste products from the body.
- The kidneys are organs that are located in the upper abdominal area against the back muscles on both the left and right side of the body.
- Kidney pain and back pain can be difficult to distinguish, but kidney pain is usually deeper and higher in the and back located under the ribs while the muscle pain with common back injury tends to be lower in the back.
- Common causes of kidney pain are mainly urinary tract infections, kidney infections, and kidney stones. However, there are many other causes of kidney pain, including penetrating and blunt trauma that can result in a "lacerated kidney."
- If a woman is pregnant and has kidney pain, she should contact her doctor.
- Symptoms of kidney pain may include
- Kidney pain can be on the left, right, or both sides.
- Causes of kidney pain are diagnosed with the patient's history, physical examination, and lab tests, including blood, pregnancy, and urine tests. A CT scan or MRI of the abdomen and pelvis may be ordered.
- Treatment for the cause of kidney pain depends upon the underlying cause, but in general, ibuprofen (Motrin), ketorolac (Toradol), and/or acetaminophen (Tylenol) are used for pain. Antibiotics are usually required if the underlying cause is a bacterial infection.
- Some people can pass a kidney stone spontaneously that resolves kidney pain; however, other people may need surgery.
- Kidney pain can be prevented by avoiding those situations that are the underlying causes of kidney infection and/or kidney damage.
- The prognosis for someone with kidney pain depends upon the cause, and the majority of patients can have a good outcome when treated quickly and appropriately.

What are the kidneys?
The kidneys are two organs whose major functions are to remove waste products and excess fluid from the body and to produce hormones that regulate blood pressure, red blood cell production, acid regulation and to influence calcium, sodium, potassium, and another electrolyte metabolism.
Where are the kidneys located?
The kidneys are bean-shaped organs (about 11 cm x 7 cm x 3 cm) that are located against the back muscles in the upper abdominal area. They sit opposite each other on both the left and right side of the body; the right kidney, however, sits a little lower than the left to accommodate the size of the liver.

What is the function of the kidneys?
The excess waste products and excess fluid are removed when the kidneys produce urine that is excreted from the body. Moreover, the kidneys play an important role in the regulation of the body's salt, potassium, and acid content.
The kidneys also produce hormones that stimulate the production of red blood cells that help regulate blood pressure and help control calcium and electrolyte metabolism in the body.

What are the first signs and symptoms that are associated with kidney pain?
Symptoms associated with kidney pain (also termed renal or flank pain) are discomfort (acute or chronic), aches, or sharp pain that occurs in the back between approximately the lowest rib and the buttock. Depending on the cause of the pain, it may radiate down the flank to the groin or toward the abdominal area. Some individuals may develop symptoms and signs such as:
- Fever
- Painful urination (dysuria)
- Blood in the urine
- Nausea
- Vomiting
- Dizziness
- Constipation or diarrhea
- Rash
- Fatigue
- Chills
Other symptoms and signs that may occur if the kidney function is increasingly compromised are a
- metallic taste in the mouth,
- bad breath,
- swelling and shortness of breath.
Depending on the underlying cause, kidney pain may occur on the left or right side. Sometimes it can occur on both sides of the back; traumatic kidney injury (kidney laceration) may cause the above symptoms, but mild damage may initially have no symptoms. Severe kidney lacerations can cause abnormal blood pressure and pulse, and shock.
Kidney pain itself is a symptom that may happen due to problems or diseases of the kidney or its associated structures, including the ureters or bladder. However, other diseases may mimic kidney pain, but are not actually due to the kidneys, for example,
- muscle strains in the back,
- spinal problems (fracture, abscesses),
- rib pain,
- pleuritis,
- radiculitis,
- retroperitoneal fibrosis,
- shingles,
- aortic abdominal aneurysm,
- gynecological problems, and
- many other causes.
Although kidney pain often occurs on one side of the back, it can occur on both sides at the same time and may radiate toward the abdomen or groin.
Pain that occurs suddenly is sharp, severe, and may increase and decrease in waves is often due to kidney stones in the ureters of the kidneys. Pain caused by kidney stones is termed renal colic.

What are some examples of kidney conditions and diseases that cause pain?
Many of the causes of kidney disease that lead to kidney pain (also termed flank pain) are due to acquired underlying diseases that may acutely or chronically affect kidney function. Other diseases are present at birth. Some people may be born with an abnormality that is genetically determined that affects the kidneys.
Kidney pain or flank pain can be acute, relatively constant, and sharp. This is termed "renal colic." This kind of pain is usually seen when a kidney stone or other problem blocks the tube (ureter) that drains the kidney. However, other processes can cause chronic dull aching with occasionally sharp kidney pain. Some of the causes of kidney pain or flank pain are as follows:
- Urinary tract infections (UTI)
- Bladder infection (cystitis)
- Kidney infections (pyelonephritis)
- Hydronephrosis
- Kidney stones (nephrolithiasis and/or ureterolithiasis)
- Kidney cancer
- Anything that compresses the kidney (for example, a large tumor)
- Glomerulonephritis
- Blood clots in the kidneys (renal vein thrombosis)
- Polycystic kidney disease (congenital)
- Congenital malformations in the renal system resulting in complete or partial blockage of urine flow
- Drugs or toxins that harm kidney tissue (for example, pesticide exposure or chronic use of medications such as ibuprofen [Advil, Motrin, and others])
- Kidney pain during pregnancy
- Kidney bleeding (hemorrhage) such as from penetrating trauma or blunt trauma ("kidney laceration")
- End-stage renal disease