Kidney Stones: Symptoms, Causes and Emergency Care

Introduction

Kidney stones are hard deposits made from minerals and salts in urine ^[2,7]. They can form in one or both kidneys ^[2]. Stones vary greatly in size and shape ^[2].

Some stones stay in a kidney without causing symptoms ^[6,7]. Others cause severe pain when they enter a ureter ^[6,7]. A ureter is a tube that carries urine from a kidney to the bladder.

A trapped stone can block urine flow ^[6]. Urine may then back up and reduce the kidney’s ability to filter waste ^[6]. A blocked kidney may also face a higher risk of infection or injury ^[2,4].

This guide explains kidney stone symptoms, causes, treatment and when to seek emergency care. It also covers kidney stone pain, tests, prevention, and key warning signs.

Overview: What Kidney Stones Are and How They Form

How crystals develop in the urinary tract

Kidney stones form when urine becomes concentrated ^[4,7]. They can also form when urine has high levels of substances that can turn into crystals ^[1,4]. These substances include calcium, oxalate, uric acid, phosphate, and cystine ^[1,4].

Low citrate levels may also increase stone risk ^[4]. Citrate is a substance in urine that helps limit crystal growth. Urine that is too acidic may also promote certain stones ^[4].

Small crystals can form and stick together ^[1]. They may grow into stones over several weeks or months ^[1]. A stone may be smooth, rough, or jagged ^[2].

Some stones are as small as a grain of sand ^[2]. Others may become much larger ^[2]. Kidney stones are also called renal calculi, nephrolithiasis, or urolithiasis ^[7].

A stone may stay inside a kidney without causing clear symptoms ^[6,7]. Symptoms often start when the stone moves or enters a ureter ^[7]. The ureter may tighten around the stone and cause severe kidney stone pain ^[6].

Common types of kidney stones

The type of stone depends on the material that forms it ^[1,3]. The main types are:

• Calcium stones: These are the most common type ^[1,10]. Many contain calcium and oxalate ^[1,10].
• Uric acid stones: These may form when urine is too acidic ^[10]. They can occur in people with gout, obesity, or some metabolic conditions ^[10].
• Struvite stones: These are linked to urinary tract infections ^[10]. They can grow large and block urine flow ^[10].
• Cystine stones: These form from cystine crystals in urine ^[4].

Finding the stone type can help guide prevention ^[3,5]. A clinician may ask you to collect a passed stone ^[3]. A lab can then study what it contains ^[3,5].

How stone size and location affect symptoms

A small kidney stone may pass through the urinary tract without a procedure ^[2,3]. However, even a small stone can cause severe pain ^[6]. Pain often starts as the stone moves through the ureter ^[6].

A larger stone may become trapped in the ureter ^[6]. This can cause urine to back up toward the kidney ^[6]. A blocked stone can limit the kidney’s ability to remove waste ^[6].

Stone size alone does not show how serious the problem is ^[6]. The stone’s location and the amount of blockage also matter ^[3,6]. Kidney function and signs of infection help guide treatment as well ^[3,5].

Pain may ease before the stone has left the body ^[8]. Seeing the stone or using imaging can confirm that it is gone ^[8].

Symptoms: Kidney Stone Symptoms and Pain Patterns

Common signs of a moving kidney stone

Kidney stone symptoms may begin when a stone enters the ureter ^[6,7]. Symptoms can start quickly and become intense ^[6,7].

Common kidney stone symptoms include:

• Sharp pain in the side, back, lower belly, or groin ^[4,6].
• Pain that becomes stronger and weaker in waves ^[6].
• Blood in the urine, which is called hematuria ^[4].
• Pain or burning while passing urine ^[7].
• A frequent or urgent need to urinate ^[7].
• Nausea or vomiting during severe pain ^[3,7].
• Trouble passing urine when a stone causes a blockage ^[6].

Blood may make the urine look pink, red, or brown ^[7]. However, blood is not always easy to see ^[4,5]. A urine test may find blood that is not visible ^[4,5].

Some small stones cause no symptoms ^[6]. They may pass through the urinary tract without being noticed ^[6]. Other small stones can cause extreme pain while moving ^[6].

Where kidney stone pain occurs

Kidney stone pain often starts in the back or side ^[6,7]. It may occur below the ribs ^[7]. The pain can move toward the lower belly or groin ^[4,6].

The painful area may change as the stone moves ^[7]. Pain often comes in waves because the ureter tightens around the stone ^[6]. It may ease for a short time and then return ^[6].

Some people cannot find a comfortable position during an attack ^[7]. Kidney stone pain can be severe even when the stone is small ^[6]. A larger stone may cause no pain while it remains in a kidney ^[6].

Pain strength does not always show the stone’s size or danger ^[6,8]. Less pain also does not prove that the stone has passed ^[8]. Medical tests may still be needed after symptoms improve ^[5,8].

Symptoms that can resemble other conditions

Side, belly, or groin pain may have more than one cause. Urinary pain, urgency, nausea, and blood in the urine are not enough to confirm a stone. A medical exam and tests can help find the cause ^[5].

Fever or chills are serious signs when they occur with possible stone symptoms ^[7]. They may point to an infection with a blocked urinary tract ^[3,4]. This condition needs emergency assessment ^[3,4].

Repeated vomiting may lead to dehydration ^[3]. A person who cannot keep fluids down may need hospital care ^[3]. The hospital may provide fluids through a vein, known as IV fluids ^[3].

Causes: Kidney Stone Causes and Risk Factors

Low urine volume and crystal-forming substances

Kidney stones form when urine has too little water ^[4,7]. This makes stone-forming substances more concentrated ^[4,7]. High levels of these substances can lead to crystal growth ^[1,4].

Calcium, oxalate, uric acid, cystine, and phosphate can form crystals ^[1,4]. The crystals may join and grow into solid stones ^[1]. The exact cause can differ by stone type ^[1].

Low fluid intake can reduce urine volume ^[7]. Drinking more fluid may make urine less concentrated ^[3,5]. This may help lower the risk of another stone ^[3,5].

Urine chemistry also affects stone growth ^[4]. Urine that is too acidic may support some types of stones ^[4,10]. Low citrate may also make stones more likely to form ^[4].

Diet, health conditions, and medications

Diet can affect the risk of kidney stones ^[4,7]. Body weight and health conditions may also play a role ^[7]. Some supplements and medicines can add to the risk ^[4,7].

High sodium intake may be addressed in a stone prevention plan ^[5]. Some foods, such as spinach, contain oxalate ^[1]. Vitamin C supplements can also provide oxalate ^[1].

Diseases of the small intestine may raise the risk of some calcium stones ^[1]. Obesity and metabolic conditions are linked to uric acid stones ^[7,10]. Some urinary infections can lead to struvite stones ^[10].

Certain medicines may change stone risk in some people ^[4,7]. However, people should not stop prescribed medicine on their own. A clinician can review medicines and supplements during a stone assessment.

Family history and repeat stones

Some kinds of kidney stones can run in families ^[1]. A clinician may ask about stones in close family members. A past stone is also useful information during an assessment.

Kidney stones can return after a first episode ^[9]. Tests can help find factors that raise the risk of repeat stones ^[3,5]. The results may guide changes in food, fluids, or medicine ^[3,5].

A lab can test a passed or removed stone ^[3,5]. This is called stone analysis. It shows the stone’s chemical makeup ^[3,5].

Blood tests may find high calcium or uric acid levels ^[5]. They can also help check kidney health ^[5]. A 24-hour urine test measures substances in urine over a full day ^[5].

These tests can help create a more personal prevention plan ^[3,5]. General advice may not fit every type of stone. Follow-up testing can show whether risk factors are still present ^[5].

Diagnosis and Treatment for Kidney Stones

Exams, urine tests, blood tests, and imaging

Diagnosis often begins with a health history and physical exam ^[5]. The clinician may ask where the pain began. They may also ask whether it moves or comes in waves.

The clinician may review past stones and other health conditions. Medicines and supplements may also be reviewed. This information can help guide the choice of tests.

Urine testing can find blood and other signs of urinary problems ^[4,5]. Blood tests can measure calcium and uric acid ^[5]. Blood tests also help check how well the kidneys work ^[5].

Imaging shows whether a stone is present ^[5]. It can also show the stone’s size and location ^[5]. Imaging may help find a blockage that needs treatment ^[3,5].

A CT scan can find stones in the urinary tract ^[5]. CT stands for computed tomography. Some CT scans can find very small stones ^[5].

Ultrasound may also be used to look for kidney stones ^[5]. It uses sound waves to make images inside the body. The best test depends on the person and the medical setting.

CT, ultrasound, blood tests, urine tests, and stone analysis may help diagnose kidney stones ^[3,5]. They may also find factors that raise the risk of another stone ^[3,5]. These results guide kidney stone treatment and follow-up.

Home care and medicines for small stones

Small stones may pass without a procedure ^[2,3]. Still, kidney stone treatment must fit the person’s condition. The plan depends on stone size, location, symptoms, and kidney function ^[3,5,6].

Signs of blockage or infection also affect the treatment plan ^[3,4]. A clinician should guide care when a stone is suspected. Home symptoms alone cannot show the full risk.

A clinician may advise drinking plenty of liquids ^[3]. This advice applies when the person can drink and keep fluids down ^[3]. People with severe vomiting may need IV fluids instead ^[3].

Pain medicine may help while a small stone passes ^[3,7]. A clinician may prescribe pain relief ^[3]. Some people may use an over-the-counter option with medical guidance.

An alpha blocker may be prescribed in selected cases ^[5]. This drug relaxes parts of the urinary tract ^[5]. It may make it easier for some stones to pass ^[5].

A clinician may ask the person to strain their urine ^[3]. This can help catch the stone after it leaves the body. A lab can then test the stone and guide prevention ^[3,5].

Small stones may pass without a procedure ^[2,3]. However, pain relief does not prove that a stone has passed ^[8]. Imaging may be needed to confirm that it is gone ^[8].

Procedures for blocked or larger stones

A larger stone may need urgent treatment ^[3]. Treatment may also be needed when a stone blocks urine flow ^[3,6]. Severe pain or failure to pass can also lead to a procedure ^[3,6].

Vomiting and dehydration may require hospital care ^[3]. The person may receive fluid through an IV ^[3]. An infected blockage needs urgent treatment ^[3,4].

Common procedures include:

• Shock wave lithotripsy: Shock waves break the stone into smaller pieces ^[5]. Those pieces may then pass in urine ^[5].
• Ureteroscopy: A clinician places a thin tool into the urinary tract ^[5]. The tool can help find, break, or remove the stone ^[5].
• Percutaneous nephrolithotomy: A surgeon removes a large stone through a small opening in the back ^[4,5].

The procedure choice depends on stone size, type, and location ^[3]. The amount of blockage also matters ^[3,5]. Symptoms and overall health help guide the decision ^[3,5].

A urologist is a doctor who treats urinary tract problems. This doctor can explain which procedure may be suitable. Small stones may not need surgery, but blocked stones may need quick care ^[3,6].

When to See a Doctor: Emergency Care and Prevention

Kidney stone emergency symptoms

Fever or chills with a suspected blocked stone may mean the urinary tract is infected ^[3,4]. An infection behind a blockage needs emergency evaluation ^[3,4]. Do not wait at home for the stone to pass.

Seek emergency care for possible kidney stones with:

• Fever or chills ^[7].
• Severe pain that cannot be controlled ^[3].
• Repeated vomiting or dehydration ^[3].
• Trouble passing urine due to a possible blockage ^[6].
• Signs of infection with side, back, or groin pain ^[3,4].

A blocked stone can cause urine to back up toward the kidney ^[6]. This can limit the kidney’s ability to filter waste ^[6]. Larger stones or blocked stones may need urgent treatment ^[3].

Emergency care may include pain control and IV fluids ^[3]. Testing can show the stone’s location and check kidney health ^[5]. An urgent procedure may be needed if the urinary tract is blocked ^[3,5].

When to contact a clinician promptly

Contact a clinician for new, severe pain in the side or back. Visible blood in urine also needs medical assessment. Painful or urgent urination may occur with a kidney stone ^[4,7].

Several problems can cause these symptoms. Imaging and lab tests can help show whether a stone is present ^[5]. They can also help detect blockage or changes in kidney function ^[3,5].

Do not judge the problem only by the level of pain ^[6,8]. A small stone can cause severe pain ^[6]. A larger stone may cause few symptoms while it stays in the kidney ^[6].

Contact a clinician if symptoms improve but you have not seen the stone pass. Pain relief does not always mean the stone is gone ^[8]. Imaging can help confirm whether it remains in the urinary tract ^[8].

Hydration, diet, and follow-up prevention

Prevention often starts with enough fluid to make urine less concentrated ^[3,5]. A healthcare professional can suggest a suitable fluid plan. The right plan may depend on health needs and stone history.

Reducing sodium may be part of a prevention plan ^[5]. Other food changes should match the stone type and test results ^[3,5]. Broad food limits may not address the cause of every stone.

Some people may need medicine to prevent repeat stones ^[5]. The choice depends on test results and stone type ^[3,5]. A clinician can explain the goal of the medicine.

Follow-up may include blood tests or urine collections ^[5]. Imaging may also help track stones or check whether one has passed ^[5,8]. Stone analysis can make prevention advice more specific ^[3,5].

Conclusion

Knowing kidney stone symptoms, causes, treatment and when to seek emergency care can help prevent harm. Small stones may pass without a procedure ^[2,3]. Yet treatment decisions must account for size, location, symptoms, and kidney function ^[3,5,6].

Blockage and infection are also key concerns ^[3,4]. Fever or chills with a suspected blocked stone may signal an infected urinary system ^[3,4]. This requires emergency evaluation ^[3,4].

Seek urgent care for uncontrolled pain, repeated vomiting, dehydration, or signs of an infected blockage ^[3,4,7]. Mild cases still need proper medical guidance. Testing and follow-up can guide safe treatment and help prevent future stones ^[3,5].