10 Warning Signs and Symptoms of Kidney Stones You Should Know

Kidney stones, medically known as nephrolithiasis, are hard mineral and salt deposits that form inside your kidneys. These crystalline structures can range in size from a grain of sand to a golf ball and can cause excruciating pain when they move through the urinary tract. Understanding the symptoms of kidney stones is crucial for early detection and prompt medical attention.

Approximately 1 in 10 people will experience kidney stones at some point in their lives, with men being more susceptible than women. While small stones may pass through the urinary system without causing significant discomfort, larger stones can block the flow of urine and cause severe symptoms. This comprehensive guide will help you recognize the warning signs of kidney stones, understand their causes, and learn preventive measures.

1. Severe Pain in the Side and Back (Renal Colic)

The most characteristic symptom of kidney stones is intense, debilitating pain that typically begins in the side and back, below the ribs. This pain, known as renal colic, is often described as one of the most severe types of pain a person can experience, comparable to childbirth.

The pain occurs when a stone moves from the kidney into the ureter, the narrow tube connecting the kidney to the bladder. As the stone travels through this confined space, it causes the ureter to spasm and contract, resulting in waves of severe pain. The discomfort may radiate from your side and back to your lower abdomen and groin area, following the path of the urinary tract.

Key characteristics of kidney stone pain:

• Comes in waves with varying intensity
• Pain fluctuates as the stone moves
• Can last from minutes to hours
• Often worsens at night or early morning
• No position provides complete relief

2. Pain During Urination (Dysuria)

When a kidney stone reaches the junction between the ureter and bladder, or when it’s positioned in the urethra, you may experience sharp, burning pain during urination. This symptom, called dysuria, indicates that the stone is in the lower portion of the urinary tract and may be close to passing.

The pain during urination can feel like a sharp stabbing or burning sensation that intensifies as you urinate. This occurs because the stone irritates the sensitive lining of the urinary tract. Some people describe it as feeling like they’re passing shards of glass. This symptom can sometimes be confused with a urinary tract infection, but it’s an important indicator that a stone may be present.

3. Blood in Urine (Hematuria)

Hematuria, or blood in the urine, is one of the most common symptoms of kidney stones, occurring in about 85-90% of cases. The blood appears because the sharp edges of the stone scratch and damage the delicate lining of the urinary tract as it moves through.

The blood in your urine may appear in different ways:

• Gross hematuria: Visible blood that makes urine appear pink, red, or brown
• Microscopic hematuria: Blood cells only visible under a microscope during urinalysis

The amount of visible blood doesn’t necessarily correlate with the severity of your condition. Even a small amount of blood can discolor urine significantly. The color may vary throughout the day depending on your hydration level and the stone’s movement. If you notice any blood in your urine, it’s important to seek medical evaluation.

4. Frequent and Urgent Need to Urinate

Kidney stones can cause a persistent, urgent need to urinate more frequently than normal. This symptom becomes particularly pronounced when the stone reaches the lower urinary tract, near the bladder. The stone’s presence irritates the bladder wall, creating a constant sensation that you need to empty your bladder, even when you’ve just urinated.

You may find yourself rushing to the bathroom multiple times per hour, only to pass small amounts of urine each time. This urgency can be disruptive to daily activities and sleep patterns. The frequent urination is your body’s attempt to flush out the stone, but it can also be a sign of bladder irritation or infection that sometimes accompanies kidney stones.

5. Cloudy or Foul-Smelling Urine

Healthy urine is typically clear and has a mild odor. However, when you have kidney stones, your urine may appear cloudy or murky and emit a strong, unpleasant smell. This symptom can indicate the presence of pus in the urine, a condition called pyuria, which may signal an infection.

Cloudy urine associated with kidney stones may result from:

• Presence of white blood cells fighting infection
• Bacteria in the urinary tract
• Mineral crystals and debris from the stone
• Concentrated urine due to dehydration

The foul smell often indicates bacteria growth, which is a serious concern. Kidney stones combined with a urinary tract infection can lead to serious complications and require immediate medical attention.

6. Nausea and Vomiting

Nausea and vomiting are common accompanying symptoms of kidney stones, affecting approximately 50% of patients. These symptoms occur due to shared nerve connections between the kidneys and the gastrointestinal tract. When your kidneys are in distress from a stone, these nerve pathways can trigger your digestive system to react.

The severity of nausea often correlates with the intensity of pain. As pain waves intensify, you may experience increased nausea or sudden vomiting episodes. This can be particularly problematic because it may prevent you from staying hydrated, which is crucial for helping stones pass. Persistent vomiting can also lead to dehydration and electrolyte imbalances, potentially requiring medical intervention.

7. Fever and Chills

While fever is not a typical symptom of uncomplicated kidney stones, its presence is a serious warning sign that demands immediate medical attention. Fever and chills accompanying kidney stone symptoms may indicate that you’ve developed a urinary tract infection or, more seriously, a kidney infection (pyelonephritis).

Warning signs that require emergency care:

• Temperature above 100.4°F (38°C)
• Shaking chills or rigors
• Fever combined with severe pain
• Confusion or altered mental state

A kidney infection with a blocked urinary tract is a medical emergency that can lead to sepsis, a life-threatening condition. If you experience fever along with other kidney stone symptoms, seek immediate medical care.

8. Inability to Pass Urine or Reduced Urine Output

If a kidney stone is large enough or positioned in a way that completely blocks the ureter, you may find yourself unable to pass urine or notice a significant decrease in urine output. This symptom, called anuria (no urine) or oliguria (decreased urine), is a medical emergency.

Complete blockage prevents waste products and toxins from being eliminated from your body, causing them to build up in your bloodstream. This can quickly lead to serious complications including:

• Acute kidney injury
• Hydronephrosis (kidney swelling)
• Permanent kidney damage if left untreated
• Buildup of dangerous toxins in the blood

If you experience severe pain combined with little or no urine output for several hours, this requires immediate emergency medical attention.

9. Restlessness and Inability to Find a Comfortable Position

People with kidney stones often exhibit distinctive restless behavior, constantly shifting positions in an attempt to find relief from the pain. Unlike other abdominal conditions where staying still helps, kidney stone pain typically makes sufferers feel compelled to move continuously.

This restlessness is so characteristic that doctors often use it as a diagnostic clue. You might find yourself:

• Pacing back and forth
• Constantly changing positions in bed
• Alternating between sitting, standing, and lying down
• Rocking or moving your body rhythmically
• Unable to sit still during medical examinations

This behavior occurs because the pain is internal and movement-related, coming in waves as the stone shifts position in the urinary tract. No external position can truly alleviate the discomfort, leading to this characteristic restlessness.

10. Pain Radiating to the Groin and Lower Abdomen

As a kidney stone progresses down the ureter toward the bladder, the location of pain typically shifts and radiates downward. This radiating pain follows the anatomical path of the urinary tract, moving from the back and side toward the lower abdomen, groin, and even into the genital area.

In men, the pain may radiate to the testicles or tip of the penis. In women, the pain may radiate to the labia. This lower pain often indicates that the stone is moving closer to the bladder and may be approaching the point where it will pass out of the body.

The radiation pattern of pain can help doctors determine approximately where the stone is located in the urinary tract, which aids in treatment planning and predicting whether the stone might pass on its own.

What Causes Kidney Stones?

Understanding what causes kidney stones can help you recognize risk factors and take preventive action. Kidney stones form when your urine contains more crystal-forming substances than the fluid in your urine can dilute. Multiple factors contribute to stone formation:

Dehydration: The most common cause of kidney stones is insufficient fluid intake. When you don’t drink enough water, your urine becomes concentrated, allowing minerals and salts to crystallize and stick together. People living in warm climates or those who sweat heavily are at higher risk.

Dietary Factors: Certain dietary habits significantly increase kidney stone risk:

• High sodium intake causes more calcium to be excreted in urine
• Excessive animal protein consumption increases uric acid levels
• High oxalate foods like spinach, nuts, and chocolate can contribute to calcium oxalate stones
• Insufficient calcium intake paradoxically increases stone risk
• High sugar and fructose consumption

Medical Conditions: Several health conditions increase kidney stone risk:

• Obesity and metabolic syndrome
• Digestive diseases like inflammatory bowel disease and chronic diarrhea
• Hyperparathyroidism causing elevated calcium levels
• Gout resulting in uric acid stones
• Urinary tract infections
• Renal tubular acidosis

Family History and Genetics: If someone in your family has had kidney stones, you’re more likely to develop them as well. Certain genetic disorders also affect the way your body processes minerals and can predispose you to stone formation.

Medications and Supplements: Some medications and supplements can increase stone risk, including certain diuretics, calcium-based antacids, and vitamin C supplements in high doses. Always consult with your healthcare provider about potential side effects.

How to Prevent Kidney Stones

Prevention is the best approach to managing kidney stones, especially if you’ve had them before. Studies show that about 50% of people who’ve had kidney stones will develop another within 5-7 years without preventive measures. Here are evidence-based strategies to reduce your risk:

Stay Well Hydrated: This is the single most important preventive measure. Aim to drink enough fluids to produce at least 2-2.5 liters of urine per day. Water is the best choice, though lemonade can be beneficial as citrate helps prevent stones. Your urine should be light yellow or clear. If it’s dark yellow, you need to drink more.

Modify Your Diet:

• Reduce sodium: Limit sodium intake to less than 2,300 mg per day
• Moderate protein: Avoid excessive animal protein; aim for appropriate portions
• Eat calcium-rich foods: Don’t restrict dietary calcium; it actually helps prevent stones by binding to oxalate in the digestive tract
• Limit oxalate-rich foods: If you form calcium oxalate stones, moderate intake of high-oxalate foods
• Reduce sugar: Limit added sugars and fructose

Maintain a Healthy Weight: Obesity is a significant risk factor for kidney stones. Losing weight through healthy diet and exercise can reduce your risk. However, avoid high-protein, low-carbohydrate diets as they may increase stone risk.

Increase Citrus Intake: Citrate, found in lemons and limes, helps prevent stone formation by binding to calcium and preventing crystal formation. Consider drinking lemon water throughout the day.

Monitor Your Medications: Discuss with your doctor whether any of your medications might increase stone risk and whether alternatives are available.

Know Your Stone Type: If you’ve passed a stone, have it analyzed to determine its composition. This information helps your doctor recommend specific dietary and lifestyle modifications tailored to your stone type.

Regular Medical Check-ups: If you’re at high risk for kidney stones, regular monitoring including urine tests can help detect problems early and allow for preventive interventions.

Frequently Asked Questions

What do kidney stones feel like?

Kidney stones typically cause severe, sharp pain in the side and back below the ribs that comes in waves. The pain often radiates to the lower abdomen and groin. Many people describe it as one of the worst pains they’ve ever experienced, comparable to childbirth. The pain intensity varies as the stone moves through the urinary tract.

What are the first signs of kidney stones?

The first sign is usually sudden, severe pain in the back or side below the ribs. This may be accompanied by blood in the urine (making it pink or red), nausea, and a frequent urge to urinate. Some people notice their urine becomes cloudy or foul-smelling before the pain starts.

How do you know if you have kidney stones?

Common indicators include severe pain in your side and back, blood in urine, painful urination, frequent urination, nausea, and vomiting. However, definitive diagnosis requires medical imaging such as CT scans, ultrasound, or X-rays, along with urine and blood tests performed by a healthcare provider.

What causes kidney stones in women?

Women develop kidney stones from the same causes as men: dehydration, diet high in sodium or protein, obesity, certain medical conditions, and family history. However, women may be at increased risk during pregnancy due to hormonal changes and increased calcium excretion. Urinary tract infections are also more common in women and can contribute to certain types of stones.

How long does it take for a kidney stone to pass?

The time varies depending on the stone’s size and location. Small stones (less than 4mm) typically pass within 1-2 weeks, though it can take up to 4-6 weeks. Stones between 4-6mm may take longer and have about a 50% chance of passing on their own. Larger stones rarely pass without medical intervention.

Can kidney stones go away on their own?

Yes, many kidney stones pass naturally through the urinary tract without medical intervention. Small stones (less than 5mm) have a high likelihood of passing on their own with adequate hydration and pain management. However, larger stones or those causing complications may require medical procedures to remove them.

When should I see a doctor for kidney stones?

Seek immediate medical care if you experience severe pain that prevents you from sitting still or finding a comfortable position, pain accompanied by nausea and vomiting, pain with fever and chills, blood in your urine, or difficulty passing urine. These symptoms may indicate complications requiring urgent treatment.

Are kidney stones dangerous?

While painful, most kidney stones are not dangerous and pass without causing permanent damage. However, they can become dangerous if they cause complete urinary blockage, lead to kidney infection, or result in kidney damage. Complications like these require immediate medical attention. Untreated infected kidney stones can lead to sepsis, a life-threatening condition.

How are kidney stones different in women compared to men?

The symptoms are generally similar, though women may sometimes confuse kidney stone pain with gynecological issues. Women are less likely to develop kidney stones overall, but pregnancy and urinary tract infections can increase risk. The pain radiation pattern in women may extend to the labia rather than the testicles as in men.

What foods should I avoid if I’m prone to kidney stones?

This depends on your stone type, but general recommendations include limiting sodium, reducing animal protein intake, moderating high-oxalate foods (spinach, nuts, chocolate, tea) if you form calcium oxalate stones, and avoiding excessive vitamin C supplements. However, don’t restrict calcium-rich foods unless specifically instructed by your doctor, as adequate dietary calcium actually helps prevent stones.

References:

• Mayo Clinic – Kidney Stones
• National Institute of Diabetes and Digestive and Kidney Diseases – Kidney Stones
• National Kidney Foundation – Kidney Stones
• Johns Hopkins Medicine – Kidney Stones
• Urology Care Foundation – Kidney Stones