Kidney stones (medically known as nephrolithiasis) are hard mineral and salt deposits that form inside your kidneys. They can affect any part of your urinary tract — from the kidneys to the bladder. Kidney stones are one of the most painful medical conditions a person can experience, often described as one of the worst pains imaginable. Understanding the symptoms early is crucial for getting timely treatment and avoiding complications. Whether you’re wondering what do kidney stones feel like, or concerned about kidney stone symptoms in women specifically, this guide covers everything you need to know.
1. Severe Pain in the Back, Side, or Below the Ribs
One of the most hallmark signs of kidney stones is intense, sharp pain in the back or side, just below the ribcage. This type of pain is often referred to as renal colic. Here’s what makes this pain distinctive:
- Location: The pain typically starts in the flank area (the side of the abdomen between the lower ribs and hip), and can radiate downward toward the lower abdomen and groin.
- Intensity: Many patients describe it as one of the most severe pains they’ve ever experienced — often compared to the pain of childbirth or a knife stabbing.
- Pattern: Unlike muscle pain, kidney stone pain tends to come in waves. It may start suddenly, peak in intensity, then ease slightly before returning — often following the movement of the stone through the urinary tract.
- Duration: Each episode of pain can last anywhere from a few minutes to several hours, depending on the stone’s movement.
This is often the very first and most unmistakable sign that something is wrong, and it’s what prompts most people to seek medical care immediately.
2. Pain That Radiates to the Lower Abdomen and Groin
As a kidney stone moves from the kidney down through the ureter toward the bladder, the location of pain shifts accordingly. This traveling pain is a key indicator of kidney stones:
- Pain that begins in the back or flank may gradually move to the lower abdomen, then into the groin or inner thigh area.
- In men, the pain may radiate into the testicles or scrotum.
- In women, the pain may be felt in the labia or inner thigh, which can sometimes be confused with other gynecological conditions.
The shifting nature of the pain often follows the path the stone is taking through the urinary tract, making it a useful clue for diagnosis. This is why tracking where your pain starts and where it moves is helpful information to share with your doctor.
3. Burning Sensation or Pain During Urination
When a kidney stone reaches the junction between the ureter and the bladder — or passes into the urethra — you may experience significant discomfort during urination:
- A sharp, burning, or stinging sensation when urinating (dysuria)
- Pain that can be mistaken for a urinary tract infection (UTI) or bladder infection
- Discomfort that persists throughout or immediately after urination
This symptom often alarms patients because it’s similar to the feeling of a urinary tract infection. However, if it occurs alongside flank pain or blood in the urine, kidney stones are a more likely cause. Only a proper medical evaluation can distinguish between these conditions.
4. Blood in the Urine (Hematuria)
Blood in the urine is a very common symptom of kidney stones and occurs because the stone causes damage or irritation to the lining of the kidney, ureter, or bladder as it passes through. What you might notice:
- Pink, red, or brown-colored urine — the classic visible sign of blood in the urine
- Microscopic hematuria — in some cases, the blood is not visible to the naked eye and can only be detected through a urine test
- The discoloration may come and go depending on the stone’s movement and the degree of irritation
Important: Blood in the urine should always be evaluated by a healthcare professional, as it can be a sign of several serious medical conditions beyond kidney stones, including infections or tumors.
5. Nausea and Vomiting
Many people with kidney stones experience nausea and vomiting, which are believed to result from two main mechanisms:
- The nerve connection: The kidneys share nerve pathways with the gastrointestinal tract (via the celiac plexus), so intense kidney pain can trigger nausea and vomiting as a reflex response.
- Urinary obstruction: When a stone blocks the flow of urine, it can cause a backup of pressure that leads to nausea, similar to how other forms of severe abdominal pain affect the digestive system.
Vomiting can sometimes be severe enough to prevent patients from keeping fluids down, which can lead to dehydration — a dangerous complication that worsens the condition. If vomiting is persistent, medical care should be sought immediately.
6. Frequent and Urgent Need to Urinate
An increased urgency or frequency of urination is a common symptom, particularly when the stone has moved closer to the bladder. Patients often report:
- A persistent and sudden urge to urinate, even when the bladder is not full
- Needing to urinate more often than usual throughout the day and night
- Only passing small amounts of urine each time despite the strong urge
This symptom is similar to what is experienced with bladder infections or an overactive bladder, which can make diagnosis confusing without proper testing. The key differentiator is usually the presence of other symptoms such as flank pain or blood in the urine.
7. Cloudy or Foul-Smelling Urine
Healthy urine is typically clear and has a mild odor. When kidney stones are present — especially if they have led to an infection — you may notice changes in the appearance and smell of your urine:
- Cloudy urine: This can indicate the presence of pus (pyuria), which is a sign of infection in the urinary tract.
- Strong, foul, or unusual odor: This is another potential indicator of a urinary tract infection that may have developed as a complication of the stone blocking urine flow.
- Urine that appears dark or concentrated, which may also indicate dehydration.
Cloudy or foul-smelling urine should not be ignored, as it may signal an infection that requires prompt antibiotic treatment under a doctor’s supervision.
8. Difficulty Urinating or Decreased Urine Output
In some cases, particularly when a kidney stone causes a significant blockage in the ureter, you may notice difficulty urinating or a noticeably reduced amount of urine. This is more serious and can indicate:
- A stone that is causing a partial or complete obstruction of urine flow
- Increased pressure and swelling in the kidney (hydronephrosis)
- Potential kidney damage if the obstruction is not relieved promptly
A sudden drop in urine output combined with severe pain is a medical emergency. This symptom should prompt immediate medical attention to prevent long-term kidney damage.
9. Fever and Chills
Fever and chills are not typical symptoms of an uncomplicated kidney stone on their own. However, when they occur alongside other kidney stone symptoms, they are a serious red flag indicating that an infection may have developed:
- A blocked ureter from a kidney stone can trap bacteria and cause a kidney infection (pyelonephritis)
- In severe cases, the infection can spread to the bloodstream, causing sepsis — a life-threatening condition
- Fever above 38°C (100.4°F) combined with kidney stone symptoms requires immediate emergency medical care
Never ignore a fever when you suspect you have kidney stones. This combination of symptoms is considered a urological emergency.
10. Restlessness and Inability to Find a Comfortable Position
Unlike some types of abdominal pain where lying still provides relief, kidney stone pain is often so intense and unpredictable that patients find it nearly impossible to get comfortable:
- Patients often pace, shift positions, or writhe in discomfort trying to relieve the pain
- No particular body position consistently alleviates the pain
- This restlessness is a classic behavioral sign of renal colic and is often noted by emergency room physicians as a diagnostic indicator
This inability to find comfort is partly due to the intermittent nature of the pain and the spasms caused by the ureter trying to push the stone through. It can be emotionally and physically exhausting for the patient.
11. Groin Pain or Testicular Pain in Men
In men, kidney stone pain can radiate downward and specifically affect the groin or testicular area. This can lead to significant confusion and anxiety:
- Sharp or aching pain in one or both testicles that has no apparent physical cause in the scrotum itself
- Discomfort in the groin that may feel like a pulled muscle or hernia
- The pain originates from referred nerve signals as the stone travels down the ureter toward the bladder
Men who experience testicular pain without any visible injury or swelling should consider kidney stones as a potential cause, especially if accompanied by flank pain or changes in urination.
12. Kidney Stone Symptoms in Women: Pelvic Pain and Confusion with Other Conditions
Kidney stone symptoms in women can sometimes be more difficult to identify because the pain can mimic or overlap with other common conditions such as ovarian cysts, appendicitis, endometriosis, or pelvic inflammatory disease. Specific considerations for women include:
- Pelvic pain: Women may feel pain in the pelvic region that radiates from the flank downward, which can be confused with menstrual cramps or gynecological pain
- Pain during the menstrual cycle: Overlapping symptoms can make it harder to distinguish kidney stone pain from dysmenorrhea
- Urinary symptoms: Burning during urination and frequent urges may be attributed to a UTI, which is more common in women — delaying the correct diagnosis
- Referred pain: Pain may extend to the inner thigh or labia, making localization difficult
Women who experience any combination of flank pain, blood in the urine, and urinary changes should seek a proper medical evaluation to rule out kidney stones, even if the pain pattern seems to match another familiar condition.
Main Causes of Kidney Stones
Understanding what causes kidney stones can help you identify your risk and take preventive action. The most common causes include:
- Dehydration: Not drinking enough water is the leading cause. Concentrated urine allows minerals to crystallize and clump together.
- High-sodium diet: Excess sodium increases the amount of calcium your kidneys must filter, raising the risk of calcium-based stones.
- High-protein diet: Diets rich in animal protein can increase uric acid levels and reduce citrate, a natural stone inhibitor.
- Oxalate-rich foods: Foods like spinach, nuts, chocolate, and tea are high in oxalate, which can bind with calcium to form calcium oxalate stones — the most common type.
- Obesity and metabolic syndrome: Excess body weight is associated with changes in urine chemistry that promote stone formation.
- Family history and genetics: If a parent or sibling has had kidney stones, your risk is significantly higher.
- Certain medical conditions: Conditions such as hyperparathyroidism, gout, renal tubular acidosis, Crohn’s disease, and recurrent urinary tract infections can increase risk.
- Certain medications and supplements: Some medications and high doses of certain vitamins (like vitamin C) can increase stone-forming substances in urine. Always consult your doctor about medication side effects.
How to Prevent Kidney Stones
The good news is that kidney stones are largely preventable with the right lifestyle habits. Here are evidence-based prevention strategies:
- Stay well hydrated: Drinking enough water is the single most effective way to prevent kidney stones. Aim for enough fluids to produce at least 2 liters of urine per day. Your urine should be pale yellow or clear.
- Reduce sodium intake: Limit processed foods, canned goods, and added salt to lower urinary calcium levels.
- Moderate animal protein: Reduce consumption of red meat, poultry, eggs, and shellfish, as excess protein raises uric acid and lowers urinary citrate.
- Limit oxalate-rich foods (if prone to calcium oxalate stones): Reduce intake of spinach, rhubarb, beets, nuts, and chocolate, or always eat them alongside calcium-rich foods to reduce absorption.
- Do not avoid calcium: Contrary to popular belief, adequate dietary calcium (from food sources) actually helps reduce stone risk by binding oxalate in the gut. However, excessive calcium supplements may increase risk — consult your doctor.
- Maintain a healthy body weight: Regular exercise and a balanced diet help regulate the metabolic factors that contribute to stone formation.
- Limit sugar-sweetened beverages: Sodas and fruit juices high in fructose have been linked to increased kidney stone risk.
- Regular medical check-ups: If you have a history of kidney stones, regular urine and blood tests can help monitor levels of stone-forming substances and allow your doctor to recommend appropriate dietary or medical interventions.
Frequently Asked Questions (FAQ)
What are the first signs of kidney stones?
The earliest signs of kidney stones typically include sudden, severe pain in the back or side (flank), pain that radiates to the lower abdomen or groin, and blood in the urine. Some people also notice nausea or a burning sensation during urination before the full-blown pain begins.
What does kidney stone pain feel like?
Kidney stone pain is most commonly described as an intense, cramping, wave-like pain in the back, side, or lower abdomen. It is often compared to the pain of childbirth or being stabbed. The pain may come and go in waves and typically does not improve with changes in body position.
How do you know if you have kidney stones?
The most telling signs are sudden severe flank or back pain, blood in the urine, nausea, vomiting, and changes in urination. However, a definitive diagnosis requires medical imaging (such as a CT scan or ultrasound) and urine tests performed by a healthcare professional.
Are kidney stone symptoms different in women?
The core symptoms are similar for both sexes, but women may experience pelvic pain that can be confused with gynecological conditions such as ovarian cysts or endometriosis. The urinary burning may also be mistaken for a UTI, which is more common in women, potentially delaying the correct diagnosis.
Can you have kidney stones without pain?
Yes. Small kidney stones may pass through the urinary tract without causing noticeable symptoms — these are sometimes called “silent” kidney stones. They may only be discovered incidentally during imaging for another condition. However, once a stone becomes large enough to obstruct urine flow, pain typically develops.
When should I see a doctor for kidney stone symptoms?
You should seek immediate medical care if you experience severe, unrelenting pain, fever with chills, blood in the urine, vomiting that prevents you from keeping fluids down, or difficulty urinating. These symptoms — especially fever combined with pain — can indicate a serious infection requiring urgent treatment.
How do kidney stones form?
Kidney stones form when the urine becomes too concentrated with certain minerals and salts — most commonly calcium, oxalate, and uric acid. When these substances are present in higher amounts than the urine can dilute, they begin to crystallize and stick together, gradually forming a solid stone over time.
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