Kidney stones do not always cause symptoms right away. A small stone may stay in the kidney without causing pain. Symptoms are more likely when a stone moves, irritates the urinary tract, or blocks the normal flow of urine.
At Florida Kidney Physicians, we encourage patients to pay attention to new or worsening pain, changes in urination, nausea, vomiting, fever, or chills. These symptoms may point to a kidney stone, but they can also occur with urinary tract infection, kidney infection, or other medical conditions that need prompt evaluation.
Pain severity does not always match stone size. A smaller stone can cause severe pain if it blocks urine flow or irritates the ureter, while some larger stones inside the kidney may cause few symptoms.
Symptoms That Can Overlap With Other Conditions
Kidney stone symptoms can overlap with urinary tract infection, kidney infection, appendicitis, gallbladder problems, ovarian or testicular conditions, back problems, and other causes of abdominal or flank pain.
This is why symptoms should be evaluated in context, especially when pain is severe, new, worsening, or associated with fever, vomiting, weakness, or urinary changes.
Pain and Discomfort
Flank Pain: How a Stone Can Cause Severe Side or Back Pain
One of the most common symptoms of a kidney stone is sharp, intense pain in the side or back, often below the ribs. This is sometimes called flank pain.
Pain often begins when a stone blocks or irritates part of the urinary tract. When urine cannot drain normally from the kidney toward the bladder, pressure can build behind the stone. That pressure, along with stretching and spasm of the ureter, can cause severe pain.
The pain may start in the back or side and move toward the lower abdomen or groin as the stone travels. The location of the pain can give the care team clues about where the stone may be, but urine testing, bloodwork, and imaging may be needed to confirm the diagnosis.
Renal Colic: How Ureteral Spasms Cause Wave-Like Pain
Renal colic means pain caused by a blockage or irritation in the kidney or ureter.
Kidney stone pain may come and go in waves because the ureter may tighten or spasm as it tries to move urine and the stone forward. A person may feel temporary relief, followed by another sudden wave of severe pain.
This wave-like pattern can be frightening, especially when the pain is intense. Patients should seek medical care if the pain is severe, recurring, or associated with nausea, vomiting, fever, chills, or urinary changes.
Referred Pain: Why Kidney Stone Pain Can Move to the Groin
Kidney stone pain can move from the side or back toward the lower abdomen, groin, or genital area. This is called referred pain, which means pain is felt in a location different from where the problem begins.
This referred pain happens because the kidney and ureter share nerve pathways with nearby areas of the abdomen, groin, and genital region. In clinical terms, pain from the upper urinary tract often follows nerve pathways around T11 to L2, so the location of the pain may change depending on whether the stone is higher or lower in the ureter.
For example, a stone higher in the ureter may cause more side or back pain, while a stone lower in the ureter may cause groin pain, bladder pressure, or urinary urgency.
Pain that changes location does not always mean the stone has passed. It may mean the stone is moving or irritating a different part of the urinary tract.
Changes in Urination
Frequent Urination: How Irritation Can Increase Urge
Kidney stones can irritate the urinary tract and make a person feel the need to urinate more often. Some people may feel a strong urge to urinate even when only a small amount of urine comes out.
This symptom can also happen with a urinary tract infection. Medical evaluation is important if frequent urination is new, painful, persistent, or occurs with fever, chills, blood in the urine, or back pain.
Burning, Pressure, or Straining With Urination
Some patients may feel burning, pressure, or discomfort when passing urine. Others may feel that the bladder is not emptying completely.
These symptoms may occur when a stone is near the bladder or passing through the lower urinary tract. They can also overlap with infection symptoms, so patients should not assume the cause without medical guidance.
Hematuria: What Blood in the Urine May Mean
Hematuria means blood in the urine.
Kidney stones can irritate the lining of the urinary tract and cause bleeding. Blood may be visible, which is called gross hematuria, or it may be microscopic and found only during urine testing.
Urine may look pink, red, tea-colored, or brown. Sometimes, blood is not visible and is only found on a urine test.
Both visible and microscopic blood can occur with kidney stones, but new blood in the urine should not be ignored. Infection, tumors, kidney disease, or other urinary tract conditions may also cause hematuria.
Any new blood in the urine should be discussed with a healthcare professional, especially if it occurs with pain, fever, chills, vomiting, or difficulty urinating.
Cloudy or Foul-Smelling Urine: Why Infection Must Be Considered
Cloudy or foul-smelling urine may happen with infection. When this occurs with fever, chills, pain, nausea, vomiting, or burning with urination, patients should seek medical care promptly.
A kidney stone and an infection can occur at the same time. Fever or chills with suspected kidney stone symptoms should be treated as urgent because infection behind a blockage can become serious quickly and may require emergency treatment.
Nausea and Vomiting
Nausea: How Kidney Stone Pain Can Trigger the Digestive System
Nausea can occur with kidney stones, especially during intense pain episodes.
This happens because the kidneys, ureters, and digestive system share connected nerve pathways. When a stone blocks urine flow and triggers severe visceral pain, the body may respond through the autonomic nervous system, causing nausea, sweating, weakness, or vomiting.
Nausea can also occur with infection, dehydration, medication side effects, or other abdominal conditions, so it should be evaluated in context.
Vomiting: When Symptoms May Become Urgent
Some people vomit during severe kidney stone pain. Persistent vomiting can make it harder to stay hydrated and may increase the risk of dehydration or worsening kidney stress.
Patients should seek urgent care if vomiting does not stop, if they cannot keep fluids down, or if vomiting occurs with severe pain, fever, chills, confusion, weakness, or reduced urination.
Kidney Stone Symptoms: What They May Mean and When to Seek Care
| Symptom | Possible Meaning | When to Seek Care |
|---|---|---|
| Severe flank pain | A stone may be moving, irritating the ureter, or blocking urine flow. | Seek urgent care if pain is severe, persistent, recurring, or worsening. |
| Fever or chills | This may suggest infection, especially if urine flow is blocked. | Seek urgent care immediately. |
| Blood in the urine | A stone may be irritating the urinary tract, but infection, kidney disease, tumors, or other causes are possible. | Contact a healthcare professional promptly, especially if blood is visible or occurs with pain or fever. |
| Persistent vomiting | Severe pain, dehydration, infection, or another urgent condition may be present. | Seek urgent care, especially if you cannot keep fluids down. |
| Trouble urinating or reduced urine output | There may be obstruction, dehydration, or kidney stress. | Seek urgent care, especially with pain, vomiting, swelling, or known kidney disease. |
When Kidney Stone Symptoms Need Urgent Care
Some symptoms may signal blockage, infection, acute kidney injury, or another condition that needs immediate attention.
Seek urgent medical care if you have:
- Severe pain in the side, back, abdomen, or groin
- Pain with fever or chills
- Nausea or vomiting that does not improve
- Blood in the urine
- Trouble urinating or inability to urinate
- Reduced urine output, especially with pain, vomiting, swelling, or known kidney disease
- Painful urination with fever or worsening symptoms
- Weakness, confusion, or feeling very ill
- Symptoms with a known history of kidney disease, kidney transplant, or recurrent stones
Patients who were already told they have a kidney stone should seek urgent care if fever, chills, worsening weakness, confusion, inability to keep fluids down, or reduced urine output develops later.
Patients should also seek care promptly if they have:
- One kidney or a single functioning kidney
- Chronic kidney disease, especially more advanced stages such as stage 3b to 5 or an eGFR below 45 mL/min/1.73 m²
- A kidney transplant
- Pregnancy
- A weakened immune system
- A history of urinary obstruction or complicated kidney stones
A kidney stone with infection or blocked urine flow can become serious. Timely care helps protect kidney function and overall health.
Medication Safety: Do Not Self-Treat Severe Stone Pain
Kidney stone pain can be intense, and some patients may try to manage it at home with over-the-counter pain relievers. However, patients should be cautious.
Nonsteroidal anti-inflammatory drugs, or NSAIDs, include medicines such as ibuprofen, naproxen, and similar anti-inflammatory pain relievers.
NSAIDs can help with renal colic in some patients, but they are not safe for everyone. The safest pain plan depends on kidney function, hydration status, other medical conditions, and current medications.
These medications may be risky for patients with chronic kidney disease, dehydration, reduced kidney function, a kidney transplant, heart failure, blood pressure problems, or certain medication combinations.
Using too much NSAID medication during a kidney stone episode may increase the risk of kidney injury, especially if urine flow is blocked or the patient is dehydrated.
Patients should not take leftover antibiotics, start new medications, increase doses, or combine pain medicines without guidance from a healthcare professional.
Fluids and Kidney Stones: Why “More Water” Is Not Always the Right Immediate Answer
Staying well hydrated can help reduce the risk of future kidney stones for many patients. In prevention plans, some patients may be advised to drink enough fluid to produce a high daily urine volume.
However, during an acute kidney stone attack, suddenly forcing large amounts of fluid does not necessarily “push the stone out.” If a stone is blocking urine flow, aggressive fluid intake may increase pressure behind the blockage and worsen pain.
The safest fluid plan depends on symptoms, kidney function, heart health, stone history, and whether there is nausea, vomiting, or obstruction. Patients should follow the instructions of their healthcare team.
How Florida Kidney Physicians Can Help
Your kidney care specialists may review symptoms, medical history, medications, urine testing, bloodwork, and imaging results to understand what is causing the problem.
Depending on the situation, evaluation may include urine testing to check for blood or infection, bloodwork to assess kidney function, and imaging to look for stones or blockage.
Imaging may include ultrasound or, when appropriate, a low-dose non-contrast CT scan. The best imaging choice depends on symptoms, kidney function, radiation considerations, pregnancy status, and the clinical situation.
Care may focus on:
- Confirming whether a kidney stone is present
- Checking for infection or obstruction
- Managing pain and nausea safely
- Monitoring kidney function
- Deciding whether the stone may pass on its own
- Referring for urgent or specialized treatment when needed
- Helping reduce the risk of future stones
For patients with recurrent stones, prevention may include reviewing stone type, urine chemistry, diet, fluid goals, medications, and risk factors. Recommendations should be personalized rather than based on one-size-fits-all advice.
For recurrent stones or higher-risk patients, prevention may include stone analysis, bloodwork, and sometimes 24-hour urine testing to better understand urine volume, calcium, oxalate, citrate, uric acid, sodium, and other risk factors.
Conclusion: Recognizing Symptoms Early Can Help Protect Kidney Health
Kidney stones can cause severe pain, urinary changes, nausea, vomiting, and blood in the urine. In some cases, symptoms may come in waves as the stone moves through the urinary tract.
Recognizing these symptoms early can help patients seek care before complications develop. This is especially important for patients with chronic kidney disease, one functioning kidney, kidney transplant, pregnancy, or signs of infection.
Florida Kidney Physicians can help evaluate symptoms, identify possible causes, and guide patients toward a safe treatment plan based on their kidney function, stone risk, and overall health.
Frequently asked questions
What does kidney stone pain feel like?
Kidney stone pain is often sharp, severe, and located in the side or back below the ribs. It may move toward the lower abdomen or groin as the stone travels through the urinary tract.
Why does kidney stone pain come in waves?
Kidney stone pain may come in waves because the ureter can spasm as it tries to move urine and the stone forward. This wave-like pain is often called renal colic.
Can kidney stones cause blood in the urine?
Yes. Kidney stones can irritate the urinary tract and cause blood in the urine. Blood may be visible or microscopic. New blood in the urine should be evaluated because infection, kidney disease, tumors, or other urinary tract conditions may also cause hematuria.
Can kidney stones cause nausea and vomiting?
Yes. Severe kidney stone pain can trigger nausea and vomiting through shared nerve pathways between the urinary tract and digestive system. Persistent vomiting should be evaluated promptly.
Can a kidney stone cause fever?
A kidney stone by itself does not usually cause fever. Fever or chills with kidney stone symptoms may suggest infection, especially if urine flow is blocked. This should be treated as urgent and evaluated promptly.
When should I seek urgent care for kidney stone symptoms?
Seek urgent care for severe pain, fever, chills, persistent vomiting, blood in the urine, trouble urinating, reduced urine output, or inability to urinate. These symptoms may signal obstruction, infection, acute kidney injury, or another serious condition.
Are NSAIDs safe for kidney stone pain?
NSAIDs such as ibuprofen or naproxen can help with renal colic in some patients, but they are not safe for everyone. The safest pain plan depends on kidney function, hydration status, other medical conditions, and current medications.
Should I drink a lot of water during a kidney stone attack?
Do not force large amounts of fluid during severe kidney stone pain without medical guidance. If a stone is blocking urine flow, aggressive fluid intake may worsen pressure and pain. Hydration advice should be personalized.
How do doctors diagnose kidney stones?
Doctors may use medical history, physical examination, urine testing, bloodwork, and imaging such as ultrasound or low-dose non-contrast CT when appropriate. The right tests depend on symptoms, kidney function, pregnancy status, and clinical risk factors.
Do all kidney stones cause symptoms?
No. Some small stones may stay in the kidney and cause no symptoms. Symptoms are more likely when a stone moves, irritates the urinary tract, or blocks urine flow.