Chapter 2: The Warning Signs of Urinary Stones and Why the Pain Can Become Severe
Urinary stones can develop quietly, but when they move into a narrow part of the urinary tract, symptoms may appear suddenly. Some people describe the pain as one of the most intense experiences they have ever had. Others experience only mild discomfort, blood in the urine, or symptoms that resemble a urinary tract infection.
The wide variation in symptoms is one reason urinary stone disease can be difficult to recognize without medical evaluation.
Severe pain in the side or back
One of the most characteristic symptoms of a stone obstructing the ureter is sudden pain in the flank, the area between the lower ribs and the hip. The discomfort may begin on one side of the back and spread toward the abdomen, groin, or genital region.
The pain may rise and fall in waves rather than remaining constant. This happens partly because the ureter contracts as it attempts to move urine past the obstruction. Pressure can increase above the stone, and the surrounding tissues become irritated.
Unlike some types of muscular back pain, renal colic may make it difficult for a person to find a comfortable position. They may walk around, change positions repeatedly, or feel unable to sit still. However, pain patterns vary, and no single symptom confirms that a kidney stone is present.
A person with sudden, severe flank or abdominal pain should not assume that a stone is responsible. Other conditions, including appendicitis, abdominal emergencies, vascular problems, and certain reproductive or urinary conditions, can produce similar symptoms. Medical assessment is important to distinguish among them.
Blood in the urine
Blood in the urine, known as hematuria, is another possible sign of urinary stones. As a stone moves, its rough surface may irritate the lining of the urinary tract. This can cause small amounts of bleeding.
The urine may appear pink, red, or brown, but bleeding is not always visible to the naked eye. A laboratory urine test may detect red blood cells even when the urine looks normal.
Importantly, blood in the urine does not automatically mean that a person has kidney stones. Urinary infections, kidney diseases, injuries, and other conditions can also cause bleeding. In some circumstances, visible blood requires further investigation even if the discomfort disappears.
People should therefore avoid using the presence or absence of blood as a self-diagnostic test. A stone can exist without visible bleeding, and bleeding can occur for reasons unrelated to stones.
Nausea and vomiting
The kidneys and urinary tract have connections with the body's nervous system that can contribute to nausea during severe renal colic. Intense pain may trigger vomiting, sweating, restlessness, or a feeling of weakness.
Repeated vomiting creates an additional problem because it can prevent a person from drinking enough fluid. Dehydration may then worsen the overall situation, particularly if the person is already losing fluids or has reduced kidney function.
When vomiting is persistent, medical treatment may be necessary to control symptoms and maintain hydration. Some patients need medication administered in a clinical setting because oral medicines cannot be kept down.
Changes in urination
Urinary stones may cause frequent urination, an urgent need to urinate, discomfort during urination, or a sensation that the bladder has not emptied completely. These symptoms are particularly relevant when a stone reaches the lower part of the ureter or the bladder.
A person may also notice that urine flow becomes interrupted or that only small amounts of urine are produced. However, the significance of these symptoms depends on the location of the stone and the function of the remaining urinary tract.
An inability to urinate, particularly when accompanied by pain or a feeling of a full bladder, requires prompt medical assessment. Very low urine output can also indicate dehydration, obstruction, or impaired kidney function.
Fever and chills: Warning signs that should never be ignored
Fever and chills are especially important because they may indicate infection. A urinary stone can obstruct drainage and create conditions in which an infection becomes dangerous.
A patient with a suspected urinary stone who develops fever, shaking chills, confusion, severe weakness, or a rapid deterioration in their condition needs urgent medical care. An infected, obstructed urinary system can become life-threatening if not treated promptly.
In these circumstances, treatment may involve intravenous antibiotics and urgent drainage of the urinary tract. Removing the stone itself may need to wait until the infection is controlled, depending on the clinical situation.
It is dangerous to attempt to manage these symptoms at home using only painkillers or large amounts of water. An obstruction caused by a stone cannot always be resolved by drinking more fluid.
When a stone may pass without surgery
Many small ureteral stones can pass naturally. The likelihood depends on factors such as the stone's size, location, shape, and the patient's anatomy.
A clinician may recommend observation for a patient whose condition is stable, whose pain can be controlled, and who has no evidence of a dangerous obstruction or infection. The plan may include medication, hydration guidance, and follow-up imaging or appointments.
Some patients may be prescribed an alpha-blocker to help a ureteral stone pass, particularly in selected circumstances involving stones in the lower ureter. The usefulness of this approach varies with stone size and location, so it is not appropriate for everyone.
Pain management also needs to be individualized. Nonsteroidal anti-inflammatory drugs are commonly used for renal colic when appropriate, but they may not be suitable for people with certain kidney problems, gastrointestinal conditions, bleeding risks, or other contraindications. Other medication options may be considered by a clinician.
Patients should not force themselves to drink excessive quantities of water in an attempt to push an obstructing stone through the urinary tract. Maintaining appropriate hydration is important, but excessive fluid intake during acute obstruction can worsen discomfort without solving the underlying problem.
Why medical imaging matters
Doctors often use imaging to determine whether a stone is present, where it is located, how large it is, and whether it is blocking urine flow.
A noncontrast computed tomography scan is frequently used in adults when detailed assessment is needed. Ultrasound is another important option, especially in situations where radiation exposure should be minimized, such as during pregnancy. The choice depends on the clinical circumstances and local practice.
Urine testing may identify blood, signs of infection, or other abnormalities. Blood tests can assess kidney function and help identify complications. If infection is suspected, urine cultures and other tests may be required.
The results help determine whether observation is reasonable or whether intervention is necessary.
Why symptoms disappearing does not always mean the problem is solved
Pain may improve when a stone changes position or passes into the bladder. However, relief alone does not always establish that the entire stone has passed or that kidney drainage has returned to normal.
Depending on the circumstances, clinicians may recommend follow-up imaging or confirmation that the stone has been recovered. A stone may occasionally remain in the urinary tract even when symptoms improve.
If a stone is collected after passing naturally, laboratory analysis can help identify its composition. This information may guide dietary recommendations, medication, and future prevention.
The key message is that urinary stones can range from a manageable episode to a medical emergency. Sudden severe pain, visible blood in the urine, persistent vomiting, or difficulty urinating warrants medical assessment, while fever or chills in someone with a suspected obstructing stone require urgent attention.
Recognizing these signs can help people obtain the right treatment before a relatively localized problem develops into a more serious complication.
