Symptoms of Kidney Stones

Kidney stones are a common urological condition, and their symptoms vary depending on the size, location, and movement of the stones. Some patients may have no obvious symptoms in the early stages, but as the stones grow larger or cause obstruction of the urinary tract, severe pain and other serious symptoms can occur. Early detection of symptoms and prompt medical consultation can effectively prevent complications.

The symptoms of kidney stones are not limited to the urinary system and may also be accompanied by gastrointestinal or systemic discomfort. Different patients have varying sensitivities to pain and severity of symptoms, so understanding the characteristic symptoms at each stage is crucial. This article will detail the full spectrum of symptoms from early signs to severe complications and provide guidelines for medical consultation.

Early Symptoms and Signs

Early symptoms of kidney stones are often mistaken for general muscle soreness or mild discomfort, leading to delayed diagnosis. Typical early signs include:
1. Mild, unilateral flank or lateral abdominal pain after moderate activity
2. Urine slightly darkened or tinged with blood
3. Brief burning sensation during urination

Some patients may experience nonspecific symptoms such as:

• Lower back soreness upon waking in the morning
• Slight increase in urination frequency but decreased volume per void
• Mild tenderness in the lower back area

If these signs persist for more than 48 hours or are accompanied by a slight fever (around 37.5°C), it is recommended to undergo urinary system ultrasound to detect small stones less than 0.5 cm early.

Common Symptoms

Severe Pain

When the stone moves to a narrow part of the ureter, it triggers renal colic, characterized by:
- Paroxysmal, knife-like pain in the affected flank
- Pain radiating along the ureter to the lower abdomen or groin
- Pain severity can reach 10/10, significantly affecting daily activities

Urinary Abnormalities

Obstruction of the urinary tract by stones can cause:

• Terminal hematuria (pinkish urine at the end of urination)
• Frequent urination with inability to pass a sufficient amount of urine

50% of patients will have visible hematuria, while 20% may only have microscopic hematuria requiring professional testing for detection.

Progression of Disease and Symptom Changes

Complete obstruction of the urinary tract by stones can lead to the following advanced symptoms:

• Complete urinary obstruction: inability to urinate, resulting in lower abdominal distension
• Infection complications: fever (over 38.5°C), chills, and flank swelling
• Renal impairment: persistent obstruction over 48 hours may cause systemic fatigue and loss of appetite

After moving to the bladder, the pain may shift to the pubic area, accompanied by frequent urination and urgency. Some patients may experience a burning sensation during urination, indicating irritation of the urethral mucosa by the stone.

Temporal Characteristics of Symptoms

The nature of pain varies with the movement of the stone:
- Stones within the kidney: intermittent dull pain
- Obstruction of the upper ureter: persistent severe flank pain
- Obstruction of the lower ureter: cramping pain in the lower abdomen or groin
- Near the bladder: suprapubic tenderness

When to Seek Medical Attention

The following situations require immediate medical attention:
• Severe pain that prevents standing or walking
• Difficulty urinating with complete anuria
• Fever over 38.5°C lasting more than 4 hours

Warning signs for medical consultation include:
– Long-term unexplained lower back soreness with microscopic hematuria
– Unexplained unilateral flank tenderness
– History of kidney stones with recurrence of similar symptoms

If signs of complications appear, consider it an emergency:
▷ Shortness of breath with cold sweat
▷ Persistent vomiting over 2 hours
▷ Urine that appears like meat slurry with altered consciousness

 

Frequently Asked Questions

Why does kidney stone pain radiate and prevent lying flat?

Movement of kidney stones irritates the kidney or ureter, causing severe colicky pain. Patients often find it unbearable and cannot maintain a fixed position, even moving constantly to relieve discomfort. This pain may be accompanied by hematuria or nausea, and immediate medical evaluation is recommended to assess the need for pain relief or lithotripsy.

What dietary habits increase the risk of kidney stones?

High oxalate foods (such as spinach, chocolate), excessive protein or salt intake can promote crystal formation. Insufficient water or fiber intake may also increase risk. It is recommended to drink 2-3 liters of water daily and consult a nutritionist to adjust dietary structure.

What should be注意 after extracorporeal shock wave lithotripsy (ESWL)?

Post-procedure, small stone fragments may be expelled, which can cause hematuria or pain during urination—these are normal reactions. Drink plenty of water to promote expulsion and avoid strenuous activity. If pain persists or fever develops, return to the hospital for further assessment and treatment.

Do asymptomatic kidney stones require treatment?

If the stone is less than 5 cm and not obstructing the urinary tract, doctors may recommend observation. Regular imaging follow-up is necessary to monitor size changes. If signs of infection (fever, flank pain) or renal dysfunction occur, active treatment is required.

How to differentiate kidney stone pain from gastrointestinal issues?

Kidney stone-induced flank or lower abdominal colic is usually sudden and severe, often radiating to the inner thigh, and commonly accompanied by hematuria. Gastrointestinal problems like gastric colic are often related to eating times, with pain located in the upper abdomen. If symptoms are unclear, ultrasound or urine tests should be performed for confirmation.