Kidney stones are a common urological condition that affects millions of people worldwide.

These stones, which are hard deposits of minerals and salts, form within the kidneys and can cause significant pain and discomfort as they travel through the urinary tract.

The possibility of passing a kidney stone on its own depends on several factors, including the stone's size, location, and the individual's anatomy and health status.

For stones measuring 7mm, the likelihood of spontaneous passage is an important question that concerns many patients.

This blog by Mykare Health delves into the specifics of 7mm kidney stones, exploring their causes, symptoms, and potential to pass naturally, as well as the available treatment options.

Understanding Kidney Stones

Kidney stones form when certain substances, such as calcium, oxalate, or uric acid, become concentrated in the urine and crystallize. Over time, these crystals aggregate to form stones, which can range in size from tiny grains to larger masses.

Types of Kidney Stones

• Calcium Stones: The most common type, often composed of calcium oxalate or calcium phosphate.

• Uric Acid Stones: Formed when the urine is too acidic.

• Struvite Stones: Often associated with urinary tract infections.

• Cystine Stones: A rarer type, caused by a hereditary disorder.

Size Matters: The 7mm Kidney Stone

The size of a kidney stone is one of the most critical factors determining its ability to pass naturally. Stones are generally classified as:

• Small Stones (less than 4mm): These have a high likelihood of passing on their own.

• Medium Stones (4-6mm): These may pass naturally, though with some difficulty.

• Large Stones (greater than 6mm): These are less likely to pass spontaneously and often require medical intervention.

A 7mm kidney stone falls into the category of large stones, making its natural passage less probable.

However, certain factors can influence the outcome.

Factors Affecting Stone Passage

1. Stone Location

The stone’s position within the urinary tract plays a crucial role. Stones in the lower ureter are more likely to pass than those in the kidneys or upper ureter.

2. Urinary Tract Anatomy

The anatomy of the urinary tract varies between individuals, affecting the likelihood of stone passage. Narrower ureters or structural abnormalities can impede stone movement.

3. Hydration Levels

Adequate hydration can help flush out smaller stones, but its impact diminishes with larger stones like those measuring 7mm.

4. Gender

Studies suggest that males might have a slightly higher chance of passing larger stones due to anatomical differences.

5. Health Conditions

Conditions like obesity, diabetes, or a history of kidney stones can influence the stone's movement and passage.

Symptoms of a 7mm Kidney Stone

Kidney stones, including those measuring 7mm, can cause a range of symptoms:

• Severe Pain: Often described as sharp and cramping, the pain typically originates in the back or side and radiates to the lower abdomen or groin.

• Hematuria: Blood in the urine may appear pink, red, or brown.

• Frequent Urination: A persistent urge to urinate, often accompanied by discomfort.

• Nausea and Vomiting: These symptoms are common due to the pain or as a reaction to the stone’s presence.

• Fever and Chills: These may indicate an infection, a potential complication requiring immediate attention.

Can a 7mm Kidney Stone Pass on Its Own?

The likelihood of a 7mm kidney stone passing naturally is relatively low but not impossible. Studies indicate that stones larger than 6mm have only about a 20% chance of spontaneous passage. The timeframe for passage, if it occurs, can range from a few days to several weeks.

Certain measures can improve the chances of passing a stone

• Increased Fluid Intake: Drinking plenty of water can help flush the urinary tract.

• Medications: Alpha-blockers such as tamsulosin can relax the ureter muscles, facilitating stone movement.

• Physical Activity: Regular movement may help dislodge the stone.

However, these methods may not always be effective for larger stones like those measuring 7mm.

Medical Intervention for 7mm Kidney Stones

If a 7mm kidney stone does not pass on its own, medical intervention becomes necessary. Several treatment options are available, depending on the stone's characteristics and the patient’s overall health.

1. Extracorporeal Shock Wave Lithotripsy (ESWL)

This non-invasive procedure uses sound waves to break the stone into smaller fragments, which can then be passed naturally. ESWL is effective for stones located in the kidney or upper ureter.

2. Ureteroscopy

A minimally invasive procedure where a small scope is inserted into the urethra and bladder to remove or break the stone.

3. Percutaneous Nephrolithotomy (PCNL)

Used for larger or more complex stones, this surgical procedure involves creating a small incision in the back to remove the stone directly.

4. Medications

In some cases, medications can dissolve certain types of stones, such as uric acid stones.

Risks of Leaving a 7mm Kidney Stone Untreated

Ignoring a kidney stone, especially one of significant size, can lead to complications, such as

• Urinary Tract Infections: A blockage caused by the stone can increase the risk of infections.

• Hydronephrosis: Swelling of the kidney due to urine buildup.

• Chronic Kidney Disease: Prolonged obstruction or repeated infections can damage kidney function.

Preventing Kidney Stones

Once you’ve had a kidney stone, the risk of recurrence is high. Preventive measures include

1. Hydration

Drinking at least 2-3 liters of water daily can dilute urine and reduce the risk of stone formation.

2. Dietary Changes

• Limit foods high in oxalate, such as spinach and rhubarb.

• Reduce sodium intake to lower calcium levels in urine.

• Maintain a balanced diet with adequate calcium from dietary sources.

3. Medications

For individuals with recurrent stones, medications like potassium citrate or thiazide diuretics may be prescribed.

4. Regular Monitoring

Periodic imaging and urine tests can help detect stones early and prevent complications.