MEN VS. WOMEN: WHO’S AT HIGHER RISK OF KIDNEY STONES?

Kidneys play an important role in keeping your body healthy. They remove waste from the body through urine, help make red blood cells, and regulate your blood pressure. The kidneys are two bean-shaped organs about the size of a fist, located under the rib cage on each side of the spine.

For your body to function properly, it must balance the minerals within the body and keep many of the substances in the blood and other body fluids at the right level. When the kidneys are working properly, extra water and minerals such as sodium and potassium, leave your body in the urine.

Sometimes when they aren’t working properly, you can develop kidney stones. Both men and women can develop kidney stones, but men are more prone to developing them. According to the Kidney Foundation of Canada, about 12% of men and 6% of women will have a kidney stone at some point in their life.

In men, the first kidney stone is usually diagnosed between the ages of 40 and 60. For women, the age range is younger – between the ages of 25 to 30. Kidney stones also have a recurrence rate; it’s estimated that their likeliness to return is 15% in the first year and 50% in the following 10 years.

WHAT CAUSES KIDNEY STONES?

When urine has high levels of minerals and salts and low levels of liquid, it can crystalize to form a hard deposit known as a kidney stone (also called renal calculi, nephrolithiasis, or urolithiasis). Some kidney stones are the size of a grain of sand and may pass through the body in the urine without you knowing it. However, larger stones travelling from the kidney through the ureter to the bladder can cause severe pain.

Most kidney stones are caused by low urine volume and dietary factors, and are linked to family history. According to the Kidney Foundation of Canada, you are two and half times more likely to develop a kidney stone if one of your relatives has had one. This could be due to both genetic and environmental factors, such as having a similar diet or drinking patterns in families.

Low urine volumes from not drinking enough fluids or dehydration can cause your urine to be more concentrated. When it is more concentrated there is less fluid to keep salts dissolved.

HOW TO HELP PREVENT KIDNEY STONES?

Drinking more fluids will help to dilute the salts in your urine and reduce the risk of stones forming. Diet can also impact your chance of forming a kidney stone. Alberta Health Services has the following dietary recommendations to help avoid kidney stones:

• Limit salt and high sodium foods – try to keep sodium to less than 2300 mg per day.
• Limit intake of animal protein – meat, fish, poultry, and eggs should be kept to 2-3 servings per day.
• Limit vitamin C supplements – eat foods high in Vitamin C instead of taking supplements.
• Limit foods high in oxalate – you may be advised to avoid certain foods which are very high in oxalate, such almonds, French fries, spinach, etc.
• Limit high fructose drinks, such as fruit juices and sodas (especially dark-coloured sodas like Coca-Cola or Pepsi).
• Eat foods with calcium – calcium in food binds with oxalate so that less oxalate gets into your urine.
• Eat plenty of vegetables and fruit.

Other risk factors of kidney stones include excess body weight, certain supplements and medications, and some medical conditions.

WHAT ARE THE SYMPTOMS?

Small kidney stones frequently don’t cause damage and will pass through the urinary tract unnoticed. Larger stones can be quite painful. These hard mineral deposits start to hurt when they cause irritation or a blockage. This can make urinating difficult or increase pressure on the kidneys, often resulting in a sharp pain in the lower back.

Symptoms could be one or more of the following:

• A persistent need to urinate, urinating more often than usual or in smaller amounts.
• Cloudy or foul-smelling urine.
• Discomfort while urinating, such as pain or a burning sensation.
• Fever and chills if an infection is present.
• Nausea and vomiting.
• Pain that comes in waves and fluctuates in intensity.
• Pink, red, or brown urine.
• Severe pain in the lower back, lower belly, or along the sides.

HOW ARE KIDNEY STONES DIAGNOSED?

For kidney symptoms, such as pain, frequent urination, uncomfortable urination, etc., it’s important to speak with your health care practitioner. Your doctor will likely order a number of tests to investigate the cause for these symptoms. These tests often include blood or urine tests, and possibly medical imaging.

If needed, the following medical imaging exams could be ordered to investigate kidney stones:

• X-ray – kidney stones may show up on an X-ray.
• Ultrasound – an ultrasound can help identify the size and location of kidney stones, using high frequency sound waves to visualize and assess your kidneys and bladder. For both men and women, this exam can help detect fluid collection and obstructions like kidney stones.
• Computed tomography (CT) – a CT exam uses a combination of X-rays and computer technology to produce comprehensive images of the body. They are much more detailed than regular X-rays and can be used to evaluate if there is a presence of tiny stones.

For more information about these exams and how to prepare, please visit our services page.

REFERENCES

Alberta Health Services (2023) “Kidney Stones and Your Diet.” www.albertahealthservices.ca. Accessed August 31, 2023.

Kidney Foundation of Canada (2020) “Kidney Stones.” www.kidney.ca. Accessed August 31, 2023.

Mayo Clinic Staff (2022) “Kidney stones.” www.mayoclinic.org. Accessed August 31, 2023.

RADIMED (2023) “Kidney Stones: What Can I Do?” www.radimed.ca. Accessed August 31, 2023.

Urology Care Foundation (2023) “What are Kidney Stones?” www.urologyhealth.org. Accessed August 31, 2023.