Kidney stones: symptoms, types and treatments
Kidney stones. They’re small, but they’re mighty. Did you know that more than half a million people head to the emergency room for kidney stones each year?1 You may be wondering how something so little can be so painful. Most kidney stones range in size from a grain of sand to a chickpea. But rarely some can grow to be the size of a golf ball. Read on to learn what kidney stones are and what to know if you think you may have one.
What are kidney stones?
A kidney stone is a hard mass made up of minerals, salts and chemicals that form inside your kidneys. Specifically, these substances can be calcium, uric acid, xanthine. They’re all waste products that typically leave your body through urine. But if there’s not enough urine to help carry these waste products out of your body, they can concentrate and crystalize into a tiny little stone.2,3
What are the types of kidney stones?
Depending on what it’s made of, kidney stones are classified into groups. This helps doctors determine why you got it in the first place and how you might be able to prevent future stones. So, if you pass a stone at home, save it for a doctor’s analysis. The different types of kidney stones are:2,3
- Calcium stone: This is the most common type of kidney stone. Calcium stones usually develop as calcium oxalate and they form when calcium and oxalate combine in your urine. Calcium oxalate stones are mainly linked to high levels of oxalate, low amounts of calcium and poor fluid intake. A second variation of calcium stones develop as calcium phosphate. These stones are often caused by metabolic conditions or certain medicines.
- Uric acid stone: Uric acid stones form when you lose too much fluid (think dehydration). That could be from chronic diarrhea, malabsorption or simply not drinking enough water. It’s also common in people with a high-protein diet, metabolic conditions, diabetes or certain genetic factors.
- Struvite stone: These stones are less common and form when there’s a urinary tract infection. They can grow quickly and may show little or no symptoms.
- Cystine stone: This type of stone is rare and forms in people who have a hereditary condition called cystinuria. It causes your kidneys to release too much of a specific amino acid (cystine).
How are kidney stones diagnosed?
If your doctor thinks you might have a kidney stone based on your symptoms and physical exam, they’ll likely do tests to determine diagnosis.
- Blood test: A blood test can tell your doctor if there’s too much calcium or uric acid in your blood, which may indicate the likelihood of a stone. Markers in your blood show your doctor how healthy your kidneys are and can help identify other medical conditions that might be related (or not) to your kidney stone.
- Urine test: This 24-hour collection test could help show if you’re passing a lot of stone-forming minerals and/or not enough stone-preventing substances.
- Imaging: Things like CT scans and ultrasounds can help spot kidney stones (even really small ones).
If you think you might be passing a stone, you’ll likely be asked to urinate through a strainer so you can catch it — even though it might feel a little odd to go to the bathroom with a strainer in hand. But it’s important for your doctor to check what your stone is made of so you can try to prevent future kidney stones.
What are the signs and symptoms of kidney stones?
If you’ve been lucky enough to have never experienced a kidney stone, you might remember less fortunate friends or family members say it was the worst pain of their lives. You may get pain in your abdomen, lower back and groin as the stone makes its way through your narrow ureter and eventually out of your body. A kidney stone may not cause symptoms unless it moves from your kidney and gets lodged in your ureter. There, it could block the flow of urine and cause your kidney to swell and spasm.3
Symptoms of kidney stones include:2,3
- Dull or sharp pain in your side, back, belly, groin or below your ribs
- Trouble, pain or burning while you urinate
- Feeling the need to urinate often or in small amounts
- Bloody urine
- Foul smelling or cloudy urine
- Pink, red or brown urine
- Nausea and vomiting
Keep in mind, kidney stone pain can move around as the stone moves. So, it’s common for the pain to travel around your mid-section and even change in intensity.