Madhavi is caught by surprise at the intensity of the pain that she is feeling. She is doubled up and feels like somebody has punched her. The pain is cramping and she feels it travelling down from the left side of her back, along the side and into the lower abdomen. She feels waves of nausea as the pain makes her writhe.
Madhavi is feeling the effects of a kidney stone. Though more men have kidney stones (also known as renal calculi) than women, women can suffer from this most painful condition. Kidney stones are one of the most common disorders of the urinary tract.
What is a kidney stone?
A kidney stone is a solid mass made up of tiny crystals. It forms in the kidney and then can start travelling down the ureter, which is the tube that empties the urine from the kidney into the bladder. One or more stones can be in the kidney or ureter at the same time. The most common type of stone contains calcium in combination with either oxalate or phosphate. A less common type of stone is caused by repeated infection in the urinary tract. This type of stone is called a struvite stone and is more common in women.
Who gets kidney stones?
Stones occur more frequently in men. The prevalence of kidney stones rises significantly as men enter their 40s and continues to rise into their 70s. For women, the prevalence of kidney stones peaks in their 50s. Women who have a kidney stone are prone to getting more stones.
What causes kidney stones?
It is not quite clear why stones form. Some people have an inherited condition called hypercalciuria. In this condition, calcium is absorbed excessively from food and is excreted into the urine. This high level of calcium in the urine causes crystals of calcium oxalate or calcium phosphate to form in the kidneys. This condition may be the cause of renal stones in more than half of patients.
A person with a family history of kidney stones may be more likely to develop stones. In women, repeated urinary tract infections may result in stones in the urinary tract.
What are the symptoms of kidney stones?
Most commonly, renal stones manifest themselves in the hot summer months when people do not drink enough water and get dehydrated. Pain usually occurs when the stone is dislodged from the kidney and starts travelling down the ureter. The pain may be due to two reasons. First, the stone can block the ureter and the kidney gets distended with urine, leading to pain. The second reason is that if the stone is too large to pass easily, the muscles in the wall of the narrow ureter try to squeeze the stone into the bladder.
The diagnosis of kidney stones
Often, ‘silent' renal stones are found on an X-ray or ultrasound done during a routine health check-up. If a person is having severe pain, an ultrasound scan may be able to locate the stone.
Treatment
Since the pain is excruciating, most people suffering from it will require an injectable painkiller. The woman suffering from the pain of a kidney stone is asked to drink large quantities of water. If she cannot drink fluids because of severe nausea, then she is given intravenous fluids. Most women will be able to pass the stone just with this treatment. The woman is asked to pass urine through a fine tea filter so that the stone can be identified once it is passed.
Surgical treatment
Surgery may be needed to remove a kidney stone if it does not pass after a reasonable period of time and causes constant pain or is too large to pass on its own or is caught in the ureter blocking the flow of urine.
In recent times, surgery has been replaced by extracorporeal shock wave lithotripsy, which is the most frequently used procedure for the treatment of kidney stones. Ultrasound shock waves are directed at the stones. The stones break down into small particles and are easily passed in the urine.
It is very important to drink plenty of water, particularly in the summer months, to prevent kidney stones.
The author is an obstetrician and gynaecologist, practising in Chennai, and has written the book 'Passport to a Healthy Pregnancy'.
www.passport2health.in
