Kidney stones: pain with a fever is an emergency, not a pain to sleep off

The most important point first: renal colic WITH A FEVER or shivering is an emergency, not a pain to sleep off. When a stone blocks the drainage of urine and the area above the blockage becomes infected, the situation deteriorates by the hour. Patients tend to do the opposite: increase their own painkillers and go to bed.

Recognising renal colic

The pain starts suddenly, usually on one side in the flank — below the ribs, towards the back — then travels down into the lower abdomen, the groin, and sometimes as far as the genitals. It surges in waves, easing then surging again. The most recognisable sign: no position makes it better; the patient is restless and cannot lie still.

• Nausea and vomiting alongside it are very common — this does not mean indigestion or food poisoning.
• Urine may be pink, red or brown like tea; sometimes only a test will reveal blood.
• Once the stone moves close to the bladder there is a frequent, burning urge to pass urine, with very little coming out each time.
• A stone sitting still inside the kidney may cause NO pain at all, and is found by chance on an ultrasound done for some other reason.
• How much it hurts says nothing about how large the stone is — do not use the level of pain to measure the level of danger.

If this is the first time you have had pain like this, do not diagnose a stone yourself; and if you already know you have stones, this episode of pain is still not certainly caused by them. What it is most often confused with:

• Musculoskeletal back pain: worse on pressing or on movement, does not travel down to the groin, and comes without vomiting.
• Testicular torsion in men: a swollen scrotum, severe pain, sudden onset — an emergency measured in hours, go now.
• A woman of childbearing age with severe lower abdominal pain: an ectopic pregnancy has to be ruled out first.
• An older person with sudden severe back or abdominal pain plus faintness and sweating: call for emergency help.

What to do now, at home

• Write down on paper the TIME the pain started, which side it is on and how far it travels — this is the first thing a doctor will ask.
• Take the temperature and note the time of each reading; take it again after every surge of pain and before going to bed. A fever changes the level of urgency completely, so do not estimate it by touch.
• Note the last time urine was passed, how much, what colour, and whether there was blood. Being unable to pass urine means going now.
• Drink as much as you can tolerate, if you are still able to drink and are not vomiting. But drinking a large amount all at once to “flush the stone out” is not a decision to make yourself: when the urinary tract is blocked, increasing fluid can make the pain worse — the amount of fluid is for a doctor to decide after examining you.
• Bring a list of the medicines you take, including blood-pressure tablets and diuretics.
• If a doctor has already asked you to collect your urine to catch the stone: pass urine through a clean strainer and keep the stone in a dry container to take to the appointment — the composition of the stone affects how recurrence is prevented. Only do this if you have been asked to.
• Do not drive yourself while you are in renal colic or have just taken a painkiller.

What NOT to do

• Do NOT increase your own painkillers and then wait overnight. This is the most common thing people do and the reason many reach hospital late: medicine masks the sensation of pain but it cannot open the blockage and it cannot clear the infection.
• Do NOT choose your own painkiller. Non-steroidal anti-inflammatory medicines such as ibuprofen, diclofenac or naproxen can affect the kidneys, most clearly in anyone who is dehydrated, has kidney disease, or is taking blood-pressure tablets or diuretics. Paracetamol (acetaminophen) is generally used, but which medicine and what dose is for a doctor or pharmacist to decide.
• Do NOT use antibiotics left over in the house or belonging to someone else. According to the US CDC, never take antibiotics prescribed for someone else and do not save antibiotics for later. If a kidney is blocked, antibiotics alone will not solve it either — the blockage has to be dealt with.
• Do NOT trust “stone-dissolving” or “stone-breaking” remedies sold online: the ingredients are unknown, and some contain painkillers or corticosteroids that mask the signs of deterioration.
• Do NOT use vigorous massage, coin-rubbing, wind-scraping or skin-pricking on a painful back.
• Do NOT skip the appointment just because the pain has stopped. The pain stopping does not mean the stone has passed; a kidney blocked silently can deteriorate over a few weeks with almost no pain.

When you must go to hospital

Families usually need a health professional for two things: to know whether this pain really is caused by a stone, and to know whether it has reached the point of needing hospital. A doctor or nurse can come to the house and examine, take blood and urine for testing, then say clearly whether imaging at a medical facility is needed or whether this can be monitored at home. But if any of the signs in the box above is already present — a fever above all — go to hospital first and call afterwards.

The signs of a kidney infection and the recommendation not to use someone else's antibiotics given in this article follow US CDC guidance; the article passes that on and does not replace being examined in person. Citing CDC here does not imply that CDC endorses Y Te Xanh or our services.

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