Severe pain in the abdomen is the most telltale symptom of a kidney stone. These stones, called nephrolithiasis, are tiny pieces of minerals, such as calcium and salts, that collect in the kidneys and are too large to pass easily along the ureter to the bladder and out of the body. When they move from the kidney, stones cause severe waves of pain in the abdomen as well as other symptoms, such as problems urinating, nausea, vomiting, and fever.
The most common symptom of kidney stones is extreme pain anywhere in the abdomen that often comes in waves. It's an extremely severe pain often described as being comparable or even worse than childbirth. The pain usually means a stone is moving from the kidney through the ureter, the passage connecting the kidney to the bladder.
A kidney stone still in the kidney might not cause any pain or may cause pain on one side, near the lower back. If it has moved into the ureter, the pain might originate in the lower abdomen, side, or groin. Strong, continuous pain might indicate that the kidney stone is stuck and will not pass without medical treatment.
If a stone is in the ureter, the person may have difficulty urinating as the stone blocks urine from moving easily into the bladder. Stones can be smooth or have jagged edges, which can catch and tear at the walls of the ureter. This can cause the tissue to bleed, causing a burning feeling and urine that is tinted pink or red. As the stone moves toward the bladder, it can make the person feel like he or she needs to urinate more frequently.
Nausea and Vomiting
The severe pain that is one of the main symptoms of kidney stones can also cause nausea and vomiting in patients. This may, in part, be referred pain — pain that is felt in an area other than where it is being caused. In addition, there are nerves in the kidneys that connect to the stomach; when pressure in the kidneys is high, as it is when they cannot drain properly, these nerves signal the stomach to work more slowly, which can cause nausea. A patient might also lose his appetite or experience diarrhea or constipation.
Fever and Chills
Other symptoms of kidney stones include clammy, cold, hot, or sweaty skin accompanied by a fever or chills. A fever usually means that the stone has caused a blockage, and the kidneys cannot function normally. A blocked kidney can become infected, causing a potentially life threatening condition called sepsis. In some cases, kidney stones can also be caused by bladder infections, in which case a fever may be caused by that original illness.
Kidney Stones Without Symptoms
In some cases, people have kidney stones that do not cause any noticeable symptoms. If the stones are very small or stay in the kidney, they may not cause any problems or require any treatment. Often, such stones are only found when the patient is undergoing tests for an unrelated condition.
Anyone with severe pain or other symptoms of kidney stones should call a medical professional for an exam. Some symptoms are similar to a urinary tract infection or bladder inflammation, called cystitis, so it is important for a medical professional to rule out other causes. Kidney stones can be diagnosed with a blood or urine test, an ultrasound, or an X-ray with or without dye.
Most symptoms of kidney stones can be treated at home by the patient drinking lots of water and other fluids to flush out the stones and using over-the-counter medications such as ibuprofen or acetaminophen to help lessen the pain. About 10 to 20 percent of kidney stones are too big pass at home, though, and need further treatment. Shock waves can be used to break the stone into small enough pieces to pass naturally, or a stent may be inserted in the ureter to keep it open enough for the stone to pass. Minor surgery under general anesthetic may be needed to remove or break up the stone. If the stone was caused by or has caused an infection, that must be treated with antibiotics first, before the stone is removed.