While there are telltale signs of kidney stones including sharp pain in the side and back, frequent urination, blood in the urine, and vomiting/nausea, these symptoms may also be present in many other medical conditions. Because the timing and severity of the symptoms depend on the size of the stones, there is no textbook case for kidney stones. The pain, which is typically located along the sides of the back, may also be referred to the groin and abdomen. Many people pass smaller kidney stones without ever realizing these stones are present. Other people experience severe pain and worrisome urinary signs that rightfully send them to the hospital.
It’s also true that some conditions are able to specifically mimic the pain of left or right kidney stones. Appendicitis, for example, presents with pain in the lower right abdomen, while diverticular disease is more common when the pain is experienced on the right side of the abdomen. Meanwhile, gastroenteritis is often associated with more diffuse pain that can mimic stones in both kidneys.
Non-contrast computerized tomography (NCCT)
One of the most powerful tools at the physician’s disposal and is commonly ordered as part of the differential diagnosis for kidney stones, a non-contrast computerized tomography (NCCT) is the technical term for a CT scan that doesn’t use contrast material. The CT scan doesn’t need the assistance of this contrast material to image most parts of the abdomen, including the kidney stones. As such, in cases where kidney stones are not present, other diseases can be effectively diagnosed through the same diagnostic imaging. It could be a dilated appendix. It could be a collapsed bowel. It could be an inflamed pancreas. It could be a blocked colon. Here are three of the most common examples:
Acute pancreatitis: Pain in upper left abdomen may be kidney stones, but it’s just as often a case of acute pancreatitis. When the pain of acute pancreatitis is higher in the abdomen, it may present with symptoms similar to cardiac arrest. When the pain is lower and more to the side, it may be confused with kidney stones. Other symptoms of pancreatitis and kidney stones overlap as well, most notably discomfort when urinating.
Gastroenteritis: The major symptoms of gastroenteritis are abdominal pain, nausea/vomiting, watery diarrhea, general aches and pains, and mild fever. This condition affects the GI tract. As part of the urinary system, kidneys and kidney stones can mimic UTIs and other conditions that affect the urinary system. However, because the kidneys share many nerve connections with the GI tract, there is considerable overlap of symptoms, especially when it comes to nausea and vomiting. The absence of any troublesome signs on the NCCT imaging may help point to a diagnosis of gastroenteritis. Gastroenteritis may not be evident with NCCT but can be confirmed through analysis of stool samples.
Acute appendicitis: This is another condition that includes abdominal pain with nausea and vomiting. Pain that starts higher in the abdomen may move lower and off to the right side, mimicking the symptoms of a right kidney stone. The onset of symptoms occur quickly, but in a worst-case scenario, may subside after a time if the appendix bursts. Kidney stones are often passed harmlessly at home, but the symptoms with kidney stones also come on quickly and may not be easy to diagnose on your own. Acute appendicitis is a good example of why you shouldn’t avoid the hospital if you’re at all uncertain about the nature of your illness.
Other Conditions with Symptoms Similar to Kidney Stones
These are only a few of the conditions with symptoms similar to kidney stones. There are multiple online guides out there that provide insights into a differential diagnosis for kidney stones, and we’re committed to providing the best information possible. We’ve put together our own explanation and list of medical conditions, but we encourage you to learn more through emDocs and Epocrates.