Kidney stones one of the most common kidney problems, and a frequent cause of urinary tract infections. There are several types of kidney stones, but the most common are formed with two main components: calcium and oxalate. In some cases, kidney stones may have a strong genetic component, but the diet and our daily liquid intake are very important factors contributing to the sedimentation and consolidation of kidney stones.
An individual may suffer from kidney stones without displaying any specific symptom. They usually appear after kidney stones move their way through the urinary tract, which is often accompanied by additional symptoms when it gets infected.
The most common signs and symptoms of kidney stones are as follows:
1- Pain symptoms
The most common symptom of kidney stones is pain. As mentioned earlier, they remain asymptomatic in many cases, and pain only ensues when kidney stones move and start going down in the urinary tract. The pain that comes from kidney stones is not always in the same area. Some patients describe pain in their lower back, in their flanks or groin. However, it is very common to have radiation to another area of the body, usually a lower area corresponding to the primary source of pain.
The pain from kidney stones results from an injury to the urinary tract. However, it is important to note that this tissue does not receive sensory impulses the same way our skin does. Instead of specific nerve terminals, the urinary tract receives a group of nerve terminals coming from the same neuron. Thus, whenever there’s an injury to a determined area of the urinary tract, we may not be able to locate the injured area precisely. Instead, the patient reports a dull and poorly localized pain that often moves or irradiates to another area.
The most common type of pain is back pain that radiates down to the groin area. Sometimes, male patients describe an intense pain in their testicles, and female patients may feel pain in their labia majora. This is because pain follows the same trajectory as the nerve that innervates all of this area.
2- Leg Pain
As a part of the pain symptoms, patients often describe pain in the corresponding leg to their back pain. Sometimes, leg pain feels like a reflection or radiation from back or groin pain, but in many other cases, it appears to be a separate symptom.
Leg pain caused by kidney stones is also explained by the same reasons stated above. This type of pain is often dull and poorly located because it comes from a single neuron following a very long trajectory. When there’s an injury at any level of this trajectory, the pain symptoms are triggered, and the brain interprets pain in the whole trajectory of the nerve. However, in many cases, pain located in the groin, testicles or legs may indicate that the kidney stones are lower in the urinary tract.
In many cases, leg pain can be severe enough to cause mobility issues. Patients become unable to walk properly, and do so without supporting themselves on the affected leg. In other cases, there’s no leg pain at all or a very mild discomfort that’s poorly localized.
3- Painful urination
Pain symptoms may become even worse during urination, but this type of pain is different, often described as a burning sensation, and similar to that we feel during urinary tract infections. This pain is located in the urethra and limited to the time patients urinate.
Painful urination might be caused by a kidney stone going down into the urethra, but may also be triggered by a urinary tract infection, which is a common problem in kidney stones. This symptom is called dysuria, and it is often felt as sharp pain or burning sensation going through your urethra. Different to the pain you may feel in your back and going down to your groin, this burning during urination is very localised in a specific location because this area has more specialised sensitivity compared to the higher urinary tract.
Patients are often misled when they only feel pain or burning when urinating. They may think they have a urinary tract infection instead of kidney stones. However, in many cases, both health problems may coexist in the same patient.
4- Fever and chills
Fever and chills are also common symptoms associated with kidney stones. They usually appear when there’s a coexisting infection of the urinary tract, but sometimes they start alongside with the pain symptoms, and patients enter to the emergency room with a sudden onset of pain, fever, and chills.
Fever is a common symptom of infectious and inflammatory diseases. The organism increases body temperature to help the immune system combat diseases or foreign bodies. This is achieved after regulating the body’s thermostat, which is located in the hypothalamus, a special region of the brain that controls vital body functions such as hormonal balance, hunger, and thirst.
Since our body thermostat is adjusted at a higher level than normal, the rest of the body starts perceiving that temperature is lower. Thus, we start feeling chills and sensation of coldness, the muscles start contracting to create additional heat, and we might even get shivers and similar symptoms. All of them are caused by a change in our central nervous system.
Fever in kidney stones is a continuous type of fever. It might start along with pain symptoms and be sustained after the rest of the symptoms disappear. In the event of fever, it is important to take into consideration urinary tract infections as a differential diagnose.
5- Nausea and vomiting
In many cases, kidney stone pain is severe enough to cause nausea and vomiting as well. Gastrointestinal symptoms are frequent during acute pain caused by kidney stones. Nausea and vomiting are often accompanied by anorexia and loss of appetite.
Pain puts your whole body in stress, and severe pain causes very intense stress that triggers nausea and vomiting. Pain from the abdominal organs travels via afferent neurons to reach the central nervous system. The pain signals are processed in the brain and integrated into a special system in the brain called emetic centre. From this area, the efferent emetic signals go down through the central nervous system and start causing the sensation of nausea and vomiting. There are two different centres that trigger vomiting: one located in the medulla of the brain that’s activated first, and the second one is called integrative vomiting centre, and it is the one that controls vomiting as a reflex.
Sometimes, nausea is not severe enough to cause vomiting in the event of kidney stones. When emesis starts, it is often not severe enough to cause electrolyte problems. However, special care should be given to the elderly and infants because they often experience electrolyte imbalances more easily than young adults, and such additional health problem might become life-threatening.
6- Urgency to urinate a small amount
Patients with kidney stones often report urgency to urinate, and if they already suffer from incontinence, their symptoms may worsen even more if they have an overlying infection of the urinary tract. The urgency to urinate is often described as a sudden and unexpected urge to go, and sometimes patients may even experience a leak, even if they do not suffer from incontinence.
However, during urination, most patients report they are only able to urinate a very small amount. This is even more prominent in patients with known prostate enlargement. In some cases, patients report difficulty passing urine, and this is common when the kidney stones are halfway out, blocking the way. In these cases, it is very important to search for immediate medical attention.
7- Increased urination
Patients with kidney stones often describe they need to go to the bathroom too much. If they have a coexisting infection, they may also complain about an urge to urinate constantly waking them up in the middle of the night. The formation of urine might be increased, but this reported symptom is often confused with urinating frequently and in small amounts. In every case, both increased urination and urgency to urinate are more common as the kidney stone is passing down the ureter. Therefore, it is considered to be a temporary symptom, and it is not sustained over time.
Sometimes, patients describe an excessive volume of urine and frequent urination. In these cases, it is important to find out whether or not there’s a change in the normal function of the kidney or any other disease or drug that’s contributing to this. However, in most cases increased urination is just another symptom of kidney stones.
8- Blood in the urine
Blood in the urine is commonly called hematuria by physicians. It is considered to be both a sign and a symptom. It is a symptom when reported by the patient and not visible by the doctor or lab report. When it is measured by any observational means, hematuria becomes a very important symptom to diagnose kidney stones.
Sometimes, having hematuria along with back pain and a burning sensation to urinate is the only thing a clinician needs to diagnose kidney stones. However, there are several differential diagnoses to rule out, and you should not raise any conclusion without consulting a healthcare professional.
Hematuria might be divided into several grades depending on how much blood is seen in the urine. It is often a minimal amount that changes the colouration of urine to a reddish colour. Excessive hematuria should be studied carefully because it may signal a more serious issue.
9- Cloudy urine
Instead of blood in the urine, patients may describe cloudy urine, which is common whenever kidney stones cause an infection to the kidneys or any other part of the urinary tract. Urinary tract infections resulting from kidney stones usually affect the kidneys or the bladder, but might also affect the ureters and urethra.
In some cases, cloudy urine is caused by sexually transmitted diseases instead of kidney stones, which is the reason why we should not take it for granted and may need the opinion from a professional.
Cloudy urine is often called pyuria, and it results from a high concentration of white blood cells in the urine. These white cells migrate to the urinary tract when there’s a bacterial growth, mixes with urine as it is expelled out of the body, and may give the appearance of milky or whitish urine. Similar to hematuria, there are different grades of pyuria depending on the severity of the underlying infection.
10- Foul-smelling urine
Patients with kidney stones often report a change in the colouration of their urine that is accompanied by a change in the smell. Foul-smelling urine is a sign of urinary tract infection, which is the most common complication of kidney stones. The reason why urine changes colours is because the bacteria growing in the urinary tract starts feeding off the urea. However, it is important to distinguish this from other causes of foul-smelling urine, such as abnormal communications between the digestive system and the urinary tract.
As you can see, kidney stones might be asymptomatic, cause an acute pain that’s often described as unbearable and excruciating, and may leave patients with a urinary tract infection for a longer time. Depending on the type and how large kidney stones are, they might need oral treatment or surgery as a treatment approach. However, the appropriate tests and physical exam to determine what’s best for you should be ordered, performed, and interpreted by a physician.
Be sure to seek medical attention right away if you experience burning pain with nausea and vomiting, blood in your urine, difficulty passing urine, and severe pain in your back, groin and leg. Remember kidney stones usually come together with urinary tract infections, and do not take it lightly if your kidney stone symptoms appear to go away.