Dr. David Gu, director of HouFeng Diabetes & Hemodialysis Clinic, often receives patients who come in to relieve their renal pain. However, after examination, the vast majority of these patients have lower back pain caused by other factors such as muscle strain.
Kidneys are “silent organs,” he says, and many kidney diseases do not result in lower back pain, but may show other symptoms. The more common issue of kidney stones may indeed cause lower back pain though, he added.
It is often difficult to distinguish between lower back pain caused by kidney-related diseases and that caused by muscles and nerves in general. How can we differentiate them? And what are the warning signs of kidney disease other than back pain that we should look for?
3 Ways to Differentiate Between Lower Back Pain and Renal Pain
According to Dr. Gu, when a patient suffers from lower back pain, he diagnoses the cause by its location, nature, duration of an episode, and the triggering and/or relieving factors.
- The pain will not be relieved with the change of posture
When lower back pain occurs, does it get better with a change of posture? If so, the pain may be caused by a muscle injury or tissue damage. For instance, lower back pain caused by muscle strain is often due to improper posture and/or force. Sometimes the pain can be reduced by avoiding improper posture or adjusting the way you use force.
However, “lower back pain caused by kidney inflammation is persistent and even has sharp cramps that cannot be relieved by adjusting posture,” said Dr. Gu. The symptoms of low back pain vary from one cause to another, and a careful examination of the patient’s medical history is necessary to provide proper treatment.
- Severe pain when tapping on the lower back
The kidneys are located in the posterior lumbar region, and a lumbar tap is a common clinical examination method.
In case of back pain caused by kidney inflammation, tapping on the lumbar area will cause severe pain, as if the patient gets an electric shock, because of the vibration in the inflamed kidney area.
On the contrary, if the back pain or lumbago is caused by muscle strain, there will be no obvious pain when tapping on the lumbar area. However, localized pain can be felt when the affected area is pressed. By a simple physical examination, the source of pain can be distinguished first.
- The pain is acute and severe
Lower back pain can be classified as chronic or acute. Chronic pain, such as that caused by muscle strain, is usually recurring as it comes and goes, while low back pain caused by kidney inflammation is often acute and excruciating. Since it hurts so much, “patients usually go directly to the hospital for emergency care,” said Dr. Gu. Therefore, the majority of patients who can come to the outpatient clinic usually have lower back pain caused by muscle strain.
Acute Kidney-related Low Back Pain Has 3 Major Causes
The causes of acute kidney-related low back pain include stones, blood vessel obstruction, and bacterial infection. They can combine with one another to cause different symptoms.
People often visit his doctor’s office because they are worried that their back pain is caused by kidney problems. And among the kidney-related diseases that cause lower back pain, urinary tract stones are the most common. Depending on their locations, they may have different names, such as kidney stones, ureteral stones, and bladder stones.
When a stone causes a blockage in the urinary tract, it prevents urine from flowing downstream, and the kidneys continue to produce urine, causing the upstream area of the urinary tract to swell and causing cramps due to spasm of the smooth muscles of the ureter.
The pain caused by stone obstruction is often severe and unsettling, and it cannot be relieved by changes in posture. Patients with stones also experience tugging pain, and with the distribution of the nerves, it’s usually combined with pain in the groin area and inner thighs. And the pain can also be accompanied by nausea and vomiting.
Dr. Gu reminded us that though the pain can improve after taking painkillers, the obstruction might not improve and might cause the kidney function to deteriorate, so it is recommended to seek medical treatment as soon as possible if you have related symptoms.
Acute obstruction of blood vessels in the kidneys caused by blood clots can also lead to back pain and hematuria.
Aneurysms can also block blood vessels and are usually associated with high blood pressure.
In addition, malignant tumors may invade blood vessels or the urinary tract and cause obstruction as they grow larger. If a tumor bleeds, it may cause hematuria or blockage of the urinary tract and cause pain.
Patients mainly report a burning and painful sensation when urinating, along with fever. Patients with pyelitis caused by bacterial infection may also experience severe pain when they have a lumbar tap.
Dr. Gu explained that bacterial infections usually start with infections in the lower urinary tract, such as urethritis. If treatment is delayed, the infection may extend upward to the bladder and even the renal pelvis, at which point lower back pain may occur. As the disease progresses, the location of the pain will vary and the fever will become more severe.
4 Signs of Kidney Injury
The kidneys are important organs in the human body, so back pain does make people feel uneasy: “Is there something wrong with my kidneys?” In fact, the kidneys are “silent organs,” and it is difficult to detect symptoms unless the disease is so severe that it becomes a chronic renal disease. On the contrary, most of the kidney-related diseases that cause acute pain can be cured with treatment.Therefore, in addition to back pain, there are four symptoms of chronic kidney diseases that you should pay attention to and seek medical attention if they occur:
- The appearance of bubble urine or hematuria
- Sudden decrease in urine volume
- Combination of the above, with high blood pressure
- Fatigue
According to Dr. Gu, these symptoms are mainly due to kidney damage to a certain extent, resulting in the organ’s inability to excrete waste products from the body.
He reminded us that most of the common kidney problems are caused by long-term chronic diseases (hypertension, diabetes, hyperlipidemia, and obesity). Therefore, to take good care of the kidneys, it is best to start at the source, such as controlling the blood pressure, blood sugar, and blood cholesterol levels.
