How to Differentiate Between Back Pain and Kidney Pain?

Kidney Pain

The kidneys are a pair of bean-shaped organs on either side of the spine, located below the diaphragm, and behind the liver and stomach. The kidneys are responsible for filtering waste from blood plasma, thus keeping the body free from the toxic effects of fluid waste build up. They are also essential to maintain the levels of salt, pH and water in blood.

Due to their role in the removal of waste from the body, the kidneys can become susceptible to damage or infection. For example, when you do not drink enough water, calcium, oxalate, cystine or phosphate will start to accumulate, these minerals could crystallise and form stones, which usually presents as a severe sharp, stinging pain in the back. A deep, dull ache in the front, back or sides of the belly is a common presentation of kidney infection.

Back Pain Causes

Meanwhile, bones, muscles and nerves make up the human back. Pain in the back can manifest in any part (cervical, thoracic, lumbar, sacral, pelvic) depending on where injury or damage has occurred. The kidneys rest against the back muscles, extending from the T12 to L3 vertebral levels, with the right kidney usually located slightly lower than the left due to presence of the liver. Therefore, it can be difficult to tell if the pain is originating from the lower back or the kidneys, or both. Due to the anatomical position of the kidneys and resemblance in presenting symptoms, kidney-related pain must be ruled out in patients with back pain, especially in the lower back. Nevertheless, back pain is extremely common hence, it is more likely that someone has back pain rather than kidney pain.

The causes of back pain are numerous. They can include mechanical causes such as muscle strains, ligamentous sprains, joint dysfunctions and disc herniations. These are usually due to overuse, poor posture or improper lifting techniques. For instance, a strained muscle can feel sharp and is worsened with movement. Nerve root pain in the lumbar spine can present as numbness and tingling sensations in the lower back that radiates into the lower limb. Pathological causes of back pain such as cancer, fracture and infection too can present as persisting pain that gets worse over time.

How Do We Compare back pain and kidney pain?

The main difference between lower back pain and kidney pain is that kidney pain tends to be experienced higher in the back (T12-L3 vertebral levels) compared to lower back pain (L1-L5 vertebral levels). Furthermore, kidney pain is usually persistent until it is resolved, while lower back pain can be relieved with conservative care.

The table below may act as a quick-reference guide for you to determine if you are more likely to have back pain or kidney pain:

	Back Pain	Kidney Pain
Area Affected	Any part of the back, but the lumbar spine is most commonly affected. Usually felt over the spine or in the soft tissue surrounding the spine.	Usually felt below the rib cage, in the flanks on either side of the back. Pain can be felt on just one side or both sides of the back, but it feels deeper.
Quality of Pain	Differs depending on which structure of the back is causing pain: – Bone pain caused by cancer can feel tender and achy deep in the affected bone. – Muscular pain can feel dull, sore and achy and can become worse if used. – Nerve pain can feel like an electrical, sharp-shooting, burning or stabbing sensation that goes down to either one or both lower limbs.	Usually feels like a constant, dull ache in the back, or a severe sharp pain that comes in waves. The pain of larger kidney stones passing through the ureter can mimic musculoskeletal pain.
Radiation of Pain	Can radiate into the upper and lower limbs depending on which intervertebral disc level is involved.	Can spread from the flanks at the sides to the abdomen, groin and inner thigh. Presence of kidney stones can manifest as colicky abdominal pain radiating from the loin to the groin.
Associated Symptoms	Trigger points from tight and fatigued muscles may also refer pain to other parts of the body, with each muscle having its own referral pattern.	Rigors and fever Painful urination (dysuria) Blood in urine (haematuria) Dark-coloured or frothy urine Constipation Diarrhoea Urinary retention Nausea and vomiting
Relieving Factors	Usually responds well to conservative care, such as rest, ice, heat, exercise etc.	Conservative care will not relieve kidney pain. The source of the pain must be identified and be treated for to ease the pain.

Assessment and Management

Given that kidney pain can sometimes be confused with back pain, it is not uncommon for chiropractors to see patients having either types of pain, or both. A detailed history would be taken and a physical examination with suitable tests would be done to determine the nature of the pain. Should there be any further need for investigation, the chiropractor can also order a complete blood count (CBC) and urinalysis to assess the function of your organs. If any problems are detected with kidney function on the laboratory result, then a prompt referral to a specialist is warranted.