The Truth About Kidney Pain
Though the kidneys are located at the back, just below the rib cage, fortunately, all back pain is not necessarily kidney pain!
A strong sense of deja vu washes over me, as I hear a young man seated in my office uncomfortably say, ‘doctor, my back hurts a lot – do you think I need to get my kidneys checked?’ I hear this question at least once every day! Statistically, the world over, eight in ten persons have had back pain at some time or the other in their lives.
Many a time, back pain can be severe and debilitating and can totally destroy the quality of life. But like all things medical, early diagnosis and appropriate treatment is the key to management of any disease and back pain is no exception.
Though the kidneys are located at the back, just below the rib cage, fortunately, all back pain is not necessarily kidney pain. Other structures in the back, apart from kidneys, include the spine, the muscles on either side of the spine, the nerves supplying the lower part of the body, the adrenal glands and the pancreas. Injury or dysfunction of any of these can cause back pain. Sometimes, bladder, uterine or ovarian disorders can also manifest as back pain.
The kidneys are very rarely painful and most kidney diseases are silent, painless killers! The few instances where kidney disease can be painful are: kidney stone disease, kidney infections, kidney injury and bleeding, kidney cancer and kidney cysts.
Kidney Stone Disease
This is by far the commonest cause of kidney pain. Kidney stones are formed due to a genetic tendency compounded by some external trigger. This trigger is often dietary due to excessive consumption of red meat, alcohol, salt, calcium, vitamin D and spinach, to name a few, Often, drinking lesser fluids or losing body water due to diarrhoea or perspiration forms a trigger to stone formation.
Certain infections can also predispose stone formation. Rarely, parathyroid gland disorders cause high calcium levels and stone formation. However, stones within the kidney are usually painless, unless they are very large. Kidney stones cause maximal pain when they are moving down the urinary passage (inside the tube connecting the kidney to the bladder called the ureter).
This pain is called ‘ureteric colic’ and is rated as one of the five most painful conditions after heart attack, fractures, childbirth and cluster headaches. It is diagnosed by ultrasound or CT scan of the kidneys. It is initially treated with medicines and later by surgery, if medicines do not work.
Infections of the kidney include Pyelonephritis (bacterial, viral, fungal and tubercular infections of the kidney tissue) and Kidney Abscesses (pus collections within the kidneys). Here, the patient develops pain and tenderness in the side of the trunk and the back, beside the vertebral (spinal) column. It is diagnosed by blood cultures, urine cultures, ultrasound or CT scan and treated by antibiotics and/or surgery.
Kidney Injury And Bleeding
At times, trauma to the kidney in the form of accidents, physical attacks and surgery can occur. This will lead to bleeding from the kidney as the kidney is a collection of blood vessels, which deals with 180 litres (yes litres!) of blood every day. Bleeding causes the kidney covering or capsule and kidney tissue to stretch beyond limits leading to pain. Bleeding is diagnosed by ultrasound and CT scan. It is treated by blood transfusions, bed rest, antibiotics and in extreme cases, by surgery.
Kidney cancers cause the capsule of the kidney to stretch causing kidney pain. Some cancers spread to surrounding tissues and bones and nerves causing pain. People with kidney cancers have back or flank pain, fever, weight loss and blood in the urine. Kidney cancers are diagnosed by urine tests, ultrasound and CT scans. They are treated by surgery and/or chemotherapy.
Certain genetic diseases cause multiple cysts in the kidneys, an example being Polycystic Kidney Disease which can affect 50 per cent of the children if one parent has it. Age related cysts can appear in individuals above the age of sixty (which is also called – tongue-in-cheek, the age of ‘cysty!’). These cysts can either get infected and form pus collections, have bleeding within them, develop stones inside them, rupture and burst open or become cancerous. These are well known complications of these cysts.
All of these complications result in kidney pain of various intensities. Kidney cysts and their complications are diagnosed by ultrasound, CT scan, urine tests and blood cultures. Depending on the complications, they are treated by painkillers, antibiotics, bedrest, surgery or chemotherapy.
Hence, kidney pain is rare but every back pain needs to be evaluated to rule out kidney related causes. For those interested – it turned out that the young man who visited my office (as mentioned in the beginning) had musculoskeletal pain due to excessive gymming and not due to kidney pain!