Kidneys are two-bean shaped organs that are usually found underneath the surface of the middle and low back region of the body.The right kidney is slightly lower in position than the left kidney in the abdominal cavity due to the presence of the liver on the right side of the cavity. But they are both partially protected by the lower part of the ribcage. They are small organs that make up less than 1 per cent of the total body weight. Though they are small in the whole body, kidneys are among the organs that receive close to 30 per cent of the total amount of blood especially at rest.Probably this is the reason why when you take in a lot of drinks at night you are forced to wake-up to go for urination.When the heart pumps, there is large amounts of blood delivered to the kidneys and is transported by renal arteries. Inside the kidneys, the renal arteries split up into a number of smaller branches that distribute blood to the nephrons. The nephrons are microscopic processing units of the kidneys and all together make up 1 million per kidney.The nephrons are comprised of a network of capillaries and all together form the glomeruli. The glomeruli filter the blood and pass the filtrate on to a series of specialised tubules that are collectively known as the renal tubule. This is where urine is created.The basement membrane of the glomeruli that filters blood in the kidneys makes sure the whole blood reaching the kidney is filtered. The filtrate usually includes waste materials, water, chloride ions, sodium ions, bicarbonate ions, glucose, potassium ions, urea, uric acid, and protein. About 99 per cent of these products are re-absorbed in blood back into blood circulation. This shows the workload done by the kidneys in your body.Once urine is created in the renal tubules, it passes through a series of collecting ducts until it reaches the inner middle section of the kidney where urine is collected by the ureter. The ureters transport urine from the kidney into the bladder from where it can be released by the body. From the bladder, urine exits the body through the urethra.It is now understood that one of the major functions of the kidney is urine excretion, one of the dangerous waste products.This also reminds us why taking a measurable amount of water is very important in the body as it allows kidneys to carry out this function properly.Many people think that taking a lot of water will result into eminent removal of waste products. However, it should be understood that the kidneys are not like plumbing tube that can be cleaned by flushing in large amounts of water but it is rather a process and a complex process.For a healthy human being, it is very necessary to prevent unnecessary burden to the kidneys and other vital organs like the liver that eliminates waste products from the body.A part from urine removal in the body, kidneys do perform other duties. We have seen that mineral contents of the body are also found among the filtrates from the glomerulus membrane. The kidneys help to maintain a proper balance of electrolytes and fluids throughout the body.The kidneys are known to secrete a hormone called erythropoietin that stimulates the production of red blood cells in the bone marrow. The kidneys produce rennin needed for maintenance of blood pressure and this is why patients with kidney problems are persistently checked for hypertension or blood pressure.However, there are substances such as medications that burden or can affect kidneys, especially on long term use.Most of the non-steroidal anti-inflammatory drugs such as the ibuprofen, naproxen, acetaminophen and aspirin are known to cause kidney damage. However, all these pain killer medications should be used in emergency situations, especially when kidneys are normal.  Protein consumption should always be checked as it produces urea as one of its end products of metabolism. This means increase of protein consumption or protein components in blood will create a workload on the glomerulus membrane. The workload can lead to the rupture of this filtering membrane and many problems can arise from here.People with kidney problems are advised to consume very little protein containing food substances.Dr. Joseph Kamugisha is a resident oncologist based in Jerusalem, Israel