The kidneys are bean shaped organs that serve several important regulatory roles in vertebrate animals. They remove excess organic molecules (e.g., glucose) and thus remove the waste products of metabolism (e.g., urea, though 90% of this is reabsorbed along the nephron).
They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and regulation of blood pressure (via maintaining water and salt balance).
They are natural filters of the blood, and remove water soluble wastes, which are diverted to the urinary bladder. The kidneys excrete wastes such as urea and ammonium through the urine, and are also responsible for the re-absorption of water, amino acids, and glucose.
They also produce hormones including calcitriol, erythropoietin, and the enzyme renin (which indirectly acts on the kidney in negative feedback).
Located at the rear of the abdominal cavity in the retroperitoneum, the kidneys receive blood from the paired renal arteries, and drain into the paired renal veins. Each kidney excretes urine into a ureter, which is a paired structure that empties into the urinary bladder.
The study of kidney function is called renal physiology, while nephrology is the medical specialty concerned with kidney diseases. Many clinical conditions involving the kidney include the nephritic and nephrotic syndromes, acute kidney injury, renal cysts, urinary tract infection, urinary tract obstruction, chronic kidney disease, and nephrolithiasis.
There are various cancers of the kidney and the most common adult renal cancer is renal cell carcinoma. Cysts, cancers, and some other renal conditions can be managed with nephrectomy (removal of the kidney).
Dialysis and kidney transplantation are treatment options when the renal function, measured by glomerular filtration rate, is persistently poor. Although they are not considered harmful, kidney stones can be painful, and if repeated, chronic formation of stones can scar the kidneys.
The removal of kidney stones involves ultrasound treatment which breaks the stones into smaller pieces, which are later passed through the urinary tract. One common symptom of kidney stones is a sharp pain in the medial/lateral segments of the lower back or groin.
There are simple ways to reduce the risk of kidney disease, some of which are:
1. Consume healthy foods like fruits, vegetables, nuts and lean meat
2. Regular exercise
3. Keep your blood sugar level under control
4. Try to keep a low blood sugar
5. Drink lots of water and lower your salt intake
6. Quit smoking
7. When possible, try natural remedies instead of over the counter pills
8. Check your kidney functions regularly
9. Have regular kidney checks if you have a family history of kidney disease
