The kidneys keep the body’s chemistry in balance by removing waste products and excess water. They also regulate blood pressure and stimulate red blood cell production. The body can stay healthy with one normal kidney, but many conditions affect both kidneys and it is therefore important that kidney disorders are treated promptly.
The first article in this section covers pyelonephritis, a common disorder in which kidney tissue becomes inflamed, usually due to a bacterial infection. Glomerulonephritis, which develops when inflammation damages the glomeruli (the kidneys’ filtering units), is discussed in the second article. This condition nearly always results from the response of the kidneys to the activity of the immune system.
The next articles discuss stones and cysts in the kidneys. Kidney stones are often treated by a technique called lithotripsy, in which shock waves are used to pulverize the stones. Cysts are usually harmless, but multiple cysts resulting from a genetic disorder may cause kidney failure. The final articles cover cancer of the kidneys and kidney failure. The latter disorder may occur suddenly, especially if it results from a reduction in the blood flow to the kidneys, but more often it develops gradually due to a chronic disease such as diabetes mellitus. Kidney infections in children and the rare kidney cancer called Wilms’ tumour are discussed in the section on infancy and childhood.
For more information on the structure and function of the kidneys, see Urinary System.
Urinary disorders are very common. The symptoms may include an increased need to empty the bladder, urinary leakage, blood in the urine, and pain during and after urination. These symptoms can often disrupt daily routine. However, most disorders of the bladder and urethra (the passage from the bladder to the outside of the body) are curable or at least controllable by treatment.
The first article in this section deals with cystitis, a condition in which the bladder becomes inflamed. Cystitis is often due to infection by bacteria from the skin around the anus. Women are particularly susceptible to the disorder because the female urethra is short and close to the anus, allowing bacteria to enter easily. In men, bladder infections are often related to an obstruction due to an enlarged prostate gland.
The next three articles cover urinary incontinence. There are several types of incontinence, all of which are more common in women and in older people of both sexes. Structural disorders are covered in the next articles; they include stones that form in the bladder and strictures that narrow the urethra, making the passing of urine difficult. The last article in this section covers bladder tumours.
Sexually transmitted infections that affect the male urethra are discussed elsewhere (see Sexually transmitted infections). Urinary tract problems that occur in children are covered in the section Reproductive and urinary system disorders.
For further information on the structure and function of the bladder and urethra, see Urinary System.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.