The kidneys play a number of important roles in the body beyond the formation and excretion of urine to expel wastes in the body. Without adequate kidney function, homeostasis cannot be maintained in the body. The kidney also has the following functions :
- Regulates the blood pressure.
- Controls the acid-base balance of the body fluids including the blood, intracellular (within cells) and interstitial (tissues) fluid.
- Influences the osmotic gradient (osmolality) between fluids in different compartments thereby impacting on fluid distribution.
- Hormone secretion which influences several processes including calcium and phosphate levels and red blood cell production. These hormonal functions are separate to the adrenal glands located at the top of each kidney, which may also be affected with certain types of kidney diseases.
Therefore kidney diseases will also cause of a host of signs, symptoms and secondary disorders of various other systems.
Types of Kidney Problems
Severe kidney diseases can be divided into :
- Acute renal failure where the kidneys suddenly stop working completely or almost entirely but normal functioning can be restored with proper treatment and time. With acute renal failure the production and flitering of urine is not possible and there is little or no urine passed (oliguria or anuria). Urea and other nitrogenous wastes build up in the blood stream (uremia).
- Chronic renal failure where there is a gradual loss of kidney function due to a diminishing number of competent nephrons (the basic filtration unit of the kidney). This is often irreversible. Uremia also arises along with a host of generalized signs and symptoms.
Kidney diseases are categorized in several ways based on the effect of kidney and manner in which kidney function is disrupted. This extends beyond acute and chronic renal failure and may give rise to a host of different signs and symptoms.
- Nephritic syndrome arises with glomerular inflammation (glomerulonephritis) and typically seen in acute conditions like an infection.
- Hematuria – blood in urine
- Proteinuria – protein in urine
- Hypertension – high blood pressure
- Edema – swelling
- Nephrotic syndrome arises with damage to the glomerulus as may be seen with glomerulonephritis or several disorders that either directly or indirectly damage the kidney.
- Heavy proteinuria – excessive protein in urine
- Hypoalbuminemia – low blood proteins
- Severe edema – excessive swelling
- Renal tubular disease may be due to structural defects of the tubules or functional disturbances in the renal tubule. It can arise due to a number of causes including inherited and acquired factors.
- Polyuria – large volume urination
- Nocturia – waking at night to pass urine
- Acidosis/alkalosis – acid-base balance in blood affected
Other kidney diseases include :
- Kidney infections
- Kidney stones
- Urinary tract obstruction
- Renal tumors
Signs and Symptoms of Kidney Disease
Kidneys upper urinary tract :
- Pain, also described as loin, flank or lumbar pain. Read more on kidney pain location.
- Edema, which is swelling of the legs, ankles and feet or even around eyes.
- Gross hematuria, which is clearly visible blood in the urine.
Lower urinary tract :
- Dysuria – pain when passing urine.
- Urinary frequency – passing urine often more frequently than normal.
- Polyuria – passing more urine than normal (high daily volume).
- Oliguria – passing less urine than normal (low daily volume).
- Anuria – total absence of urine output.
- Pneumaturia – gas in the urine.
- Urethral discharge – pus and/or mucus from the urethra.
- Urgency – urgent need to urinate.
- Nocturia – waking at night to pass urine.
- Hesitancy – delay in starting urination.
- Post-micturition dribbling – passing of small quantities of urine after urination.
- Urinary incontinence – involuntary passing of urine.