The main function of our kidneys is to produce urine through which the body gets rid of metabolic wastes. The kidneys also play a critical role in maintaining homeostasis by regulating the amount of water and salts that are lost through urine. Both of our kidneys work continuously through day and night to filter the blood in order to produce urine. Due to the critical nature of the functions that the kidneys are responsible for, any kidney dysfunction can result in serious consequences.
The human body can continue to work even with one healthy kidney. Therefore, damage to a kidney may not always be evident in the early stages of a disease. Overt signs and symptoms typically arise when the kidney dysfunction becomes severe. However, treatment of later stages of kidney diseases is difficult. Therefore, it is important to identify the subtle signs of a kidney problem at an early stage, so that the condition can be treated effectively.
Kidney dysfunction can occur due to a variety of causes.
It is also rare for the entire kidney to become immediately diseased due to a single condition. More frequently, kidney dysfunction arises due to problems in certain parts of the kidney or its associated structures, such as the renal blood vessels, kidney tissue, or ureters. Regardless of which part of the kidney is affected, the symptoms of a kidney dysfunction are usually the same.
Whenever a kidney problem is suspected, it is advisable undergo an examination by a doctor. Although over-the-counter, consumer-grade urine dipstick tests may reveal a general problem with the kidneys or urinary system, a professional medical examination by a doctor is required to identify the nature of the exact problem and determine an effective treatment regimen.
Read more on signs of kidney disease.
How To Spot Unhealthy Kidneys
Diagnosis of a kidney problem is best done by a medical professional. A doctor will use urine tests, blood tests, and various scans in order to arrive at a diagnosis. However, there are some signs and symptoms that one should be aware of in order to suspect that something is wrong with the kidneys in the first place. An individual who experiences such signs and symptoms can then approach a doctor for a thorough medical investigation.
Changes in the normal color of urine
The normal color of urine in humans is pale yellow. Drinking more water lightens the yellowish color of the urine, and may even make it appear as clear as water. When the water intake drops below the normal requirement of the body, the yellowish color of the urine becomes stronger, resulting in dark yellow urine. These are normal colors of urine under different physiological conditions.
In diseased conditions, the urine may show abnormal colors, such as pink, red, brown, orange, or black. When the urine displays such abnormal colors, one should get a medical checkup done. A pink or red-colored urine is usually more common, and indicates the presence of blood in the urine (also referred to as hematuria). However, not all occurrences of blood in the urine change the color of the urine.
Presence of abnormal substances in the urine
Normal urine is composed predominantly of water (around 95%), and solutes such as urea (2%), creatinine, uric acid, ammonia, calcium, magnesium, chloride, sodium, phosphate, and sulphate. Metabolic byproducts of drug metabolism may also be present in minor quantities. These are all normal constituents of urine. When urine contains protein or blood cells, then there is likely to be an abnormality in the kidneys or somewhere else in the urinary system.
The presence of blood in the urine may change the normal color of the urine. However, this is not always the case. The presence of proteins in the urine (technically referred to as proteinuria) can cause the urine to turn foamy or frothy. The presence of pus in the urine (due to an infection) can make the urine appear murky or cloudy. A cloudy urine may also be a result of excess calcium, protein, or vaginal discharge in the urine.
Changes in the volume of urine
We normally pass out anywhere between 500 milliliters to 3 liters of urine every day. The exact volume of urine produced depends on the volume of liquids we consume every day. An adult who drinks 2-3 liters of water on a daily basis typically excretes 1.5-2 liters of urine daily. Rest of the water loss occurs through sweat, stool and breath. The volume of water one drinks depends on factors such as environmental temperature and amount of physical activity. Kidney problems can lead to excretion of less than 500 milliliters or more than 3 liters of water per day.
Urine production in excess of 3 liters per day is technically referred to polyuria, whereas urine production of less than 500 milliliters per day is technically referred to as oliguria. In some cases, urine production may drop to less than 50 milliliters per day or may even cease completely. Such a condition is technically referred to as anuria. The capacity of a normal adult human bladder is about 500 milliliters. Therefore, a person suffering from polyuria will display a higher frequency of urination. At times, one may also wake up at night to pass urine (a condition known as nocturia).
Abnormal odor in urine
The odor of urine varies based on fluid intake, environmental temperature, types of foods consumed, and level of physical activity. When the fluid intake is sufficient, the urine may not have any strong odor. Concentrated urine has an ammonia-like odor that is caused by the presence of urea.
The more concentrated the urine, the stronger the ammonia-like odor. However, this is entirely normal odor for the urine. The odor of urine becomes abnormal when it is an offensive fish-like smell or a sweet smell. Apart from kidney diseases, diabetes, liver disease, and many other non-renal conditions can also cause an abnormal urine odor.
Pain or burning sensation
Kidney pain is hard to isolate in the abdominal region because of the presence of many other neighboring structures. Usually, kidney pain tends to affect the flanks of the abdominal wall, as well as the back region. Pain in these areas should, therefore, be investigated promptly.
As the position of the kidneys change while sitting, standing, and lying down, the location of the pain may also change. A burning sensation during urination is rarely a sign of a kidney problem. It is more likely to be caused by infections of the lower urinary tract. However, untreated urinary tract infections may at times reach the kidneys.
Read more on kidney pain location.
Swelling, nausea, and shortness of breath
Kidney dysfunction can affect the fluid homeostasis in the body. This can result in swelling of the legs, caused by retention of excess fluid in tissues. Buildup of waste products (such as urea) within the blood due to kidney dysfunction can also lead to nausea. As the pH of the blood changes, shortness of breath may occur, which can further lead to rapid breathing. Other signs of kidney problems include muscular cramps, headaches, fatigue, pale sallow complexion, confusion and seizures.