Renal--or kidney--insufficiency can be either chronic or acute. Acute renal insufficiency occurs suddenly, and may be reversible in some cases. Chronic renal insufficiency, on the other hand, is a slow deterioration of the kidneys that takes place over months or even years. Either type can damage the kidneys if left untreated or allowed to progress for any length of time.
Low Urine Output
Decreased urine output can be a symptom of either chronic or acute renal failure. As the amount of urine decreases, it may develop a strong odor. The color of the urine is also an indicator that something may be wrong. The more water or fluid the kidneys are able to filter, the lighter the color will be. When the amount of water being filtered is reduced, urine becomes concentrated. This can cause it to appear very yellow, orange or brown, which may indicate that blood is present in the urine and a physician should be seen immediately.
A reduction in the amount of urine produced may also mean that toxins and wastes are building up in the body and tissues. This can lead to illness, infection and a compromised immune system.
Edema
When kidneys are damaged or under stress, they are unable to adequately eliminate salt and other wastes produced by the body. This causes urine output to decrease and fluid levels in the body to build up. When fluids are trapped in tissues throughout the body, swelling occurs. This particular type of swelling, known as edema, usually occurs in the legs, feet, arms and hands.
Edema can put pressure on the heart and circulatory system and may eventually lead to hypertension or other cardiovascular problems.
Pain
In many cases, there may be little or no pain until the disease has progressed to the point that the kidneys are struggling to function. Back pain associated with the kidneys is located a few inches down from the ribs and on either side of the spinal column. As kidney diseases progresses, the pain may go from a dull ache to a piercing pain.
Painful cramping of the muscles can also occur if potassium and other minerals are not filtered properly and excreted from the body. When these are allowed to accumulate in the body, swelling may occur that causes discomfort and can disrupt circulation to those areas of the body.
