Decreased Urination

Decreased urination is often caused by dehydration. But sometimes it may indicate a more serious disease.

What is going on in the body?

The kidneys produce urine by filtering the blood. Decreased urination is usually related to one of three problems:

blockage in the tubes that carry urine from the kidneys to the outside of the body

insufficient blood reaching the kidneys, so they cannot make urine

kidney damage, which makes the kidney unable to filter

What are the causes and risks of the condition?

Causes of decreased urination can be divided into three categories:

Insufficient amounts of blood reaching the kidneys. This may be due to:

blood loss

dehydration from vomiting, diarrhea, excessive sweating, or inability to take in fluids. Medicines, such as a diuretic, or water pill, can also cause dehydration.

a heart that cannot pump enough blood to the kidneys, which can occur in congestive heart failure

low blood pressure from shock or a serious infection. Medicines, such as those used to treat high blood pressure, can also cause low blood pressure.

Kidney damage. This may be due to:

acute tubular necrosis, a type of kidney injury caused by low blood pressure. Another common cause is a substance that is toxic to the kidney. Examples are the antibiotic gentamicin, the metal mercury, or iodine, which is commonly used in certain X-ray tests.

autoimmune disorders, which means that a person’s immune system attacks his or her own body. An example is systemic lupus erythematosus, or lupus, a condition that can affect many areas of the body.

cancer or tumors involving the kidneys

chronic renal failure, which is usually a complication of long-standing diabetes or high blood pressure. An inherited condition called polycystic kidney disease is another cause of kidney failure.

glomerulonephritis, another type of kidney damage that may occur after an infection

Blockage in the tubes that carry urine from the kidney. This may be due to:

cancer or a tumor in the bladder or prostate

kidney stones that affect both kidneys, which is rare

prostate enlargement, also called benign prostatic hyperplasia, a common condition in men older than 40

Other causes are also possible. Sometimes, the cause cannot be found.

What are the signs and symptoms of the condition?

To determine the cause of the decreased urination, a healthcare provider may ask questions such as:

when the condition started

whether it started suddenly or gradually

what the urine looks like, such as a darker color than usual

whether there is any family history of decreased urination

how much urine the person thinks he or she is producing each day

how often the person has the urge to urinate

what other medical conditions the person has

what medicines or drugs the person takes

what other symptoms the person has

Other types of questions may also be asked.

How is the condition diagnosed?

Diagnosis begins with a medical history and physical exam. This may be all that is needed to figure out the cause. In other cases, further testing is needed. Different tests may be ordered, depending on the suspected cause.

Blood and urine tests are commonly ordered. Sometimes, the urine is collected over a 24-hour period to get an exact measurement of the amount of urine being made. Special X-ray tests of the kidneys and bladder may also be done.In some cases, a procedure called a kidney biopsy is needed. A special needle is inserted through the skin and into one of the kidneys. A small piece of the kidney is then removed with the needle. The piece is sent to the lab for examination to help figure out the problem.

What can be done to prevent the condition?

Prevention depends on the cause. Avoiding certain medicines can prevent some cases.Drinking enough fluids can prevent cases due to dehydration. Effective treatment of diabetes and hypertension can prevent some cases due to kidney failure. Many cases cannot be prevented.

What are the long-term effects of the condition?

Long-term effects are related to the cause. Most cases of dehydration can be treated, and the amount of urine returns to normal. In these cases, there usually are no long-term effects.

A person who has kidney failure may need a kidney transplant or dialysis. Dialysis is a procedure to filter the blood. The person usually has surgery first and is then hooked up to a blood-filtering machine three times a week. In these cases, the decreased urination is usually permanent.

If the cause is a serious infection or cancer, death may result.

What are the risks to others?

Decreased urination is not catching, so there are no risks to others.

What are the treatments for the condition?

Treatment is directed at the cause. A person who is dehydrated is given fluids. Fluids can be given through an intravenous line if the person is unable to drink. An intravenous line is a thin tube that is inserted through a person’s skin and into a vein, usually in the hand or forearm.

Someone with an infection may be given antibiotics.

A person with a tumor or prostate enlargement may need surgery.

A person with kidney failure usually needs a kidney transplant or dialysis.

What are the side effects of the treatments?

Side effects depend on the treatments used. Antibiotics may cause an allergic reaction or stomach upset. Any surgery carries a risk of bleeding or infection. Dialysis has many risks, including salt imbalances, infection, and death.

What happens after treatment for the condition?

Treatment usually cures a person with dehydration. An individual with kidney failure often needs lifelong dialysis.

How is the condition monitored?

The amount of urine output can be monitored closely if needed. Other monitoring is related to the cause. For example, a person with diabetes needs frequent blood tests to monitor blood sugar levels.