Decreased urination is often caused by dehydration. But sometimes it may indicate a more serious disease.
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
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.
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.
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.
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.
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.
Decreased urination is not catching, so there are no risks to others.
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.
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.
Treatment usually cures a person with dehydration. An individual with kidney failure often needs lifelong dialysis.
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.