Frequent urination and problems with the kidneys are closely connected, as the kidneys are the organs that produce urine. The symptom of frequent urination may be caused by problems such as kidney disease or a urinary tract infection. It also may be the case that frequent urination has little to do with the kidneys, being caused, for instance, by an enlarged prostate or due to side effects of certain medications.
The kidneys are two oval-shaped organs, usually 4-5 inches long, and located at the back of the abdomen. All the blood in the human body passes through the kidneys several times daily, and it is here that the blood is filtered and cleaned. The kidneys also control the body's fluid balance and regulate electrolyte levels. As the kidneys filter blood and regulate fluids, urine is formed which moves from tubes called the ureters into the bladder where it is expelled from the body. Since the kidneys produce urine, frequent urination and the kidneys may be connected.
Individuals experiencing frequent urination suffer from the need to urinate more often than usual. This may occur during the day or night, or in some cases, only at night. Usually, the overall amount of urine expelled is the same or less than is typical rather than more.
One connection between frequent urination and the kidneys is kidney disease. Those experiencing kidney disease may also experience frequent urination. Kidney disease may be caused by long-term, uncontrolled high blood pressure or diabetes, or it can also be congenital, meaning that one can be born with a kidney abnormality. Symptoms of kidney disease include frequent urination and difficulty urinating, blood in the urine, and swelling of the extremities. A doctor will perform further tests to confirm kidney disease.
Another connection between frequent urination and the kidneys is a urinary tract infection. Urinary tract infections which affect the lower urinary tract are known as cystitis. In the upper urinary tract, they are known as pyeionephritis.
The upper urinary tract includes the kidneys, which is why this type of infection is sometimes called a kidney infection. Usually the infection begins in the bladder as a lower urinary tract infection and, left untreated, moves into the kidneys, creating an upper urinary tract infection. In a lower urinary tract infection, symptoms generally include frequent urination, pain while urinating, and a low fever. If the infection moves to the kidneys, symptoms may include chills, fatigue, and nausea with a high fever.
There are also some conditions in which there is not a direct connection between frequent urination and the kidneys. In men, an enlarged prostate can press against the urethra, irritating the bladder and causing frequent urination. Certain medications, such as diuretics, encourage the body to expel fluids. Some frequent urination is caused by bladder contractions.