Leukocytes in your urine is often sign of a urinary tract infection (UTI). Leukocytes are simply white blood cells and are diagnosed with a urinalysis. They are there to fight off the bacteria that have caused the infection. The infection that caused the leukocytes to be there in the first place can be treated with antibiotics for about a week's time, clearing the infection up, thus allowing the white blood cells to vacate your kidneys and urine.
There are a few different types of urinary tract infections that can cause leukocytes to be in your urine. Kidney infections, urethritis and cystitus are the three most common urinary tract infections. Normal leukocyte levels in your urine usually are around 0-10 lev/vl and when they approach and exceed 20 lev/vl there is a definite issue. They are there to fight off infection, which is a good thing. The bad thing is diagnosing the infection and figuring out what caused it.
Urinary tract infections are caused by a few different things. Intercourse is a common cause. During intercourse, bacteria can sometimes be massaged into the urethra. This bacteria then causes the infection to take hold. Another cause is waiting too long to urinate which causes the bladder to overstretch. The bladder weakens and will not empty all the way. The leftover urine will cause bacteria to form and cause the infection to take place in either the urinary tract or bladder itself. Be aware that sometimes urinary tract infections occur because of pregnancy. So a pregnancy test might be a good idea as well.
Prevention and Treatment
Avoiding these situations, if at all possible, is the only way to avoid urinary tract infections and the presence of extra leukocytes to combat the infection itself. Most women experience urinary tract infections because the causes of them are so many, and with a week's dose of antibiotics, it will clear the infection right up.