Causes of Epithelial and Squamous Cells in Urine

Squamous epithelial cells are cells that line the inside and outside of different parts of your body. You have them on your bladder, urethra, and parts of your kidneys. It’s normal to have a small amount of these cells in your urine, but when their numbers rise, it can be sign of a problem.

A UTI is an infection in any part of your urinary tract, including your kidneys, ureters, bladder, or urethra. Infections cause inflammation and irritation in your urinary tract, which makes the cells in its lining shed into your urine. It’s normal to have a small number of epithelial cells in your urine, but having more than a certain amount can be a sign of a problem like a UTI.

If there’s a tumor growing in your bladder or other part of your urinary tract, it gets in the way of the normal process of old cells being replaced with new cells. This increases the epithelial cells in your urine. Although this can be a sign of bladder and other cancers, doctors don’t only use urine results to diagnose cancer. 

Car accidents, falls, punctures, injuries to your body that don't pierce the skin — these are all ways your kidney or ureters might be injured. Epithelial cells shed when this happens, and they show up in your urine. 

Chemotherapy for cancer treatment uses chemicals to kill fast-growing cells in your body. When you’re on it, you lose epithelial cells in your urine.

When bacteria causes infections in your ureters or bladder, the infection can travel to your kidneys, causing a kidney infection (pyelonephritis). Kidney infections can damage your kidneys and cause epithelial cells to shed into your urine.

Kidney stones are hard clumps of salt and minerals that form in your kidneys. They happen when your urine has more crystal-forming substances than fluid to dilute them. Unless they’re too big to pass through your system and require surgery, kidney stones come out of your body when you pee. Passing kidney stones causes epithelial cells to build up in your urine.

When you pee into a cup for your urine sample, sometimes epithelial cells get in the sample from the outside of your body. This contaminates the sample and makes it seem like you have too many epithelial cells in your urine. This is most common in men who aren’t circumcised, but it can also happen if you don’t collect your sample properly.