Protein in the urine, also known as proteinuria, may be a sign of chronic kidney disease resulting from diabetes, high blood pressure, and other conditions that cause inflammation of the kidneys, according to the National Kidney and Urologic Diseases Information Clearinghouse. While proteinuria does not have any symptoms in the early stages, substantial levels of protein can cause foamy urine. Protein in the urine is also a primary sign of preeclampsia in pregnant women.
Temporary elevated levels of urinary protein are not unusual and may occur in younger people during an illness or after exercise, according to the Mayo Clinic. Protein in the urine is also often one of the earliest signs of kidney damage due to diabetes.
Protein in the urine can also occur with preeclampsia, a condition that only occurs during pregnancy, according to the American Pregnancy Association. Preeclampsia, also known as toxemia, can occur after the 20th week of pregnancy and is characterized by protein in the urine and high blood pressure. While there are a number of risk factors associated with preeclaampsia, any pregnant woman can develop this condition. Risk factors for preeclampsia include a family or personal history of preeclampsia, a first pregnancy, being over the age of 40, obesity, diabetes and having a "multiples" pregnancy, according to the American Pregnancy Association.